kava - the unfolding story: report on a work-in-progressclok.uclan.ac.uk/9455/1/kava...
TRANSCRIPT
Article
Kava shy the unfolding story Report on a workshyinshyprogress
Denham Alison McIntyre Michael and Whitehouse Jule
Available at httpclokuclanacuk9455
Denham Alison McIntyre Michael and Whitehouse Jule Kava shy the unfolding story Report on a workshyinshyprogress Journal of Alternative and Complementary Medicine 8 (3) pp 237shy263
It is advisable to refer to the publisherrsquos version if you intend to cite from the work
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SPECIAL REPORT
THE JOURNAL OF ALTERNATIVE AND COMPLEMENTARY MEDICINEVolume 8 Number 3 2002 pp 237ndash263copy Mary Ann Liebert Inc
Kavamdashthe Unfolding Story Report on a Work-in-Progress
ALISON DENHAM BA (Soc) MNIMH1
MICHAEL McINTYRE MA FNIMH FRCHM MBAcC2
and JULIE WHITEHOUSE PhD MNIMH3
ABSTRACT
This paper originated as a submission (now updated) to the UK Medicines Control Agencyand Committee of Safety of Medicines (CSM) on January 11 2002 in response to a report circu-lated by the German Federal Institute for Drugs and Medical Products (German initials are BfArM)a compilation of which is summarized in Appendix 2 This agency issued notification in late No-vember 2001 of some thirty adverse events associated with the use of concentrated standardizedpreparations of kava (Piper methysticum Forst f) reported from Germany and Switzerland Ananalysis of the summary of the BfArM case reports (see Appendix 2) shows that these contain du-plications among the cases cited The original submission that was sent to the CSM January 2002has been updated to the version published here This new version was completed in April 2002
As a result of the alert from BfArM the evaluation of kavarsquos safety is now occurring on aworldwide basis and being that this a matter of considerable importance to the public the healthcare community and regulatory authorities as well as to kava farmers throughout Polynesia itis it important to depict this progress report As such this updated report does not provide fi-nal answers The material released by the BfArM is lacking in detail however it is hoped thatthis report will shed light on the kava controversy It is anticipated that there will be further up-dates shortly
This report prepared on behalf of the Traditional Medicines Evaluation Committee a subcom-mittee of the European Herbal Practitioners Association argues that many of the adverse eventscited by the BfArM should not be attributed to kava In addition the report states that the prop-erties of concentrated standardized kava extractsmdashas opposed to preparations that closely ap-proximate those created for traditional usemdashcontribute to causing adverse events This report pro-poses a number of simple measures that will ensure that safe kava preparations may continue tobe available in the United Kingdom
237
BENEFITS OF KAVA
Kava (Piper methysticum Forst f) is an im-portant herbal medicine with unique
properties The ability of herbal practitioners to
care for their patients would be significantly af-fected if this herbrsquos use were restricted or cur-tailed so that practitioners were unable to pre-scribe it Since the early 1900s kava has beenused in Britain by herbal practitioners mainly
1University of Central Lancashire Preston United Kingdom2Midsummer Cottage Clinic Oxon United Kingdom3University of Westminster London United Kingdom
for urinary problems (Ellingwood 1919) Theindications given in the British Herbal Pharma-copoeia (Anonymous 1983) are ldquoCystitis Ure-thritis Rheumatism and Infection of the gen-ito-urinary tractrdquo More recent texts emphasizethe herbrsquos usage as a nervine For example in-dications given by Mills and Bone (2000) areldquoanxiety of nervous origin nervous tensionrestlessness or mild depression of non-psy-chotic origin menopausal symptoms and in-flammation and infections of the genitourinarytracts of both men and women muscular andnervous pain and insomniardquo Kava use as anervine (which is its traditional therapeuticuse) has increased markedly in recent yearspartly because of the evidence for clinical effec-tiveness found in clinical trials (Pittler and Ernst2000) However it is interesting to note thatsuch usage is not completely new Felter (1905)notes kavarsquos application inter alia for treatingneuralgia dizziness and despondency Theherb has a particular value for treating agita-tion and anxiety (Spinella 2001) when othernervines have proved to be ineffective
Clinical trials have been reviewed recentlyby Pittler and Ernst (2000) who stated that for treating anxiety kavarsquos superiority overplacebo was suggested by all seven trials un-der review and that for the three trials in-cluded in the meta-analysis there was a sig-nificant reduction in score on the HamiltonAnxiety Scale The clinical trials were all car-ried out in Germany where kava is prescribedby physicians and sold over the counter inpharmacies for treating anxiety and insomniaA recent review (Loew 2002) listed nine dou-ble-blinded randomized controlled trials in-volving 808 patients and stated that kava wassignificantly superior to placebo for treatingsymptoms associated with anxiety These trialsused a range of products standardized on15ndash70 kavalactones providing a dailydosage of 60ndash210 mg per day of kavalactonesThe use of kava is being increasingly advocatedas an alternative to benzodiazepines for treat-ing anxiety and has been tested in at least onetrial (Loew 2002) The trial was 28 days longand involved 61 people And for example DeLeo et al (2001) showed a significant relativedecrease in anxiety in a double-blinded ran-domized trial on 40 menopausal women when
kava was combined with hormone replacementtherapy This trial lasted for 6 months and thedosage of kava extract was 100 mg per day (con-taining 55 mg of kavain) It has been claimed thatthe German Federal Institute for Drugs and Med-ical Products (German initials are BfArM) citeddoubts about kavarsquos efficacy for treating anxietyas one reason for starting an investigation on theherb (Anonymous 2001) Surprise was ex-pressed in Germany for this reason because itwas claimed (Anonymous 2001) that a recentrandomized controlled trial awaiting publicationhad demonstrated kavarsquos efficacy for this use atdoses that conform to the Commission E mono-graph on the herb (Blumenthal 2000)
The modern use of kava as a nervine is in ac-cordance with its traditional usage in the SouthPacific Kava drinkers report a sense of relax-ation and tranquillity and manifest a sociableattitude (Chanwai 2000) The herb is used as asocial and ceremonial drink among men inPolynesia In modern times as the influence ofthe Christian missionaries decreases kavarsquosuse has become more widespread and fre-quent For instance Kava is an important partof social life in Fiji Fijian spiritual leaders arecalled dauvaguna the literal translation ofwhich means ldquoexpert at drinking kavardquo(Greenwood-Robinson 1999) Kava is not ad-dictive and does not seem to produce the vio-lent antisocial effects that alcohol produces(Lebot et al 1997) However there are seriousconcerns in Australia (Clough et al 2000)about the herbrsquos abuse as a recreational drugwhen it is used to excess It has been associatedwith inactivity confusional states and generalill-health possibly as a result of associated mal-nutrition caused by irregular eating habits(Chanwai 2000) In Aboriginal communitiesmalnutrition is not uncommon and this associ-ation is considered to be unproven
WHAT IS KAVA
Root bark and root of kava are used eitherfresh or dried for its preparation
Based on an archaeological study of charac-teristic drinking bowls it has been proposedthat the herb was first domesticated in Polyne-sia more than 2000 years ago (Green 1974 [cited
DENHAM ET AL238
in Lebot et al 1997]) A comprehensive surveyby Lebot and Levesque in 1989 (cited in Lebotet al 1997) suggests that kava was originallydomesticated in the Vanuatu islands
Kava is now obtained from a wide range ofcultivars in the South Pacific The plant is al-ways propagated vegetatively from stem cut-tings as it does not reproduce via fertilizationmethods There are many cultivars and newstrains continue to be developed by Polynesianfarmers because each strain is considered tohave different psychoactive effects
In recent years there has been increasingpressure on the market because of the increasedworldwide demand for kava In 1998 it wasamong the top-selling herbs in the UnitedStates with a turnover of $8 million repre-senting a growth rate of 473 (Pittler and Ernst2000) It is possible that the current hepatotox-ity problems are to some extent a consequenceof poor quality control caused by a rapid andextraordinary increase in the size of the market(Murray 2000)
There are also concerns that intensive culti-vation and harvesting may affect the quality ofthe product (Aarlbersberg 1999) However be-ing that a range of products is implicated thisis unlikely to provide a satisfactory explanationfor all the reported adverse reactions It ishoped that the BfArM will release relevant dataabout the source and quality assurance of thekava supply in due course
KAVA PHARMACOLOGY
Kava is a well-researched herb The crys-talline resin was first isolated in 1857 by aFrench naval pharmacist and a detailed mono-graph was published in 1886 (Lewin 1886[cited by Lebot et al 1997]) The kavalactonesare considered to be the active constituents andhave been shown in animal studies to have asedative action (Hansel 1996) although themechanism is unclear (Spinella 2001) Thekavalactones are found in the resinous portion(5ndash9) of the plant material and are poorlysoluble in water
Kavalactones are 4-methoxy-2-pyrones withphenyl or styryl substituents at the 6th position(Lebot et al 1997) Total kavalactone content
varies from 3 to 20 dry weight Eighteen lac-tones have so far been isolated (He et al 1997)with the following six compounds (includingfour chiral enantiomers and two achiral enan-tiomers) being considered most important(Haberlain 1997 see Fig 1)
Chiral enantiomers(1) (1)-kavain(2) (1)-dihydrokavain(3) (1)-methysticin(4) (1)-dihydromethysticin
Achiral enantiomers(5) yangonin(6) demethoxyangonin
TRADITIONAL PREPARATION TECHNIQUES
Kava is traditionally prepared in the SouthPacific by grinding and mixing the root or rootbark with cold water This makes an emulsionthat is a suspension of the resinous constituentsin water (Lebot et al 1997) The herb is alsoprepared as an emulsion (also traditionallyprepared without heating) in coconut milk(Johnson 1999) The efficiency of extraction ofthe active constituents which is measured bykavalactone extraction into water varies con-siderably (Murray 2000) but is higher fromfresh material than from the dried plant Kavaconsumed in Vanuatu is reputed to be thestrongest anywhere in the South Pacific The is-lands of Tanna and Pentecost are especiallynoted for their potent brews It is thought thatpart of this increase in potency is the result ofpreparing the drink from the raw fresh rootswhereas in Fiji and elsewhere it is made fromdried rootstock (Greenwood-Robinson 1999)
MODERN PREPARATION TECHNIQUES
The bioavailability of kava constituentsvaries substantially depending on the methodof extraction (Hansel et al 1994 [cited in Schulzet al 1997] Loew 2002) Kava is predomi-nantly available in Germany as a so-called con-centrated standardized extract that is designedto maximize extraction of the kavalactones
KAVA WORK-IN-PROGRESS 239
Schulz noted that to create these concentratedstandardized extracts kava is dissolved in ahigh percentage of an ethanolndashwater mixtureto obtain extracts containing approximately30 kavalactones or alternatively using anacetonendashwater mixture to obtain extracts con-taining approximately 70 kavalactones Whit-ton Whitehouse and Evans (Appendix 1)make the same point about enhanced kavalac-tone extraction using a high ethanol or acetonemedium but detail somewhat different extrac-tion values Both types of products have a herb-to-extract ratio of approximately 12ndash201(Schulz 1997) The dosage recommended by theGerman Commission E is expressed as theequivalent of 60ndash120 mg of kavalactones per day(Blumenthal 1998)
The preparation methods used for stan-dardized products are highly technical and extraction rates vary (Kubatova et al 2001)depending on the solvents used and the tem-perature at which the products are preparedAs Whitton et al propose (Appendix 1) bothefficacy and safety may depend on thekavalactones remaining in their natural formsand on the extraction of the other natural con-stituents of the plant
Varying extraction techniques and preparationmethods may result in an unnatural variation inthe relative concentration of each lactone or inproduction artifacts that may be pathologic to theliver It should be noted that some commercialkava products may also contain syntheticracemic kavain that may have other characteris-tics than the naturally occurring product has Itis clear that these technical matters related to ex-traction techniques require further elucidation
Proponents of concentrated standardizedproducts assert that they provide an effectivedose within a consistent range The traditionalwater-based kava preparations of the Polyne-sian peoples and low-alcohol kava tincturesused by herbal practitioners have been consid-ered to be unreliable because the concentrationof active constituents is relatively low andvaries from kava batch to batch Howeverthere are four relevant counterarguments
(1) The whole range of the constituents mayproduce a more effective and safe medicine(Williamson 2001)
(2) Some constituents not necessarily consid-ered active may enhance the safety of themedicine (Appendix 1)
DENHAM ET AL240
OCH3
H3COyangonin
(+)-methysticin
O O
OCH3
demethoxyangonin
O O
OCH3
OO
OH
O
(+)-dihydromethysticin
OCH3
OO
OH
O
(+)-kavain
OCH3
OH
O
(+)-dihydrokavain
OCH3
OH
O
FIG 1 Kavapyrones of kava (Piper methysticum) Per Haberlein et al 1997
(3) Definitive isolation of the active constituentis elusive in other medicinal plants such asHypericum perforatum (McIntyre 2000Barnes et al 2001)
(4) Herbal practitioners rely on the synergy be-tween a whole range of constituents in theherb or herb within a herbal prescriptionwhich is individually prescribed for a pa-tient This positive interaction may alsohave the benefit of keeping levels of anyone constituent below the safety threshold
LOW-ALCOHOL TINCTURES
The Traditional Medicines Evaluation Com-mittee (TMEC) strongly advocates the use ofextraction techniques that closely approximatethose traditionally used in Polynesia Thiswould require the use of low-alcohol tincturesmade by the traditional cold macerationprocesses common to UK tincture makingThe reasons for this opinion are set out belowthey have also been explored by Whitton et al(Appendix 1)
Tinctures used by herbal practitioners areprepared by macerating dried kava in a mix-ture of water and ethanol It has been shownthat such extracts using 25 ethanol75 wa-ter contain up to 30 times fewer kavalactonesthan the concentrated standardized prepara-tions (Appendix 1) The traditional preparationmethod using a mixture of 25 ethanol75water extracts a wider range of the naturalkava constituents (Appendix 1)
DOSAGE AND OVERDOSAGE
Assuming a 15 25 tincture and an upperlimit of 20 kavalactones in the dried herb(concentrations stated as 3ndash20 see sectionon Pharmacology below) then 500 mL of theherb would contain (100 3 02 3 015) 5 3 g(3000 mg) of kavalactones In addition assum-ing a daily dosage of 5ndash10 mL of the 15 25tincture the daily dose of kavalactonesamounts to a maximum of 30ndash60 mg If the con-centration of kavalactones were lower for ex-ample at approximately 10 as appears to bethe case with regard to Australian kava dis-
cussed by Clough et al (2000) then this dosagefalls to 15ndash30 mg per day It is noteworthy thatthe maximum daily dosage here is equivalentto the minimum daily dosages of the 60ndash210mg kavalactones given in clinical trials of kavaconducted in Germany
Although standardized extracts provide ahigher dosage of kavalactones than low-alco-hol tinctures overdosage in itself is unlikelyto be the cause of hepatotoxicity Strong evi-dence for this is the fact that kava is takendaily at high doses as a normal part of dailylife in large areas of the South Pacific Indeedsome of the accounts of high kava intake areremarkable For example Chanwai (2000) de-scribed the case of a man who was admittedto a hospital after an overdose but ldquoslept offrdquohis symptoms and admitted to consuming upto 40 bowls of a kava preparation per day forthe last 14 years In Australia missionaries in-troduced kava to the aborigines in the 1980sas a substitute for alcohol and it is claimed thatthis has led to abuse of kava Clough et al(2000) discussed this concern and reviewedtwelve studies on the amount of kava usedThe researchers found that social setting ap-pears to determine the amount used with lonedrinkers consuming much more than peoplewho enjoy kava in a family group The re-searchers described normal use of kava in theNorthern Territory as being 37 g of kava pow-der (containing approximately 3800 mg ofkavalactones) per hour with heavy consumersusing approximately 610 g per week preparedas a drink The incidence of serious illness re-sulting from hepatotoxicity associated withregular kava usage would surely have beenobserved by the medical services in Polynesiaand Australia if overdosage of kavalactoneswere the main cause of hepatotoxicity
UNTOWARD EFFECTS
There is a justified concern in Europe thatidiosyncratic hepatotoxicity associated with us-ing some herbal medicines may not be identi-fied because the population that takes herbalmedicines is not large enough to produce suf-ficient cases for the association to be noted Butthe fact that kava remains in traditional usageto such a wide extent is a powerful argument
KAVA WORK-IN-PROGRESS 241
that idiosyncratic hepatotoxicity would havebeen noted
Two postmarketing observation studies inGermany each on more than 3000 people werecited by Pittler and Ernst (2000) in addition tothe abovementioned clinical trials In these ob-servational studies the rate of adverse eventswas 23 (with a daily dose of 120ndash240 mg ofkavalactones) and 15 (with a daily dose of105 mg of kavalactones) The most frequent ad-verse reports were gastrointestinal complaintsallergic skin reactions headaches and photo-sensitivity
There is evidence in the South Pacific of a char-acteristic kava-induced skin disease a scaly rashthat is suggestive of icthyosismdasha condition calledldquokava dermopathyrdquo (Ruze 1990) Although theskin becomes yellow the description does notsuggest an underlying hepatic condition in thatthe patient remains well the rash is not itchyand the condition is ameliorated without treat-ment if heavy use of kava is reduced
The German and Swiss reports cited by theBfArM are of concern because there have beenprevious reports of hepatotoxicity associatedwith the use of some medicinal plants (Larrey1997) The kava case reports from the BfArM(see Appendix 2) include all three of the mainforms of acute damage that can result from ad-verse drug reactions (1) necrosis (2) drug-in-duced hepatitis and (3) cholestatic hepatitis(Hodgson and Levi 1997) This suggests thatthere is a range of causes rather than just onecause in these cases The BfArM case reportshave been circulated worldwide and are cur-rently being evaluated by government agenciesin Europe Australia Canada the UnitedStates and elsewhere We have received anumber of informal case assessments fromthese sources that cannot be specifically citedbecause of their confidential status To achievetransparency and encourage a full debate aboutkava however the BfArM cases are evaluatedin the section entitled Discussion of Cases Re-ported by the BfArM
CRITERIA FOR ASSESSING THE CASE REPORTS
A recent review of the information availableon the case reports (Schmidt and Nahrstedt
2002) is supported by details of the case re-ports on the Web site of the University ofMuenster (wwwuni-muensterdechemiepbkavaanalysehtml)
The criteria for causality assessment of ad-verse reactions used are as follows (Edwardsand Aronson 2000)Probable is defined as
A clinical event including a laboratory testabnormality that occurs in a plausible timerelation to drug administration and that can-not be explained by coincidental or concur-rent disease or other drugs or chemicals
The response to withdrawal of the drug(dechallange) should be clinically plausible
The event must be definitive pharmacolog-ically or phenomenologically using a satis-factory rechallenge procedure if necessary
Possible is defined as
A clinical event including a laboratory testabnormality with a reasonable time relationto administration of the drug but that couldbe explained by concurrent disease or otherdrugs or chemicals
Information on drug withdrawal may belacking or unclear
Unlikely is defined as
A clinical event including a laboratory testabnormality with a temporal relation to theadministration of the drug which makes acausal relation improbable and in whichother drugs chemicals or underlying dis-ease provide plausible explanations
Unassessable is defined as
A report suggesting an adverse reaction thatcannot be judged because information is in-sufficient or contradictory and cannot besupplemented or verified
DISCUSSION OF CASES REPORTED BY THE BfArM
The cases discussed below are analyzed andcategorized by common factors of note withour own assessments
DENHAM ET AL242
(1) Cases of most concern
This group includes five cases 10 13 16 18and 28 According to the assessments made by various government agencies these casescause the most concern and are often cited asbeing probable For this reason these cases aredealt with first As discussed below mostmdashifnot allmdashof these cases have associated factorsthat put this probable categorization into ques-tion
Case 10 This case described necrotizing hep-atitis in a 39-year old female patient with pos-itive reexposure (Strahl et al 1998) During thefirst period that the kava product was takenan oral contraceptive and paroxetine were con-comitant medications It appears that paroxe-tine was not the only antidepressant taken bythis patient who also occasionally took StJohnrsquos wort (Hypericum perforatum) The Exec-utive Summary issued by the Bundesverbandder Arzneimittel Hersteller eV (BAH) andBundesverband der Pharmazeutischen Indus-trie eV (BP) (see Appendix 3) stated ldquoA causalrelationship with kava cannot be excluded butthe patientrsquos history and a potential preexistingliver damage must be taken into account In ad-dition the kava preparation used was not iden-tified by the physicianrdquo
Moreover in this case taking paroxetine incombination with an oral contraceptive maywell have led to overburdening the liver a sit-uation that could have been exacerbated by tak-ing a kava preparation Schmidt and Nahrstedt(2002) suggested that this case may be associ-ated with an immunologic reaction After re-viewing all of the cases in detail Schmidt andNahrstedt (2002) concluded that this is the onlycase for which there was sufficient informationto make an association with kava appear prob-able and for which the dose of kava also con-formed to that recommended by the Com-mission E monograph (Blumenthal 2000)However as discussed below Russmann et al(2001) tested this patient for CYP2D6 and as inCase 16 found this patient to be CYP2D6 defi-cient which appears to have made her partic-ularly vulnerable to the cocktail of drugs shewas taking Given the complicating features ofthis case we submit that this case should beclassed as possible rather than probable
Case 13 This was a case of a 62-year-oldwoman with jaundice The BfArM table (seeAppendix 2) noted regarding concomitantmedication that there was ldquonone denotedrdquo butit was claimed that concomitant medication didexist but was ldquounknownrdquo The insufficiency ofdata provided for this case was highlighted byBfArMrsquos warning note ldquoNo medical messagerdquoIn addition it should be noted that no detailsof the dosage of kava or period of its adminis-tration were apparently recorded for this caseThis is clearly insufficient information onwhich to base a probable assessment
Case 16 This case concerned a 33-year-oldwoman with jaundice The woman wasrecorded as having taken an overdose of alco-hol measured at 60 g (Russman et al 2001) andthen analgesics including paracetamol fol-lowing this alcohol binge Despite the massiveintake of alcohol a liver biopsy indicated thata drug rather than an alcohol induced toxicgenesis However this case like that of Case 10above was discussed by Russman et al (2001)who demonstrated afterward that this patientwas shown to be CYP2D6 deficient which (asdiscussed below) seems to be a risk factor forthe hepatotoxicity that was ascribed to kavaWe submit that given these circumstances thiscase should be considered possible rather thanprobable
Case 18 This case concerned a 50-year-oldman who had necrosis leading to a liver trans-plant This patient took a product manufac-tured by acetone extraction at a dose deliver-ing 210ndash280 mg of kavalactones per day for 15months ldquomoderate alcoholrdquo (ldquomoderaterdquo is notdefined by BfArM) evening primrose(Oenothera biennis) and a yeast preparationThe dosage of kava was well above the Ger-man Commission E recommended dose ofkavalactones (Blumenthal 1998) It was alsorecorded that 500ndash1000 mg of paracetamol wastaken by this patient shortly before transplan-tation The combination of paracetamol and al-cohol plus the very high dose of kava extractedin acetone taken by this man casts seriousdoubts on the assessment of probable in thiscase
Case 28 (BAH) This case concerned a
KAVA WORK-IN-PROGRESS 243
woman age unknown with hepatitis This caseis hard to assess because neither the patientrsquosage nor diagnosis was given and the womanwas taking eleven medications including estra-diol valerate acetylcysteine losartan (which israrely be associated with hepatitis) and mepra-zole (which can be associated with liver diseasealthough this is rare) Omeprazole is metabo-lized by the polymorphic CYP2C19 which is absent in 3 of Caucasians (Flockhart et al2000) The woman was also taking echinacea(Echinacea purpurea) and five products that ap-peared to be for upper respiratory problems Itshould be noted that this patient was taking syn-thetic kavain not kava A comment from BfArMconcerning this case noted ldquorecurrence of the he-patic side-effectsrdquo which has evidently been in-terpreted by some authorities as being equiva-lent to a ldquopositive rechallengerdquo Whether or notthis was actually so was not clear from the datasupplied It appears (Schmidt and Nahrstedt2002) that Case 28 has been published as twocases with slightly different details This is con-fusing and considering that the woman was tak-ing 11 other medications together with a syn-thetic kava (which we submit is not equivalentto natural kava) and that no diagnosis of hercondition was supplied this calls the assessmentof probable in this case into question
(2) Cases associated with taking synthetic kavain
In this category there were 4 cases 1 2 19and 28
In each of these cases the patients concernedwere taking a product made from synthetickavain Although the outcome was hepatitis inall four cases kavain cannot be equated withthe naturally occurring form of kava whichcontains many other constituents that may playan important role in ensuring the safety of thisherb Therefore we submit that no inferenceshould be drawn from these cases Traditionalusage should not be taken as evidence for safeusage of synthetic products
(3) Patients who were taking oral contraceptivepills or hormone replacement therapy (HRT)together with drugs that can also be associatedwith liver damage
The cases in this category were 4 10 12 2021 and 28
Cholestatic jaundice associated with use ofestrogen-containing medications is extremelyrare (Lindberg 1992) but does occur In these6 cases the women were also taking drugs thatcan also be associated with jaundice
Case 4 This case involved a 39-year-oldwoman with jaundice She was on diazepam10 mg PRN for 6 months Some authoritiescalled this case possible Our assessment is thatthe case is unassessable
Case 10 This case involved a 39-year-oldwoman with necrotizing hepatitis For a de-tailed assessment see above
Case 12 This case involved a 37-year-oldwoman with hepatitis She was on 150 mg ofdiclofenac via intramuscular injection Hepato-toxic reactions associated with nonsteroidalanti-inflammatory drug use are extremely rareand concomitant exposure to other hepatotoxicdrugs is considered to be an important factor(Bareille et al 2001) This case of hepatitis isdifficult to interpret because it occurred inBrazil and because ldquoreexposure was said to benegative for all three drugsrdquo We regard thiscase as unassessable
Case 20 This case involved 50-year-oldwoman with necrosis who had a liver trans-plant She had a 20-year history of combinedoral contraceptive use but had changed monthsearlier to estradiol valerate (which was appar-ently taken alone) as HRT She had also startedglimepiride 8 months earlier This is used fortreating type II diabetes and is rarely associatedwith cholestatic jaundice and liver failure Weregard this case as unlikely
Case 21 This case involved a 22-year-oldwoman with necrosis who had a liver trans-plant This woman had changed from Valette(Jenapharm GmbH Jena Germany) (2 mg ofdienogest and 003 mg of ethinlestradiol) toPramino (180215250 mcg of norgestimateand mcg 25 of ethinylestradiol) She also tookrizatriptan if required for migraine reliefRizatriptan should be used with caution in he-patic impairment and avoided if a patient hassevere liver disease Some authorities considerthis case as being possible but our assessment
DENHAM ET AL244
is in view of the other medications taken isthat this case is unassessable
Case 28 This case involved a woman age un-known with hepatitis This case is discussed atlength above As noted above this patient wastaking synthetic kavain not kava
(4) Patients who were taking drugs that can beassociated with liver damage
There were ten cases in this category 1 6 914 15 17 19 23 2627 and 29
Case 1 This case involved a woman age 69with cholestatic hepatitis She was taking pen-toxifylline (which can be associated with intra-hepatic cholestasis) and a diuretic including thepotassium-sparing triamterene (which can beassociated with jaundice) As noted above thispatient was taking synthetic kavain not kavaWe consider this case unassessable
Case 6 This case involved a woman age 50with hepatitis She was taking frusemide(which can be associated with cholestatic jaun-dice) triamterene atenolol and a large dose ofterfenadine (300 mg) The recommended doseof terfenadine in the British National Formu-lary (March 2001) is 60ndash120 mg The Formularyrecommends avoiding this drug in patientswho have hepatic impairment and also says toldquoavoid concomitant administration of drugs li-able to produce electrolyte imbalance such asdiureticsrdquo (British National Formulary 2001)Despite this warning this woman was also tak-ing the diuretic frusemide The InterkantonalenKontrollstelle der Schweiz of Switzerland con-sidered this case of hepatitis to be caused byterfenadine And although some authoritiesregard this case as possible our assessment isthat this case is unlikely
Case 9 This case involved an 81-year-oldwoman who had liver failure and subsequentdeath She was taking hydrochlorothiazide(which can occasionally be associated with in-trahepatic cholestasis) However according toSchmidt and Nahrstedt (2002) there was evi-dence of chronic alcohol abuse and they re-ported that the autopsy showed chronic pan-creatitis that was characteristic of alcoholabuse The autopsy report (Schmidt and
Nahrstedt 2002) apparently said that thesymptoms must have occurred over a periodof at least 18 months The report conceded thatldquohepatic impairment by alcohol [was] not ex-cludedrdquo In these circumstances it seems en-tirely reasonable to claim that this case is un-related to kava use We regard this case asunlikely
Case 14 This case involved a 33-year-oldwoman with hepatitis Cisapride may havebeen taken (which can cause reversible changesthat show in liver-function tests) Cirrhosis ina woman of 33 is an unexplained finding andthe detail in this case is inadequate to elucidateit We consider this case to be unassessable
Case 15 This case involved a 46-year-oldwoman with jaundice She had been taking hy-drochlorothiazide (which can be associatedwith intrahepatic cholestasis) for 55 monthsplus 80 mg of valsartan and 80 mg ofpropanolol per day Some authorities regardthis case as possible but we consider it to beunassessable
Case 17 This case involved a 59-year-oldwoman with jaundice She had taken 100ndash200mg of celecoxib a cyclo-oxygenase-2 inhibitorper day According to the criteria for causalityassessment of adverse reactions some author-ities consider this case to be possible but our as-sessment is that it is unassessable
Case 19 This case involved a 21-year-oldwoman with hepatitis She was taking panto-prazole (which as with omeprazole can be as-sociated with liver disease) She was also takingparacetamol and metoclopramide and had over-dosed on kavain More detail is needed on othermedical conditions suffered by this patient in or-der to interpret this case It is suggested bySchmidt that this woman was using up to 10tablets per day of the product (the recom-mended dose is up to 6 tablets per day) and thatthere was apparently a discussion in her med-ical record file that she may also have used Ec-stasy (substance that has been associated with
KAVA WORK-IN-PROGRESS 245
Personal communication from M McGuffin to M McIn-tyre available as an online document at ehpaglobalnetcouk
fulminant hepatic failure) This case appears tobe unassessable
Case 23 This case involved a 35-year-oldwoman with jaundice According to the BfArM(see Appendix 2) this patient also took parac-etamol but no dosage or details were providedThis case and case 25 in the BfArM listing ap-pear to be the same case Both cases have beenlabeled as possible by some authorities butgiven the lack of information about the dosageof paracetamol and the apparent confusion re-garding cases 23 and 25 we submit that theonly logical assessment is unassessable
Case 2627 This case involved a woman whowas either 38 or 39 yearsrsquo old with hepatitis Itappears that the two cases have been duplicated(Schmidt and Nahrstedt 2002) The confusionwith this case is another example of inaccuratedata provided by the BfArM Information re-garding these cases (or case) depending onwhether the two reports concern the samewoman is unclear Penicillin can be associatedwith hypersensitivity and cholestatic jaundicebut the information given is inadequate to makeany meaningful assessment For this reason weclass this case as unassessable
Case 29 This case involved a 60-year-oldwoman who had a liver transplant This womanwas taking piretamide (which is a loop diuretic)Frusemide another loop diuretic can be associ-ated with cholestatic jaundice According to theBfArM chart (see Appendix 2) she was also tak-ing a sympathomimetic drug etilefrin Thedosage of kava varied but was up to 480ndash1200mg per day (Schmidt and Nahrstedt 2002)which is up to ten times the German Commis-sion E maximum recommended dose (Blumen-thal 1998) Although some authorities have re-garded this case as possible in view of themarked overdosing of kava and the concomitantmedication this case can hardly be said to be areflection on the proper therapeutic use of kava
(5) Cases in which drugs not associated withliver damage herbal medicines or dietarysupplements or kavain alone were taken
This category had eight cases 2 78 11 1322 24 and 25
For these cases detail was limited and theBfArM did not implicate any other drugs ormedications (although this may not be thecase)
All patients in this group apart from the pa-tient in Case 78 for whom no information wasgiven were reported to have made full recov-eries In some of these cases it is not clearwhether the patients were ill or whether thesecases merely recorded raised liver-function en-zymes
Case 2 This case involved a 35-year-old manwith cholestatic hepatitis Concomitant med-ication was ldquounknownrdquo Apart from Cases 18and 30 this is the only case for which it is pos-sible that no other concomitant medication wastaken but there is a marked lack of informationfor this case As noted above this patient wastaking synthetic kavain not kava We regardthis case as unassessable
Case 5 This case involved a woman who waseither 68 or 69 yearsrsquo old with cholestatic he-patitis She was also taking a St Johnrsquos wort(Hypericum perforatum) product which hasbeen associated with CYP3A4 A biopsyshowed ldquoimmunologic hypersensitivityrdquo Thiscase may be regarded as possible but in viewof the immunologic hypersensitivity it maywell have been an idiosyncratic event that wasnot necessarily associated with kava usage
Case 78 This case involved a woman or twowomen ages 72 andor 75 with cholestatic he-patitis These two cases appear to be actuallyone case The woman was taking twoherbalvitamin products one of which in-cluded 06 mg of kavalactones Given the con-fusion involved these ldquocasesrdquo must be re-garded as unassessable
Case 11 This case involved a 59-year-oldwoman who was taking hyoscine butylbro-mide as a suppository Schmidt and Nahrstedt(2002) commented that according to additionalinformation obtained from the BfArM it is un-certain as to whether this patient was taking akava product at all We regard this case asunassessable
DENHAM ET AL246
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
SPECIAL REPORT
THE JOURNAL OF ALTERNATIVE AND COMPLEMENTARY MEDICINEVolume 8 Number 3 2002 pp 237ndash263copy Mary Ann Liebert Inc
Kavamdashthe Unfolding Story Report on a Work-in-Progress
ALISON DENHAM BA (Soc) MNIMH1
MICHAEL McINTYRE MA FNIMH FRCHM MBAcC2
and JULIE WHITEHOUSE PhD MNIMH3
ABSTRACT
This paper originated as a submission (now updated) to the UK Medicines Control Agencyand Committee of Safety of Medicines (CSM) on January 11 2002 in response to a report circu-lated by the German Federal Institute for Drugs and Medical Products (German initials are BfArM)a compilation of which is summarized in Appendix 2 This agency issued notification in late No-vember 2001 of some thirty adverse events associated with the use of concentrated standardizedpreparations of kava (Piper methysticum Forst f) reported from Germany and Switzerland Ananalysis of the summary of the BfArM case reports (see Appendix 2) shows that these contain du-plications among the cases cited The original submission that was sent to the CSM January 2002has been updated to the version published here This new version was completed in April 2002
As a result of the alert from BfArM the evaluation of kavarsquos safety is now occurring on aworldwide basis and being that this a matter of considerable importance to the public the healthcare community and regulatory authorities as well as to kava farmers throughout Polynesia itis it important to depict this progress report As such this updated report does not provide fi-nal answers The material released by the BfArM is lacking in detail however it is hoped thatthis report will shed light on the kava controversy It is anticipated that there will be further up-dates shortly
This report prepared on behalf of the Traditional Medicines Evaluation Committee a subcom-mittee of the European Herbal Practitioners Association argues that many of the adverse eventscited by the BfArM should not be attributed to kava In addition the report states that the prop-erties of concentrated standardized kava extractsmdashas opposed to preparations that closely ap-proximate those created for traditional usemdashcontribute to causing adverse events This report pro-poses a number of simple measures that will ensure that safe kava preparations may continue tobe available in the United Kingdom
237
BENEFITS OF KAVA
Kava (Piper methysticum Forst f) is an im-portant herbal medicine with unique
properties The ability of herbal practitioners to
care for their patients would be significantly af-fected if this herbrsquos use were restricted or cur-tailed so that practitioners were unable to pre-scribe it Since the early 1900s kava has beenused in Britain by herbal practitioners mainly
1University of Central Lancashire Preston United Kingdom2Midsummer Cottage Clinic Oxon United Kingdom3University of Westminster London United Kingdom
for urinary problems (Ellingwood 1919) Theindications given in the British Herbal Pharma-copoeia (Anonymous 1983) are ldquoCystitis Ure-thritis Rheumatism and Infection of the gen-ito-urinary tractrdquo More recent texts emphasizethe herbrsquos usage as a nervine For example in-dications given by Mills and Bone (2000) areldquoanxiety of nervous origin nervous tensionrestlessness or mild depression of non-psy-chotic origin menopausal symptoms and in-flammation and infections of the genitourinarytracts of both men and women muscular andnervous pain and insomniardquo Kava use as anervine (which is its traditional therapeuticuse) has increased markedly in recent yearspartly because of the evidence for clinical effec-tiveness found in clinical trials (Pittler and Ernst2000) However it is interesting to note thatsuch usage is not completely new Felter (1905)notes kavarsquos application inter alia for treatingneuralgia dizziness and despondency Theherb has a particular value for treating agita-tion and anxiety (Spinella 2001) when othernervines have proved to be ineffective
Clinical trials have been reviewed recentlyby Pittler and Ernst (2000) who stated that for treating anxiety kavarsquos superiority overplacebo was suggested by all seven trials un-der review and that for the three trials in-cluded in the meta-analysis there was a sig-nificant reduction in score on the HamiltonAnxiety Scale The clinical trials were all car-ried out in Germany where kava is prescribedby physicians and sold over the counter inpharmacies for treating anxiety and insomniaA recent review (Loew 2002) listed nine dou-ble-blinded randomized controlled trials in-volving 808 patients and stated that kava wassignificantly superior to placebo for treatingsymptoms associated with anxiety These trialsused a range of products standardized on15ndash70 kavalactones providing a dailydosage of 60ndash210 mg per day of kavalactonesThe use of kava is being increasingly advocatedas an alternative to benzodiazepines for treat-ing anxiety and has been tested in at least onetrial (Loew 2002) The trial was 28 days longand involved 61 people And for example DeLeo et al (2001) showed a significant relativedecrease in anxiety in a double-blinded ran-domized trial on 40 menopausal women when
kava was combined with hormone replacementtherapy This trial lasted for 6 months and thedosage of kava extract was 100 mg per day (con-taining 55 mg of kavain) It has been claimed thatthe German Federal Institute for Drugs and Med-ical Products (German initials are BfArM) citeddoubts about kavarsquos efficacy for treating anxietyas one reason for starting an investigation on theherb (Anonymous 2001) Surprise was ex-pressed in Germany for this reason because itwas claimed (Anonymous 2001) that a recentrandomized controlled trial awaiting publicationhad demonstrated kavarsquos efficacy for this use atdoses that conform to the Commission E mono-graph on the herb (Blumenthal 2000)
The modern use of kava as a nervine is in ac-cordance with its traditional usage in the SouthPacific Kava drinkers report a sense of relax-ation and tranquillity and manifest a sociableattitude (Chanwai 2000) The herb is used as asocial and ceremonial drink among men inPolynesia In modern times as the influence ofthe Christian missionaries decreases kavarsquosuse has become more widespread and fre-quent For instance Kava is an important partof social life in Fiji Fijian spiritual leaders arecalled dauvaguna the literal translation ofwhich means ldquoexpert at drinking kavardquo(Greenwood-Robinson 1999) Kava is not ad-dictive and does not seem to produce the vio-lent antisocial effects that alcohol produces(Lebot et al 1997) However there are seriousconcerns in Australia (Clough et al 2000)about the herbrsquos abuse as a recreational drugwhen it is used to excess It has been associatedwith inactivity confusional states and generalill-health possibly as a result of associated mal-nutrition caused by irregular eating habits(Chanwai 2000) In Aboriginal communitiesmalnutrition is not uncommon and this associ-ation is considered to be unproven
WHAT IS KAVA
Root bark and root of kava are used eitherfresh or dried for its preparation
Based on an archaeological study of charac-teristic drinking bowls it has been proposedthat the herb was first domesticated in Polyne-sia more than 2000 years ago (Green 1974 [cited
DENHAM ET AL238
in Lebot et al 1997]) A comprehensive surveyby Lebot and Levesque in 1989 (cited in Lebotet al 1997) suggests that kava was originallydomesticated in the Vanuatu islands
Kava is now obtained from a wide range ofcultivars in the South Pacific The plant is al-ways propagated vegetatively from stem cut-tings as it does not reproduce via fertilizationmethods There are many cultivars and newstrains continue to be developed by Polynesianfarmers because each strain is considered tohave different psychoactive effects
In recent years there has been increasingpressure on the market because of the increasedworldwide demand for kava In 1998 it wasamong the top-selling herbs in the UnitedStates with a turnover of $8 million repre-senting a growth rate of 473 (Pittler and Ernst2000) It is possible that the current hepatotox-ity problems are to some extent a consequenceof poor quality control caused by a rapid andextraordinary increase in the size of the market(Murray 2000)
There are also concerns that intensive culti-vation and harvesting may affect the quality ofthe product (Aarlbersberg 1999) However be-ing that a range of products is implicated thisis unlikely to provide a satisfactory explanationfor all the reported adverse reactions It ishoped that the BfArM will release relevant dataabout the source and quality assurance of thekava supply in due course
KAVA PHARMACOLOGY
Kava is a well-researched herb The crys-talline resin was first isolated in 1857 by aFrench naval pharmacist and a detailed mono-graph was published in 1886 (Lewin 1886[cited by Lebot et al 1997]) The kavalactonesare considered to be the active constituents andhave been shown in animal studies to have asedative action (Hansel 1996) although themechanism is unclear (Spinella 2001) Thekavalactones are found in the resinous portion(5ndash9) of the plant material and are poorlysoluble in water
Kavalactones are 4-methoxy-2-pyrones withphenyl or styryl substituents at the 6th position(Lebot et al 1997) Total kavalactone content
varies from 3 to 20 dry weight Eighteen lac-tones have so far been isolated (He et al 1997)with the following six compounds (includingfour chiral enantiomers and two achiral enan-tiomers) being considered most important(Haberlain 1997 see Fig 1)
Chiral enantiomers(1) (1)-kavain(2) (1)-dihydrokavain(3) (1)-methysticin(4) (1)-dihydromethysticin
Achiral enantiomers(5) yangonin(6) demethoxyangonin
TRADITIONAL PREPARATION TECHNIQUES
Kava is traditionally prepared in the SouthPacific by grinding and mixing the root or rootbark with cold water This makes an emulsionthat is a suspension of the resinous constituentsin water (Lebot et al 1997) The herb is alsoprepared as an emulsion (also traditionallyprepared without heating) in coconut milk(Johnson 1999) The efficiency of extraction ofthe active constituents which is measured bykavalactone extraction into water varies con-siderably (Murray 2000) but is higher fromfresh material than from the dried plant Kavaconsumed in Vanuatu is reputed to be thestrongest anywhere in the South Pacific The is-lands of Tanna and Pentecost are especiallynoted for their potent brews It is thought thatpart of this increase in potency is the result ofpreparing the drink from the raw fresh rootswhereas in Fiji and elsewhere it is made fromdried rootstock (Greenwood-Robinson 1999)
MODERN PREPARATION TECHNIQUES
The bioavailability of kava constituentsvaries substantially depending on the methodof extraction (Hansel et al 1994 [cited in Schulzet al 1997] Loew 2002) Kava is predomi-nantly available in Germany as a so-called con-centrated standardized extract that is designedto maximize extraction of the kavalactones
KAVA WORK-IN-PROGRESS 239
Schulz noted that to create these concentratedstandardized extracts kava is dissolved in ahigh percentage of an ethanolndashwater mixtureto obtain extracts containing approximately30 kavalactones or alternatively using anacetonendashwater mixture to obtain extracts con-taining approximately 70 kavalactones Whit-ton Whitehouse and Evans (Appendix 1)make the same point about enhanced kavalac-tone extraction using a high ethanol or acetonemedium but detail somewhat different extrac-tion values Both types of products have a herb-to-extract ratio of approximately 12ndash201(Schulz 1997) The dosage recommended by theGerman Commission E is expressed as theequivalent of 60ndash120 mg of kavalactones per day(Blumenthal 1998)
The preparation methods used for stan-dardized products are highly technical and extraction rates vary (Kubatova et al 2001)depending on the solvents used and the tem-perature at which the products are preparedAs Whitton et al propose (Appendix 1) bothefficacy and safety may depend on thekavalactones remaining in their natural formsand on the extraction of the other natural con-stituents of the plant
Varying extraction techniques and preparationmethods may result in an unnatural variation inthe relative concentration of each lactone or inproduction artifacts that may be pathologic to theliver It should be noted that some commercialkava products may also contain syntheticracemic kavain that may have other characteris-tics than the naturally occurring product has Itis clear that these technical matters related to ex-traction techniques require further elucidation
Proponents of concentrated standardizedproducts assert that they provide an effectivedose within a consistent range The traditionalwater-based kava preparations of the Polyne-sian peoples and low-alcohol kava tincturesused by herbal practitioners have been consid-ered to be unreliable because the concentrationof active constituents is relatively low andvaries from kava batch to batch Howeverthere are four relevant counterarguments
(1) The whole range of the constituents mayproduce a more effective and safe medicine(Williamson 2001)
(2) Some constituents not necessarily consid-ered active may enhance the safety of themedicine (Appendix 1)
DENHAM ET AL240
OCH3
H3COyangonin
(+)-methysticin
O O
OCH3
demethoxyangonin
O O
OCH3
OO
OH
O
(+)-dihydromethysticin
OCH3
OO
OH
O
(+)-kavain
OCH3
OH
O
(+)-dihydrokavain
OCH3
OH
O
FIG 1 Kavapyrones of kava (Piper methysticum) Per Haberlein et al 1997
(3) Definitive isolation of the active constituentis elusive in other medicinal plants such asHypericum perforatum (McIntyre 2000Barnes et al 2001)
(4) Herbal practitioners rely on the synergy be-tween a whole range of constituents in theherb or herb within a herbal prescriptionwhich is individually prescribed for a pa-tient This positive interaction may alsohave the benefit of keeping levels of anyone constituent below the safety threshold
LOW-ALCOHOL TINCTURES
The Traditional Medicines Evaluation Com-mittee (TMEC) strongly advocates the use ofextraction techniques that closely approximatethose traditionally used in Polynesia Thiswould require the use of low-alcohol tincturesmade by the traditional cold macerationprocesses common to UK tincture makingThe reasons for this opinion are set out belowthey have also been explored by Whitton et al(Appendix 1)
Tinctures used by herbal practitioners areprepared by macerating dried kava in a mix-ture of water and ethanol It has been shownthat such extracts using 25 ethanol75 wa-ter contain up to 30 times fewer kavalactonesthan the concentrated standardized prepara-tions (Appendix 1) The traditional preparationmethod using a mixture of 25 ethanol75water extracts a wider range of the naturalkava constituents (Appendix 1)
DOSAGE AND OVERDOSAGE
Assuming a 15 25 tincture and an upperlimit of 20 kavalactones in the dried herb(concentrations stated as 3ndash20 see sectionon Pharmacology below) then 500 mL of theherb would contain (100 3 02 3 015) 5 3 g(3000 mg) of kavalactones In addition assum-ing a daily dosage of 5ndash10 mL of the 15 25tincture the daily dose of kavalactonesamounts to a maximum of 30ndash60 mg If the con-centration of kavalactones were lower for ex-ample at approximately 10 as appears to bethe case with regard to Australian kava dis-
cussed by Clough et al (2000) then this dosagefalls to 15ndash30 mg per day It is noteworthy thatthe maximum daily dosage here is equivalentto the minimum daily dosages of the 60ndash210mg kavalactones given in clinical trials of kavaconducted in Germany
Although standardized extracts provide ahigher dosage of kavalactones than low-alco-hol tinctures overdosage in itself is unlikelyto be the cause of hepatotoxicity Strong evi-dence for this is the fact that kava is takendaily at high doses as a normal part of dailylife in large areas of the South Pacific Indeedsome of the accounts of high kava intake areremarkable For example Chanwai (2000) de-scribed the case of a man who was admittedto a hospital after an overdose but ldquoslept offrdquohis symptoms and admitted to consuming upto 40 bowls of a kava preparation per day forthe last 14 years In Australia missionaries in-troduced kava to the aborigines in the 1980sas a substitute for alcohol and it is claimed thatthis has led to abuse of kava Clough et al(2000) discussed this concern and reviewedtwelve studies on the amount of kava usedThe researchers found that social setting ap-pears to determine the amount used with lonedrinkers consuming much more than peoplewho enjoy kava in a family group The re-searchers described normal use of kava in theNorthern Territory as being 37 g of kava pow-der (containing approximately 3800 mg ofkavalactones) per hour with heavy consumersusing approximately 610 g per week preparedas a drink The incidence of serious illness re-sulting from hepatotoxicity associated withregular kava usage would surely have beenobserved by the medical services in Polynesiaand Australia if overdosage of kavalactoneswere the main cause of hepatotoxicity
UNTOWARD EFFECTS
There is a justified concern in Europe thatidiosyncratic hepatotoxicity associated with us-ing some herbal medicines may not be identi-fied because the population that takes herbalmedicines is not large enough to produce suf-ficient cases for the association to be noted Butthe fact that kava remains in traditional usageto such a wide extent is a powerful argument
KAVA WORK-IN-PROGRESS 241
that idiosyncratic hepatotoxicity would havebeen noted
Two postmarketing observation studies inGermany each on more than 3000 people werecited by Pittler and Ernst (2000) in addition tothe abovementioned clinical trials In these ob-servational studies the rate of adverse eventswas 23 (with a daily dose of 120ndash240 mg ofkavalactones) and 15 (with a daily dose of105 mg of kavalactones) The most frequent ad-verse reports were gastrointestinal complaintsallergic skin reactions headaches and photo-sensitivity
There is evidence in the South Pacific of a char-acteristic kava-induced skin disease a scaly rashthat is suggestive of icthyosismdasha condition calledldquokava dermopathyrdquo (Ruze 1990) Although theskin becomes yellow the description does notsuggest an underlying hepatic condition in thatthe patient remains well the rash is not itchyand the condition is ameliorated without treat-ment if heavy use of kava is reduced
The German and Swiss reports cited by theBfArM are of concern because there have beenprevious reports of hepatotoxicity associatedwith the use of some medicinal plants (Larrey1997) The kava case reports from the BfArM(see Appendix 2) include all three of the mainforms of acute damage that can result from ad-verse drug reactions (1) necrosis (2) drug-in-duced hepatitis and (3) cholestatic hepatitis(Hodgson and Levi 1997) This suggests thatthere is a range of causes rather than just onecause in these cases The BfArM case reportshave been circulated worldwide and are cur-rently being evaluated by government agenciesin Europe Australia Canada the UnitedStates and elsewhere We have received anumber of informal case assessments fromthese sources that cannot be specifically citedbecause of their confidential status To achievetransparency and encourage a full debate aboutkava however the BfArM cases are evaluatedin the section entitled Discussion of Cases Re-ported by the BfArM
CRITERIA FOR ASSESSING THE CASE REPORTS
A recent review of the information availableon the case reports (Schmidt and Nahrstedt
2002) is supported by details of the case re-ports on the Web site of the University ofMuenster (wwwuni-muensterdechemiepbkavaanalysehtml)
The criteria for causality assessment of ad-verse reactions used are as follows (Edwardsand Aronson 2000)Probable is defined as
A clinical event including a laboratory testabnormality that occurs in a plausible timerelation to drug administration and that can-not be explained by coincidental or concur-rent disease or other drugs or chemicals
The response to withdrawal of the drug(dechallange) should be clinically plausible
The event must be definitive pharmacolog-ically or phenomenologically using a satis-factory rechallenge procedure if necessary
Possible is defined as
A clinical event including a laboratory testabnormality with a reasonable time relationto administration of the drug but that couldbe explained by concurrent disease or otherdrugs or chemicals
Information on drug withdrawal may belacking or unclear
Unlikely is defined as
A clinical event including a laboratory testabnormality with a temporal relation to theadministration of the drug which makes acausal relation improbable and in whichother drugs chemicals or underlying dis-ease provide plausible explanations
Unassessable is defined as
A report suggesting an adverse reaction thatcannot be judged because information is in-sufficient or contradictory and cannot besupplemented or verified
DISCUSSION OF CASES REPORTED BY THE BfArM
The cases discussed below are analyzed andcategorized by common factors of note withour own assessments
DENHAM ET AL242
(1) Cases of most concern
This group includes five cases 10 13 16 18and 28 According to the assessments made by various government agencies these casescause the most concern and are often cited asbeing probable For this reason these cases aredealt with first As discussed below mostmdashifnot allmdashof these cases have associated factorsthat put this probable categorization into ques-tion
Case 10 This case described necrotizing hep-atitis in a 39-year old female patient with pos-itive reexposure (Strahl et al 1998) During thefirst period that the kava product was takenan oral contraceptive and paroxetine were con-comitant medications It appears that paroxe-tine was not the only antidepressant taken bythis patient who also occasionally took StJohnrsquos wort (Hypericum perforatum) The Exec-utive Summary issued by the Bundesverbandder Arzneimittel Hersteller eV (BAH) andBundesverband der Pharmazeutischen Indus-trie eV (BP) (see Appendix 3) stated ldquoA causalrelationship with kava cannot be excluded butthe patientrsquos history and a potential preexistingliver damage must be taken into account In ad-dition the kava preparation used was not iden-tified by the physicianrdquo
Moreover in this case taking paroxetine incombination with an oral contraceptive maywell have led to overburdening the liver a sit-uation that could have been exacerbated by tak-ing a kava preparation Schmidt and Nahrstedt(2002) suggested that this case may be associ-ated with an immunologic reaction After re-viewing all of the cases in detail Schmidt andNahrstedt (2002) concluded that this is the onlycase for which there was sufficient informationto make an association with kava appear prob-able and for which the dose of kava also con-formed to that recommended by the Com-mission E monograph (Blumenthal 2000)However as discussed below Russmann et al(2001) tested this patient for CYP2D6 and as inCase 16 found this patient to be CYP2D6 defi-cient which appears to have made her partic-ularly vulnerable to the cocktail of drugs shewas taking Given the complicating features ofthis case we submit that this case should beclassed as possible rather than probable
Case 13 This was a case of a 62-year-oldwoman with jaundice The BfArM table (seeAppendix 2) noted regarding concomitantmedication that there was ldquonone denotedrdquo butit was claimed that concomitant medication didexist but was ldquounknownrdquo The insufficiency ofdata provided for this case was highlighted byBfArMrsquos warning note ldquoNo medical messagerdquoIn addition it should be noted that no detailsof the dosage of kava or period of its adminis-tration were apparently recorded for this caseThis is clearly insufficient information onwhich to base a probable assessment
Case 16 This case concerned a 33-year-oldwoman with jaundice The woman wasrecorded as having taken an overdose of alco-hol measured at 60 g (Russman et al 2001) andthen analgesics including paracetamol fol-lowing this alcohol binge Despite the massiveintake of alcohol a liver biopsy indicated thata drug rather than an alcohol induced toxicgenesis However this case like that of Case 10above was discussed by Russman et al (2001)who demonstrated afterward that this patientwas shown to be CYP2D6 deficient which (asdiscussed below) seems to be a risk factor forthe hepatotoxicity that was ascribed to kavaWe submit that given these circumstances thiscase should be considered possible rather thanprobable
Case 18 This case concerned a 50-year-oldman who had necrosis leading to a liver trans-plant This patient took a product manufac-tured by acetone extraction at a dose deliver-ing 210ndash280 mg of kavalactones per day for 15months ldquomoderate alcoholrdquo (ldquomoderaterdquo is notdefined by BfArM) evening primrose(Oenothera biennis) and a yeast preparationThe dosage of kava was well above the Ger-man Commission E recommended dose ofkavalactones (Blumenthal 1998) It was alsorecorded that 500ndash1000 mg of paracetamol wastaken by this patient shortly before transplan-tation The combination of paracetamol and al-cohol plus the very high dose of kava extractedin acetone taken by this man casts seriousdoubts on the assessment of probable in thiscase
Case 28 (BAH) This case concerned a
KAVA WORK-IN-PROGRESS 243
woman age unknown with hepatitis This caseis hard to assess because neither the patientrsquosage nor diagnosis was given and the womanwas taking eleven medications including estra-diol valerate acetylcysteine losartan (which israrely be associated with hepatitis) and mepra-zole (which can be associated with liver diseasealthough this is rare) Omeprazole is metabo-lized by the polymorphic CYP2C19 which is absent in 3 of Caucasians (Flockhart et al2000) The woman was also taking echinacea(Echinacea purpurea) and five products that ap-peared to be for upper respiratory problems Itshould be noted that this patient was taking syn-thetic kavain not kava A comment from BfArMconcerning this case noted ldquorecurrence of the he-patic side-effectsrdquo which has evidently been in-terpreted by some authorities as being equiva-lent to a ldquopositive rechallengerdquo Whether or notthis was actually so was not clear from the datasupplied It appears (Schmidt and Nahrstedt2002) that Case 28 has been published as twocases with slightly different details This is con-fusing and considering that the woman was tak-ing 11 other medications together with a syn-thetic kava (which we submit is not equivalentto natural kava) and that no diagnosis of hercondition was supplied this calls the assessmentof probable in this case into question
(2) Cases associated with taking synthetic kavain
In this category there were 4 cases 1 2 19and 28
In each of these cases the patients concernedwere taking a product made from synthetickavain Although the outcome was hepatitis inall four cases kavain cannot be equated withthe naturally occurring form of kava whichcontains many other constituents that may playan important role in ensuring the safety of thisherb Therefore we submit that no inferenceshould be drawn from these cases Traditionalusage should not be taken as evidence for safeusage of synthetic products
(3) Patients who were taking oral contraceptivepills or hormone replacement therapy (HRT)together with drugs that can also be associatedwith liver damage
The cases in this category were 4 10 12 2021 and 28
Cholestatic jaundice associated with use ofestrogen-containing medications is extremelyrare (Lindberg 1992) but does occur In these6 cases the women were also taking drugs thatcan also be associated with jaundice
Case 4 This case involved a 39-year-oldwoman with jaundice She was on diazepam10 mg PRN for 6 months Some authoritiescalled this case possible Our assessment is thatthe case is unassessable
Case 10 This case involved a 39-year-oldwoman with necrotizing hepatitis For a de-tailed assessment see above
Case 12 This case involved a 37-year-oldwoman with hepatitis She was on 150 mg ofdiclofenac via intramuscular injection Hepato-toxic reactions associated with nonsteroidalanti-inflammatory drug use are extremely rareand concomitant exposure to other hepatotoxicdrugs is considered to be an important factor(Bareille et al 2001) This case of hepatitis isdifficult to interpret because it occurred inBrazil and because ldquoreexposure was said to benegative for all three drugsrdquo We regard thiscase as unassessable
Case 20 This case involved 50-year-oldwoman with necrosis who had a liver trans-plant She had a 20-year history of combinedoral contraceptive use but had changed monthsearlier to estradiol valerate (which was appar-ently taken alone) as HRT She had also startedglimepiride 8 months earlier This is used fortreating type II diabetes and is rarely associatedwith cholestatic jaundice and liver failure Weregard this case as unlikely
Case 21 This case involved a 22-year-oldwoman with necrosis who had a liver trans-plant This woman had changed from Valette(Jenapharm GmbH Jena Germany) (2 mg ofdienogest and 003 mg of ethinlestradiol) toPramino (180215250 mcg of norgestimateand mcg 25 of ethinylestradiol) She also tookrizatriptan if required for migraine reliefRizatriptan should be used with caution in he-patic impairment and avoided if a patient hassevere liver disease Some authorities considerthis case as being possible but our assessment
DENHAM ET AL244
is in view of the other medications taken isthat this case is unassessable
Case 28 This case involved a woman age un-known with hepatitis This case is discussed atlength above As noted above this patient wastaking synthetic kavain not kava
(4) Patients who were taking drugs that can beassociated with liver damage
There were ten cases in this category 1 6 914 15 17 19 23 2627 and 29
Case 1 This case involved a woman age 69with cholestatic hepatitis She was taking pen-toxifylline (which can be associated with intra-hepatic cholestasis) and a diuretic including thepotassium-sparing triamterene (which can beassociated with jaundice) As noted above thispatient was taking synthetic kavain not kavaWe consider this case unassessable
Case 6 This case involved a woman age 50with hepatitis She was taking frusemide(which can be associated with cholestatic jaun-dice) triamterene atenolol and a large dose ofterfenadine (300 mg) The recommended doseof terfenadine in the British National Formu-lary (March 2001) is 60ndash120 mg The Formularyrecommends avoiding this drug in patientswho have hepatic impairment and also says toldquoavoid concomitant administration of drugs li-able to produce electrolyte imbalance such asdiureticsrdquo (British National Formulary 2001)Despite this warning this woman was also tak-ing the diuretic frusemide The InterkantonalenKontrollstelle der Schweiz of Switzerland con-sidered this case of hepatitis to be caused byterfenadine And although some authoritiesregard this case as possible our assessment isthat this case is unlikely
Case 9 This case involved an 81-year-oldwoman who had liver failure and subsequentdeath She was taking hydrochlorothiazide(which can occasionally be associated with in-trahepatic cholestasis) However according toSchmidt and Nahrstedt (2002) there was evi-dence of chronic alcohol abuse and they re-ported that the autopsy showed chronic pan-creatitis that was characteristic of alcoholabuse The autopsy report (Schmidt and
Nahrstedt 2002) apparently said that thesymptoms must have occurred over a periodof at least 18 months The report conceded thatldquohepatic impairment by alcohol [was] not ex-cludedrdquo In these circumstances it seems en-tirely reasonable to claim that this case is un-related to kava use We regard this case asunlikely
Case 14 This case involved a 33-year-oldwoman with hepatitis Cisapride may havebeen taken (which can cause reversible changesthat show in liver-function tests) Cirrhosis ina woman of 33 is an unexplained finding andthe detail in this case is inadequate to elucidateit We consider this case to be unassessable
Case 15 This case involved a 46-year-oldwoman with jaundice She had been taking hy-drochlorothiazide (which can be associatedwith intrahepatic cholestasis) for 55 monthsplus 80 mg of valsartan and 80 mg ofpropanolol per day Some authorities regardthis case as possible but we consider it to beunassessable
Case 17 This case involved a 59-year-oldwoman with jaundice She had taken 100ndash200mg of celecoxib a cyclo-oxygenase-2 inhibitorper day According to the criteria for causalityassessment of adverse reactions some author-ities consider this case to be possible but our as-sessment is that it is unassessable
Case 19 This case involved a 21-year-oldwoman with hepatitis She was taking panto-prazole (which as with omeprazole can be as-sociated with liver disease) She was also takingparacetamol and metoclopramide and had over-dosed on kavain More detail is needed on othermedical conditions suffered by this patient in or-der to interpret this case It is suggested bySchmidt that this woman was using up to 10tablets per day of the product (the recom-mended dose is up to 6 tablets per day) and thatthere was apparently a discussion in her med-ical record file that she may also have used Ec-stasy (substance that has been associated with
KAVA WORK-IN-PROGRESS 245
Personal communication from M McGuffin to M McIn-tyre available as an online document at ehpaglobalnetcouk
fulminant hepatic failure) This case appears tobe unassessable
Case 23 This case involved a 35-year-oldwoman with jaundice According to the BfArM(see Appendix 2) this patient also took parac-etamol but no dosage or details were providedThis case and case 25 in the BfArM listing ap-pear to be the same case Both cases have beenlabeled as possible by some authorities butgiven the lack of information about the dosageof paracetamol and the apparent confusion re-garding cases 23 and 25 we submit that theonly logical assessment is unassessable
Case 2627 This case involved a woman whowas either 38 or 39 yearsrsquo old with hepatitis Itappears that the two cases have been duplicated(Schmidt and Nahrstedt 2002) The confusionwith this case is another example of inaccuratedata provided by the BfArM Information re-garding these cases (or case) depending onwhether the two reports concern the samewoman is unclear Penicillin can be associatedwith hypersensitivity and cholestatic jaundicebut the information given is inadequate to makeany meaningful assessment For this reason weclass this case as unassessable
Case 29 This case involved a 60-year-oldwoman who had a liver transplant This womanwas taking piretamide (which is a loop diuretic)Frusemide another loop diuretic can be associ-ated with cholestatic jaundice According to theBfArM chart (see Appendix 2) she was also tak-ing a sympathomimetic drug etilefrin Thedosage of kava varied but was up to 480ndash1200mg per day (Schmidt and Nahrstedt 2002)which is up to ten times the German Commis-sion E maximum recommended dose (Blumen-thal 1998) Although some authorities have re-garded this case as possible in view of themarked overdosing of kava and the concomitantmedication this case can hardly be said to be areflection on the proper therapeutic use of kava
(5) Cases in which drugs not associated withliver damage herbal medicines or dietarysupplements or kavain alone were taken
This category had eight cases 2 78 11 1322 24 and 25
For these cases detail was limited and theBfArM did not implicate any other drugs ormedications (although this may not be thecase)
All patients in this group apart from the pa-tient in Case 78 for whom no information wasgiven were reported to have made full recov-eries In some of these cases it is not clearwhether the patients were ill or whether thesecases merely recorded raised liver-function en-zymes
Case 2 This case involved a 35-year-old manwith cholestatic hepatitis Concomitant med-ication was ldquounknownrdquo Apart from Cases 18and 30 this is the only case for which it is pos-sible that no other concomitant medication wastaken but there is a marked lack of informationfor this case As noted above this patient wastaking synthetic kavain not kava We regardthis case as unassessable
Case 5 This case involved a woman who waseither 68 or 69 yearsrsquo old with cholestatic he-patitis She was also taking a St Johnrsquos wort(Hypericum perforatum) product which hasbeen associated with CYP3A4 A biopsyshowed ldquoimmunologic hypersensitivityrdquo Thiscase may be regarded as possible but in viewof the immunologic hypersensitivity it maywell have been an idiosyncratic event that wasnot necessarily associated with kava usage
Case 78 This case involved a woman or twowomen ages 72 andor 75 with cholestatic he-patitis These two cases appear to be actuallyone case The woman was taking twoherbalvitamin products one of which in-cluded 06 mg of kavalactones Given the con-fusion involved these ldquocasesrdquo must be re-garded as unassessable
Case 11 This case involved a 59-year-oldwoman who was taking hyoscine butylbro-mide as a suppository Schmidt and Nahrstedt(2002) commented that according to additionalinformation obtained from the BfArM it is un-certain as to whether this patient was taking akava product at all We regard this case asunassessable
DENHAM ET AL246
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
for urinary problems (Ellingwood 1919) Theindications given in the British Herbal Pharma-copoeia (Anonymous 1983) are ldquoCystitis Ure-thritis Rheumatism and Infection of the gen-ito-urinary tractrdquo More recent texts emphasizethe herbrsquos usage as a nervine For example in-dications given by Mills and Bone (2000) areldquoanxiety of nervous origin nervous tensionrestlessness or mild depression of non-psy-chotic origin menopausal symptoms and in-flammation and infections of the genitourinarytracts of both men and women muscular andnervous pain and insomniardquo Kava use as anervine (which is its traditional therapeuticuse) has increased markedly in recent yearspartly because of the evidence for clinical effec-tiveness found in clinical trials (Pittler and Ernst2000) However it is interesting to note thatsuch usage is not completely new Felter (1905)notes kavarsquos application inter alia for treatingneuralgia dizziness and despondency Theherb has a particular value for treating agita-tion and anxiety (Spinella 2001) when othernervines have proved to be ineffective
Clinical trials have been reviewed recentlyby Pittler and Ernst (2000) who stated that for treating anxiety kavarsquos superiority overplacebo was suggested by all seven trials un-der review and that for the three trials in-cluded in the meta-analysis there was a sig-nificant reduction in score on the HamiltonAnxiety Scale The clinical trials were all car-ried out in Germany where kava is prescribedby physicians and sold over the counter inpharmacies for treating anxiety and insomniaA recent review (Loew 2002) listed nine dou-ble-blinded randomized controlled trials in-volving 808 patients and stated that kava wassignificantly superior to placebo for treatingsymptoms associated with anxiety These trialsused a range of products standardized on15ndash70 kavalactones providing a dailydosage of 60ndash210 mg per day of kavalactonesThe use of kava is being increasingly advocatedas an alternative to benzodiazepines for treat-ing anxiety and has been tested in at least onetrial (Loew 2002) The trial was 28 days longand involved 61 people And for example DeLeo et al (2001) showed a significant relativedecrease in anxiety in a double-blinded ran-domized trial on 40 menopausal women when
kava was combined with hormone replacementtherapy This trial lasted for 6 months and thedosage of kava extract was 100 mg per day (con-taining 55 mg of kavain) It has been claimed thatthe German Federal Institute for Drugs and Med-ical Products (German initials are BfArM) citeddoubts about kavarsquos efficacy for treating anxietyas one reason for starting an investigation on theherb (Anonymous 2001) Surprise was ex-pressed in Germany for this reason because itwas claimed (Anonymous 2001) that a recentrandomized controlled trial awaiting publicationhad demonstrated kavarsquos efficacy for this use atdoses that conform to the Commission E mono-graph on the herb (Blumenthal 2000)
The modern use of kava as a nervine is in ac-cordance with its traditional usage in the SouthPacific Kava drinkers report a sense of relax-ation and tranquillity and manifest a sociableattitude (Chanwai 2000) The herb is used as asocial and ceremonial drink among men inPolynesia In modern times as the influence ofthe Christian missionaries decreases kavarsquosuse has become more widespread and fre-quent For instance Kava is an important partof social life in Fiji Fijian spiritual leaders arecalled dauvaguna the literal translation ofwhich means ldquoexpert at drinking kavardquo(Greenwood-Robinson 1999) Kava is not ad-dictive and does not seem to produce the vio-lent antisocial effects that alcohol produces(Lebot et al 1997) However there are seriousconcerns in Australia (Clough et al 2000)about the herbrsquos abuse as a recreational drugwhen it is used to excess It has been associatedwith inactivity confusional states and generalill-health possibly as a result of associated mal-nutrition caused by irregular eating habits(Chanwai 2000) In Aboriginal communitiesmalnutrition is not uncommon and this associ-ation is considered to be unproven
WHAT IS KAVA
Root bark and root of kava are used eitherfresh or dried for its preparation
Based on an archaeological study of charac-teristic drinking bowls it has been proposedthat the herb was first domesticated in Polyne-sia more than 2000 years ago (Green 1974 [cited
DENHAM ET AL238
in Lebot et al 1997]) A comprehensive surveyby Lebot and Levesque in 1989 (cited in Lebotet al 1997) suggests that kava was originallydomesticated in the Vanuatu islands
Kava is now obtained from a wide range ofcultivars in the South Pacific The plant is al-ways propagated vegetatively from stem cut-tings as it does not reproduce via fertilizationmethods There are many cultivars and newstrains continue to be developed by Polynesianfarmers because each strain is considered tohave different psychoactive effects
In recent years there has been increasingpressure on the market because of the increasedworldwide demand for kava In 1998 it wasamong the top-selling herbs in the UnitedStates with a turnover of $8 million repre-senting a growth rate of 473 (Pittler and Ernst2000) It is possible that the current hepatotox-ity problems are to some extent a consequenceof poor quality control caused by a rapid andextraordinary increase in the size of the market(Murray 2000)
There are also concerns that intensive culti-vation and harvesting may affect the quality ofthe product (Aarlbersberg 1999) However be-ing that a range of products is implicated thisis unlikely to provide a satisfactory explanationfor all the reported adverse reactions It ishoped that the BfArM will release relevant dataabout the source and quality assurance of thekava supply in due course
KAVA PHARMACOLOGY
Kava is a well-researched herb The crys-talline resin was first isolated in 1857 by aFrench naval pharmacist and a detailed mono-graph was published in 1886 (Lewin 1886[cited by Lebot et al 1997]) The kavalactonesare considered to be the active constituents andhave been shown in animal studies to have asedative action (Hansel 1996) although themechanism is unclear (Spinella 2001) Thekavalactones are found in the resinous portion(5ndash9) of the plant material and are poorlysoluble in water
Kavalactones are 4-methoxy-2-pyrones withphenyl or styryl substituents at the 6th position(Lebot et al 1997) Total kavalactone content
varies from 3 to 20 dry weight Eighteen lac-tones have so far been isolated (He et al 1997)with the following six compounds (includingfour chiral enantiomers and two achiral enan-tiomers) being considered most important(Haberlain 1997 see Fig 1)
Chiral enantiomers(1) (1)-kavain(2) (1)-dihydrokavain(3) (1)-methysticin(4) (1)-dihydromethysticin
Achiral enantiomers(5) yangonin(6) demethoxyangonin
TRADITIONAL PREPARATION TECHNIQUES
Kava is traditionally prepared in the SouthPacific by grinding and mixing the root or rootbark with cold water This makes an emulsionthat is a suspension of the resinous constituentsin water (Lebot et al 1997) The herb is alsoprepared as an emulsion (also traditionallyprepared without heating) in coconut milk(Johnson 1999) The efficiency of extraction ofthe active constituents which is measured bykavalactone extraction into water varies con-siderably (Murray 2000) but is higher fromfresh material than from the dried plant Kavaconsumed in Vanuatu is reputed to be thestrongest anywhere in the South Pacific The is-lands of Tanna and Pentecost are especiallynoted for their potent brews It is thought thatpart of this increase in potency is the result ofpreparing the drink from the raw fresh rootswhereas in Fiji and elsewhere it is made fromdried rootstock (Greenwood-Robinson 1999)
MODERN PREPARATION TECHNIQUES
The bioavailability of kava constituentsvaries substantially depending on the methodof extraction (Hansel et al 1994 [cited in Schulzet al 1997] Loew 2002) Kava is predomi-nantly available in Germany as a so-called con-centrated standardized extract that is designedto maximize extraction of the kavalactones
KAVA WORK-IN-PROGRESS 239
Schulz noted that to create these concentratedstandardized extracts kava is dissolved in ahigh percentage of an ethanolndashwater mixtureto obtain extracts containing approximately30 kavalactones or alternatively using anacetonendashwater mixture to obtain extracts con-taining approximately 70 kavalactones Whit-ton Whitehouse and Evans (Appendix 1)make the same point about enhanced kavalac-tone extraction using a high ethanol or acetonemedium but detail somewhat different extrac-tion values Both types of products have a herb-to-extract ratio of approximately 12ndash201(Schulz 1997) The dosage recommended by theGerman Commission E is expressed as theequivalent of 60ndash120 mg of kavalactones per day(Blumenthal 1998)
The preparation methods used for stan-dardized products are highly technical and extraction rates vary (Kubatova et al 2001)depending on the solvents used and the tem-perature at which the products are preparedAs Whitton et al propose (Appendix 1) bothefficacy and safety may depend on thekavalactones remaining in their natural formsand on the extraction of the other natural con-stituents of the plant
Varying extraction techniques and preparationmethods may result in an unnatural variation inthe relative concentration of each lactone or inproduction artifacts that may be pathologic to theliver It should be noted that some commercialkava products may also contain syntheticracemic kavain that may have other characteris-tics than the naturally occurring product has Itis clear that these technical matters related to ex-traction techniques require further elucidation
Proponents of concentrated standardizedproducts assert that they provide an effectivedose within a consistent range The traditionalwater-based kava preparations of the Polyne-sian peoples and low-alcohol kava tincturesused by herbal practitioners have been consid-ered to be unreliable because the concentrationof active constituents is relatively low andvaries from kava batch to batch Howeverthere are four relevant counterarguments
(1) The whole range of the constituents mayproduce a more effective and safe medicine(Williamson 2001)
(2) Some constituents not necessarily consid-ered active may enhance the safety of themedicine (Appendix 1)
DENHAM ET AL240
OCH3
H3COyangonin
(+)-methysticin
O O
OCH3
demethoxyangonin
O O
OCH3
OO
OH
O
(+)-dihydromethysticin
OCH3
OO
OH
O
(+)-kavain
OCH3
OH
O
(+)-dihydrokavain
OCH3
OH
O
FIG 1 Kavapyrones of kava (Piper methysticum) Per Haberlein et al 1997
(3) Definitive isolation of the active constituentis elusive in other medicinal plants such asHypericum perforatum (McIntyre 2000Barnes et al 2001)
(4) Herbal practitioners rely on the synergy be-tween a whole range of constituents in theherb or herb within a herbal prescriptionwhich is individually prescribed for a pa-tient This positive interaction may alsohave the benefit of keeping levels of anyone constituent below the safety threshold
LOW-ALCOHOL TINCTURES
The Traditional Medicines Evaluation Com-mittee (TMEC) strongly advocates the use ofextraction techniques that closely approximatethose traditionally used in Polynesia Thiswould require the use of low-alcohol tincturesmade by the traditional cold macerationprocesses common to UK tincture makingThe reasons for this opinion are set out belowthey have also been explored by Whitton et al(Appendix 1)
Tinctures used by herbal practitioners areprepared by macerating dried kava in a mix-ture of water and ethanol It has been shownthat such extracts using 25 ethanol75 wa-ter contain up to 30 times fewer kavalactonesthan the concentrated standardized prepara-tions (Appendix 1) The traditional preparationmethod using a mixture of 25 ethanol75water extracts a wider range of the naturalkava constituents (Appendix 1)
DOSAGE AND OVERDOSAGE
Assuming a 15 25 tincture and an upperlimit of 20 kavalactones in the dried herb(concentrations stated as 3ndash20 see sectionon Pharmacology below) then 500 mL of theherb would contain (100 3 02 3 015) 5 3 g(3000 mg) of kavalactones In addition assum-ing a daily dosage of 5ndash10 mL of the 15 25tincture the daily dose of kavalactonesamounts to a maximum of 30ndash60 mg If the con-centration of kavalactones were lower for ex-ample at approximately 10 as appears to bethe case with regard to Australian kava dis-
cussed by Clough et al (2000) then this dosagefalls to 15ndash30 mg per day It is noteworthy thatthe maximum daily dosage here is equivalentto the minimum daily dosages of the 60ndash210mg kavalactones given in clinical trials of kavaconducted in Germany
Although standardized extracts provide ahigher dosage of kavalactones than low-alco-hol tinctures overdosage in itself is unlikelyto be the cause of hepatotoxicity Strong evi-dence for this is the fact that kava is takendaily at high doses as a normal part of dailylife in large areas of the South Pacific Indeedsome of the accounts of high kava intake areremarkable For example Chanwai (2000) de-scribed the case of a man who was admittedto a hospital after an overdose but ldquoslept offrdquohis symptoms and admitted to consuming upto 40 bowls of a kava preparation per day forthe last 14 years In Australia missionaries in-troduced kava to the aborigines in the 1980sas a substitute for alcohol and it is claimed thatthis has led to abuse of kava Clough et al(2000) discussed this concern and reviewedtwelve studies on the amount of kava usedThe researchers found that social setting ap-pears to determine the amount used with lonedrinkers consuming much more than peoplewho enjoy kava in a family group The re-searchers described normal use of kava in theNorthern Territory as being 37 g of kava pow-der (containing approximately 3800 mg ofkavalactones) per hour with heavy consumersusing approximately 610 g per week preparedas a drink The incidence of serious illness re-sulting from hepatotoxicity associated withregular kava usage would surely have beenobserved by the medical services in Polynesiaand Australia if overdosage of kavalactoneswere the main cause of hepatotoxicity
UNTOWARD EFFECTS
There is a justified concern in Europe thatidiosyncratic hepatotoxicity associated with us-ing some herbal medicines may not be identi-fied because the population that takes herbalmedicines is not large enough to produce suf-ficient cases for the association to be noted Butthe fact that kava remains in traditional usageto such a wide extent is a powerful argument
KAVA WORK-IN-PROGRESS 241
that idiosyncratic hepatotoxicity would havebeen noted
Two postmarketing observation studies inGermany each on more than 3000 people werecited by Pittler and Ernst (2000) in addition tothe abovementioned clinical trials In these ob-servational studies the rate of adverse eventswas 23 (with a daily dose of 120ndash240 mg ofkavalactones) and 15 (with a daily dose of105 mg of kavalactones) The most frequent ad-verse reports were gastrointestinal complaintsallergic skin reactions headaches and photo-sensitivity
There is evidence in the South Pacific of a char-acteristic kava-induced skin disease a scaly rashthat is suggestive of icthyosismdasha condition calledldquokava dermopathyrdquo (Ruze 1990) Although theskin becomes yellow the description does notsuggest an underlying hepatic condition in thatthe patient remains well the rash is not itchyand the condition is ameliorated without treat-ment if heavy use of kava is reduced
The German and Swiss reports cited by theBfArM are of concern because there have beenprevious reports of hepatotoxicity associatedwith the use of some medicinal plants (Larrey1997) The kava case reports from the BfArM(see Appendix 2) include all three of the mainforms of acute damage that can result from ad-verse drug reactions (1) necrosis (2) drug-in-duced hepatitis and (3) cholestatic hepatitis(Hodgson and Levi 1997) This suggests thatthere is a range of causes rather than just onecause in these cases The BfArM case reportshave been circulated worldwide and are cur-rently being evaluated by government agenciesin Europe Australia Canada the UnitedStates and elsewhere We have received anumber of informal case assessments fromthese sources that cannot be specifically citedbecause of their confidential status To achievetransparency and encourage a full debate aboutkava however the BfArM cases are evaluatedin the section entitled Discussion of Cases Re-ported by the BfArM
CRITERIA FOR ASSESSING THE CASE REPORTS
A recent review of the information availableon the case reports (Schmidt and Nahrstedt
2002) is supported by details of the case re-ports on the Web site of the University ofMuenster (wwwuni-muensterdechemiepbkavaanalysehtml)
The criteria for causality assessment of ad-verse reactions used are as follows (Edwardsand Aronson 2000)Probable is defined as
A clinical event including a laboratory testabnormality that occurs in a plausible timerelation to drug administration and that can-not be explained by coincidental or concur-rent disease or other drugs or chemicals
The response to withdrawal of the drug(dechallange) should be clinically plausible
The event must be definitive pharmacolog-ically or phenomenologically using a satis-factory rechallenge procedure if necessary
Possible is defined as
A clinical event including a laboratory testabnormality with a reasonable time relationto administration of the drug but that couldbe explained by concurrent disease or otherdrugs or chemicals
Information on drug withdrawal may belacking or unclear
Unlikely is defined as
A clinical event including a laboratory testabnormality with a temporal relation to theadministration of the drug which makes acausal relation improbable and in whichother drugs chemicals or underlying dis-ease provide plausible explanations
Unassessable is defined as
A report suggesting an adverse reaction thatcannot be judged because information is in-sufficient or contradictory and cannot besupplemented or verified
DISCUSSION OF CASES REPORTED BY THE BfArM
The cases discussed below are analyzed andcategorized by common factors of note withour own assessments
DENHAM ET AL242
(1) Cases of most concern
This group includes five cases 10 13 16 18and 28 According to the assessments made by various government agencies these casescause the most concern and are often cited asbeing probable For this reason these cases aredealt with first As discussed below mostmdashifnot allmdashof these cases have associated factorsthat put this probable categorization into ques-tion
Case 10 This case described necrotizing hep-atitis in a 39-year old female patient with pos-itive reexposure (Strahl et al 1998) During thefirst period that the kava product was takenan oral contraceptive and paroxetine were con-comitant medications It appears that paroxe-tine was not the only antidepressant taken bythis patient who also occasionally took StJohnrsquos wort (Hypericum perforatum) The Exec-utive Summary issued by the Bundesverbandder Arzneimittel Hersteller eV (BAH) andBundesverband der Pharmazeutischen Indus-trie eV (BP) (see Appendix 3) stated ldquoA causalrelationship with kava cannot be excluded butthe patientrsquos history and a potential preexistingliver damage must be taken into account In ad-dition the kava preparation used was not iden-tified by the physicianrdquo
Moreover in this case taking paroxetine incombination with an oral contraceptive maywell have led to overburdening the liver a sit-uation that could have been exacerbated by tak-ing a kava preparation Schmidt and Nahrstedt(2002) suggested that this case may be associ-ated with an immunologic reaction After re-viewing all of the cases in detail Schmidt andNahrstedt (2002) concluded that this is the onlycase for which there was sufficient informationto make an association with kava appear prob-able and for which the dose of kava also con-formed to that recommended by the Com-mission E monograph (Blumenthal 2000)However as discussed below Russmann et al(2001) tested this patient for CYP2D6 and as inCase 16 found this patient to be CYP2D6 defi-cient which appears to have made her partic-ularly vulnerable to the cocktail of drugs shewas taking Given the complicating features ofthis case we submit that this case should beclassed as possible rather than probable
Case 13 This was a case of a 62-year-oldwoman with jaundice The BfArM table (seeAppendix 2) noted regarding concomitantmedication that there was ldquonone denotedrdquo butit was claimed that concomitant medication didexist but was ldquounknownrdquo The insufficiency ofdata provided for this case was highlighted byBfArMrsquos warning note ldquoNo medical messagerdquoIn addition it should be noted that no detailsof the dosage of kava or period of its adminis-tration were apparently recorded for this caseThis is clearly insufficient information onwhich to base a probable assessment
Case 16 This case concerned a 33-year-oldwoman with jaundice The woman wasrecorded as having taken an overdose of alco-hol measured at 60 g (Russman et al 2001) andthen analgesics including paracetamol fol-lowing this alcohol binge Despite the massiveintake of alcohol a liver biopsy indicated thata drug rather than an alcohol induced toxicgenesis However this case like that of Case 10above was discussed by Russman et al (2001)who demonstrated afterward that this patientwas shown to be CYP2D6 deficient which (asdiscussed below) seems to be a risk factor forthe hepatotoxicity that was ascribed to kavaWe submit that given these circumstances thiscase should be considered possible rather thanprobable
Case 18 This case concerned a 50-year-oldman who had necrosis leading to a liver trans-plant This patient took a product manufac-tured by acetone extraction at a dose deliver-ing 210ndash280 mg of kavalactones per day for 15months ldquomoderate alcoholrdquo (ldquomoderaterdquo is notdefined by BfArM) evening primrose(Oenothera biennis) and a yeast preparationThe dosage of kava was well above the Ger-man Commission E recommended dose ofkavalactones (Blumenthal 1998) It was alsorecorded that 500ndash1000 mg of paracetamol wastaken by this patient shortly before transplan-tation The combination of paracetamol and al-cohol plus the very high dose of kava extractedin acetone taken by this man casts seriousdoubts on the assessment of probable in thiscase
Case 28 (BAH) This case concerned a
KAVA WORK-IN-PROGRESS 243
woman age unknown with hepatitis This caseis hard to assess because neither the patientrsquosage nor diagnosis was given and the womanwas taking eleven medications including estra-diol valerate acetylcysteine losartan (which israrely be associated with hepatitis) and mepra-zole (which can be associated with liver diseasealthough this is rare) Omeprazole is metabo-lized by the polymorphic CYP2C19 which is absent in 3 of Caucasians (Flockhart et al2000) The woman was also taking echinacea(Echinacea purpurea) and five products that ap-peared to be for upper respiratory problems Itshould be noted that this patient was taking syn-thetic kavain not kava A comment from BfArMconcerning this case noted ldquorecurrence of the he-patic side-effectsrdquo which has evidently been in-terpreted by some authorities as being equiva-lent to a ldquopositive rechallengerdquo Whether or notthis was actually so was not clear from the datasupplied It appears (Schmidt and Nahrstedt2002) that Case 28 has been published as twocases with slightly different details This is con-fusing and considering that the woman was tak-ing 11 other medications together with a syn-thetic kava (which we submit is not equivalentto natural kava) and that no diagnosis of hercondition was supplied this calls the assessmentof probable in this case into question
(2) Cases associated with taking synthetic kavain
In this category there were 4 cases 1 2 19and 28
In each of these cases the patients concernedwere taking a product made from synthetickavain Although the outcome was hepatitis inall four cases kavain cannot be equated withthe naturally occurring form of kava whichcontains many other constituents that may playan important role in ensuring the safety of thisherb Therefore we submit that no inferenceshould be drawn from these cases Traditionalusage should not be taken as evidence for safeusage of synthetic products
(3) Patients who were taking oral contraceptivepills or hormone replacement therapy (HRT)together with drugs that can also be associatedwith liver damage
The cases in this category were 4 10 12 2021 and 28
Cholestatic jaundice associated with use ofestrogen-containing medications is extremelyrare (Lindberg 1992) but does occur In these6 cases the women were also taking drugs thatcan also be associated with jaundice
Case 4 This case involved a 39-year-oldwoman with jaundice She was on diazepam10 mg PRN for 6 months Some authoritiescalled this case possible Our assessment is thatthe case is unassessable
Case 10 This case involved a 39-year-oldwoman with necrotizing hepatitis For a de-tailed assessment see above
Case 12 This case involved a 37-year-oldwoman with hepatitis She was on 150 mg ofdiclofenac via intramuscular injection Hepato-toxic reactions associated with nonsteroidalanti-inflammatory drug use are extremely rareand concomitant exposure to other hepatotoxicdrugs is considered to be an important factor(Bareille et al 2001) This case of hepatitis isdifficult to interpret because it occurred inBrazil and because ldquoreexposure was said to benegative for all three drugsrdquo We regard thiscase as unassessable
Case 20 This case involved 50-year-oldwoman with necrosis who had a liver trans-plant She had a 20-year history of combinedoral contraceptive use but had changed monthsearlier to estradiol valerate (which was appar-ently taken alone) as HRT She had also startedglimepiride 8 months earlier This is used fortreating type II diabetes and is rarely associatedwith cholestatic jaundice and liver failure Weregard this case as unlikely
Case 21 This case involved a 22-year-oldwoman with necrosis who had a liver trans-plant This woman had changed from Valette(Jenapharm GmbH Jena Germany) (2 mg ofdienogest and 003 mg of ethinlestradiol) toPramino (180215250 mcg of norgestimateand mcg 25 of ethinylestradiol) She also tookrizatriptan if required for migraine reliefRizatriptan should be used with caution in he-patic impairment and avoided if a patient hassevere liver disease Some authorities considerthis case as being possible but our assessment
DENHAM ET AL244
is in view of the other medications taken isthat this case is unassessable
Case 28 This case involved a woman age un-known with hepatitis This case is discussed atlength above As noted above this patient wastaking synthetic kavain not kava
(4) Patients who were taking drugs that can beassociated with liver damage
There were ten cases in this category 1 6 914 15 17 19 23 2627 and 29
Case 1 This case involved a woman age 69with cholestatic hepatitis She was taking pen-toxifylline (which can be associated with intra-hepatic cholestasis) and a diuretic including thepotassium-sparing triamterene (which can beassociated with jaundice) As noted above thispatient was taking synthetic kavain not kavaWe consider this case unassessable
Case 6 This case involved a woman age 50with hepatitis She was taking frusemide(which can be associated with cholestatic jaun-dice) triamterene atenolol and a large dose ofterfenadine (300 mg) The recommended doseof terfenadine in the British National Formu-lary (March 2001) is 60ndash120 mg The Formularyrecommends avoiding this drug in patientswho have hepatic impairment and also says toldquoavoid concomitant administration of drugs li-able to produce electrolyte imbalance such asdiureticsrdquo (British National Formulary 2001)Despite this warning this woman was also tak-ing the diuretic frusemide The InterkantonalenKontrollstelle der Schweiz of Switzerland con-sidered this case of hepatitis to be caused byterfenadine And although some authoritiesregard this case as possible our assessment isthat this case is unlikely
Case 9 This case involved an 81-year-oldwoman who had liver failure and subsequentdeath She was taking hydrochlorothiazide(which can occasionally be associated with in-trahepatic cholestasis) However according toSchmidt and Nahrstedt (2002) there was evi-dence of chronic alcohol abuse and they re-ported that the autopsy showed chronic pan-creatitis that was characteristic of alcoholabuse The autopsy report (Schmidt and
Nahrstedt 2002) apparently said that thesymptoms must have occurred over a periodof at least 18 months The report conceded thatldquohepatic impairment by alcohol [was] not ex-cludedrdquo In these circumstances it seems en-tirely reasonable to claim that this case is un-related to kava use We regard this case asunlikely
Case 14 This case involved a 33-year-oldwoman with hepatitis Cisapride may havebeen taken (which can cause reversible changesthat show in liver-function tests) Cirrhosis ina woman of 33 is an unexplained finding andthe detail in this case is inadequate to elucidateit We consider this case to be unassessable
Case 15 This case involved a 46-year-oldwoman with jaundice She had been taking hy-drochlorothiazide (which can be associatedwith intrahepatic cholestasis) for 55 monthsplus 80 mg of valsartan and 80 mg ofpropanolol per day Some authorities regardthis case as possible but we consider it to beunassessable
Case 17 This case involved a 59-year-oldwoman with jaundice She had taken 100ndash200mg of celecoxib a cyclo-oxygenase-2 inhibitorper day According to the criteria for causalityassessment of adverse reactions some author-ities consider this case to be possible but our as-sessment is that it is unassessable
Case 19 This case involved a 21-year-oldwoman with hepatitis She was taking panto-prazole (which as with omeprazole can be as-sociated with liver disease) She was also takingparacetamol and metoclopramide and had over-dosed on kavain More detail is needed on othermedical conditions suffered by this patient in or-der to interpret this case It is suggested bySchmidt that this woman was using up to 10tablets per day of the product (the recom-mended dose is up to 6 tablets per day) and thatthere was apparently a discussion in her med-ical record file that she may also have used Ec-stasy (substance that has been associated with
KAVA WORK-IN-PROGRESS 245
Personal communication from M McGuffin to M McIn-tyre available as an online document at ehpaglobalnetcouk
fulminant hepatic failure) This case appears tobe unassessable
Case 23 This case involved a 35-year-oldwoman with jaundice According to the BfArM(see Appendix 2) this patient also took parac-etamol but no dosage or details were providedThis case and case 25 in the BfArM listing ap-pear to be the same case Both cases have beenlabeled as possible by some authorities butgiven the lack of information about the dosageof paracetamol and the apparent confusion re-garding cases 23 and 25 we submit that theonly logical assessment is unassessable
Case 2627 This case involved a woman whowas either 38 or 39 yearsrsquo old with hepatitis Itappears that the two cases have been duplicated(Schmidt and Nahrstedt 2002) The confusionwith this case is another example of inaccuratedata provided by the BfArM Information re-garding these cases (or case) depending onwhether the two reports concern the samewoman is unclear Penicillin can be associatedwith hypersensitivity and cholestatic jaundicebut the information given is inadequate to makeany meaningful assessment For this reason weclass this case as unassessable
Case 29 This case involved a 60-year-oldwoman who had a liver transplant This womanwas taking piretamide (which is a loop diuretic)Frusemide another loop diuretic can be associ-ated with cholestatic jaundice According to theBfArM chart (see Appendix 2) she was also tak-ing a sympathomimetic drug etilefrin Thedosage of kava varied but was up to 480ndash1200mg per day (Schmidt and Nahrstedt 2002)which is up to ten times the German Commis-sion E maximum recommended dose (Blumen-thal 1998) Although some authorities have re-garded this case as possible in view of themarked overdosing of kava and the concomitantmedication this case can hardly be said to be areflection on the proper therapeutic use of kava
(5) Cases in which drugs not associated withliver damage herbal medicines or dietarysupplements or kavain alone were taken
This category had eight cases 2 78 11 1322 24 and 25
For these cases detail was limited and theBfArM did not implicate any other drugs ormedications (although this may not be thecase)
All patients in this group apart from the pa-tient in Case 78 for whom no information wasgiven were reported to have made full recov-eries In some of these cases it is not clearwhether the patients were ill or whether thesecases merely recorded raised liver-function en-zymes
Case 2 This case involved a 35-year-old manwith cholestatic hepatitis Concomitant med-ication was ldquounknownrdquo Apart from Cases 18and 30 this is the only case for which it is pos-sible that no other concomitant medication wastaken but there is a marked lack of informationfor this case As noted above this patient wastaking synthetic kavain not kava We regardthis case as unassessable
Case 5 This case involved a woman who waseither 68 or 69 yearsrsquo old with cholestatic he-patitis She was also taking a St Johnrsquos wort(Hypericum perforatum) product which hasbeen associated with CYP3A4 A biopsyshowed ldquoimmunologic hypersensitivityrdquo Thiscase may be regarded as possible but in viewof the immunologic hypersensitivity it maywell have been an idiosyncratic event that wasnot necessarily associated with kava usage
Case 78 This case involved a woman or twowomen ages 72 andor 75 with cholestatic he-patitis These two cases appear to be actuallyone case The woman was taking twoherbalvitamin products one of which in-cluded 06 mg of kavalactones Given the con-fusion involved these ldquocasesrdquo must be re-garded as unassessable
Case 11 This case involved a 59-year-oldwoman who was taking hyoscine butylbro-mide as a suppository Schmidt and Nahrstedt(2002) commented that according to additionalinformation obtained from the BfArM it is un-certain as to whether this patient was taking akava product at all We regard this case asunassessable
DENHAM ET AL246
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
in Lebot et al 1997]) A comprehensive surveyby Lebot and Levesque in 1989 (cited in Lebotet al 1997) suggests that kava was originallydomesticated in the Vanuatu islands
Kava is now obtained from a wide range ofcultivars in the South Pacific The plant is al-ways propagated vegetatively from stem cut-tings as it does not reproduce via fertilizationmethods There are many cultivars and newstrains continue to be developed by Polynesianfarmers because each strain is considered tohave different psychoactive effects
In recent years there has been increasingpressure on the market because of the increasedworldwide demand for kava In 1998 it wasamong the top-selling herbs in the UnitedStates with a turnover of $8 million repre-senting a growth rate of 473 (Pittler and Ernst2000) It is possible that the current hepatotox-ity problems are to some extent a consequenceof poor quality control caused by a rapid andextraordinary increase in the size of the market(Murray 2000)
There are also concerns that intensive culti-vation and harvesting may affect the quality ofthe product (Aarlbersberg 1999) However be-ing that a range of products is implicated thisis unlikely to provide a satisfactory explanationfor all the reported adverse reactions It ishoped that the BfArM will release relevant dataabout the source and quality assurance of thekava supply in due course
KAVA PHARMACOLOGY
Kava is a well-researched herb The crys-talline resin was first isolated in 1857 by aFrench naval pharmacist and a detailed mono-graph was published in 1886 (Lewin 1886[cited by Lebot et al 1997]) The kavalactonesare considered to be the active constituents andhave been shown in animal studies to have asedative action (Hansel 1996) although themechanism is unclear (Spinella 2001) Thekavalactones are found in the resinous portion(5ndash9) of the plant material and are poorlysoluble in water
Kavalactones are 4-methoxy-2-pyrones withphenyl or styryl substituents at the 6th position(Lebot et al 1997) Total kavalactone content
varies from 3 to 20 dry weight Eighteen lac-tones have so far been isolated (He et al 1997)with the following six compounds (includingfour chiral enantiomers and two achiral enan-tiomers) being considered most important(Haberlain 1997 see Fig 1)
Chiral enantiomers(1) (1)-kavain(2) (1)-dihydrokavain(3) (1)-methysticin(4) (1)-dihydromethysticin
Achiral enantiomers(5) yangonin(6) demethoxyangonin
TRADITIONAL PREPARATION TECHNIQUES
Kava is traditionally prepared in the SouthPacific by grinding and mixing the root or rootbark with cold water This makes an emulsionthat is a suspension of the resinous constituentsin water (Lebot et al 1997) The herb is alsoprepared as an emulsion (also traditionallyprepared without heating) in coconut milk(Johnson 1999) The efficiency of extraction ofthe active constituents which is measured bykavalactone extraction into water varies con-siderably (Murray 2000) but is higher fromfresh material than from the dried plant Kavaconsumed in Vanuatu is reputed to be thestrongest anywhere in the South Pacific The is-lands of Tanna and Pentecost are especiallynoted for their potent brews It is thought thatpart of this increase in potency is the result ofpreparing the drink from the raw fresh rootswhereas in Fiji and elsewhere it is made fromdried rootstock (Greenwood-Robinson 1999)
MODERN PREPARATION TECHNIQUES
The bioavailability of kava constituentsvaries substantially depending on the methodof extraction (Hansel et al 1994 [cited in Schulzet al 1997] Loew 2002) Kava is predomi-nantly available in Germany as a so-called con-centrated standardized extract that is designedto maximize extraction of the kavalactones
KAVA WORK-IN-PROGRESS 239
Schulz noted that to create these concentratedstandardized extracts kava is dissolved in ahigh percentage of an ethanolndashwater mixtureto obtain extracts containing approximately30 kavalactones or alternatively using anacetonendashwater mixture to obtain extracts con-taining approximately 70 kavalactones Whit-ton Whitehouse and Evans (Appendix 1)make the same point about enhanced kavalac-tone extraction using a high ethanol or acetonemedium but detail somewhat different extrac-tion values Both types of products have a herb-to-extract ratio of approximately 12ndash201(Schulz 1997) The dosage recommended by theGerman Commission E is expressed as theequivalent of 60ndash120 mg of kavalactones per day(Blumenthal 1998)
The preparation methods used for stan-dardized products are highly technical and extraction rates vary (Kubatova et al 2001)depending on the solvents used and the tem-perature at which the products are preparedAs Whitton et al propose (Appendix 1) bothefficacy and safety may depend on thekavalactones remaining in their natural formsand on the extraction of the other natural con-stituents of the plant
Varying extraction techniques and preparationmethods may result in an unnatural variation inthe relative concentration of each lactone or inproduction artifacts that may be pathologic to theliver It should be noted that some commercialkava products may also contain syntheticracemic kavain that may have other characteris-tics than the naturally occurring product has Itis clear that these technical matters related to ex-traction techniques require further elucidation
Proponents of concentrated standardizedproducts assert that they provide an effectivedose within a consistent range The traditionalwater-based kava preparations of the Polyne-sian peoples and low-alcohol kava tincturesused by herbal practitioners have been consid-ered to be unreliable because the concentrationof active constituents is relatively low andvaries from kava batch to batch Howeverthere are four relevant counterarguments
(1) The whole range of the constituents mayproduce a more effective and safe medicine(Williamson 2001)
(2) Some constituents not necessarily consid-ered active may enhance the safety of themedicine (Appendix 1)
DENHAM ET AL240
OCH3
H3COyangonin
(+)-methysticin
O O
OCH3
demethoxyangonin
O O
OCH3
OO
OH
O
(+)-dihydromethysticin
OCH3
OO
OH
O
(+)-kavain
OCH3
OH
O
(+)-dihydrokavain
OCH3
OH
O
FIG 1 Kavapyrones of kava (Piper methysticum) Per Haberlein et al 1997
(3) Definitive isolation of the active constituentis elusive in other medicinal plants such asHypericum perforatum (McIntyre 2000Barnes et al 2001)
(4) Herbal practitioners rely on the synergy be-tween a whole range of constituents in theherb or herb within a herbal prescriptionwhich is individually prescribed for a pa-tient This positive interaction may alsohave the benefit of keeping levels of anyone constituent below the safety threshold
LOW-ALCOHOL TINCTURES
The Traditional Medicines Evaluation Com-mittee (TMEC) strongly advocates the use ofextraction techniques that closely approximatethose traditionally used in Polynesia Thiswould require the use of low-alcohol tincturesmade by the traditional cold macerationprocesses common to UK tincture makingThe reasons for this opinion are set out belowthey have also been explored by Whitton et al(Appendix 1)
Tinctures used by herbal practitioners areprepared by macerating dried kava in a mix-ture of water and ethanol It has been shownthat such extracts using 25 ethanol75 wa-ter contain up to 30 times fewer kavalactonesthan the concentrated standardized prepara-tions (Appendix 1) The traditional preparationmethod using a mixture of 25 ethanol75water extracts a wider range of the naturalkava constituents (Appendix 1)
DOSAGE AND OVERDOSAGE
Assuming a 15 25 tincture and an upperlimit of 20 kavalactones in the dried herb(concentrations stated as 3ndash20 see sectionon Pharmacology below) then 500 mL of theherb would contain (100 3 02 3 015) 5 3 g(3000 mg) of kavalactones In addition assum-ing a daily dosage of 5ndash10 mL of the 15 25tincture the daily dose of kavalactonesamounts to a maximum of 30ndash60 mg If the con-centration of kavalactones were lower for ex-ample at approximately 10 as appears to bethe case with regard to Australian kava dis-
cussed by Clough et al (2000) then this dosagefalls to 15ndash30 mg per day It is noteworthy thatthe maximum daily dosage here is equivalentto the minimum daily dosages of the 60ndash210mg kavalactones given in clinical trials of kavaconducted in Germany
Although standardized extracts provide ahigher dosage of kavalactones than low-alco-hol tinctures overdosage in itself is unlikelyto be the cause of hepatotoxicity Strong evi-dence for this is the fact that kava is takendaily at high doses as a normal part of dailylife in large areas of the South Pacific Indeedsome of the accounts of high kava intake areremarkable For example Chanwai (2000) de-scribed the case of a man who was admittedto a hospital after an overdose but ldquoslept offrdquohis symptoms and admitted to consuming upto 40 bowls of a kava preparation per day forthe last 14 years In Australia missionaries in-troduced kava to the aborigines in the 1980sas a substitute for alcohol and it is claimed thatthis has led to abuse of kava Clough et al(2000) discussed this concern and reviewedtwelve studies on the amount of kava usedThe researchers found that social setting ap-pears to determine the amount used with lonedrinkers consuming much more than peoplewho enjoy kava in a family group The re-searchers described normal use of kava in theNorthern Territory as being 37 g of kava pow-der (containing approximately 3800 mg ofkavalactones) per hour with heavy consumersusing approximately 610 g per week preparedas a drink The incidence of serious illness re-sulting from hepatotoxicity associated withregular kava usage would surely have beenobserved by the medical services in Polynesiaand Australia if overdosage of kavalactoneswere the main cause of hepatotoxicity
UNTOWARD EFFECTS
There is a justified concern in Europe thatidiosyncratic hepatotoxicity associated with us-ing some herbal medicines may not be identi-fied because the population that takes herbalmedicines is not large enough to produce suf-ficient cases for the association to be noted Butthe fact that kava remains in traditional usageto such a wide extent is a powerful argument
KAVA WORK-IN-PROGRESS 241
that idiosyncratic hepatotoxicity would havebeen noted
Two postmarketing observation studies inGermany each on more than 3000 people werecited by Pittler and Ernst (2000) in addition tothe abovementioned clinical trials In these ob-servational studies the rate of adverse eventswas 23 (with a daily dose of 120ndash240 mg ofkavalactones) and 15 (with a daily dose of105 mg of kavalactones) The most frequent ad-verse reports were gastrointestinal complaintsallergic skin reactions headaches and photo-sensitivity
There is evidence in the South Pacific of a char-acteristic kava-induced skin disease a scaly rashthat is suggestive of icthyosismdasha condition calledldquokava dermopathyrdquo (Ruze 1990) Although theskin becomes yellow the description does notsuggest an underlying hepatic condition in thatthe patient remains well the rash is not itchyand the condition is ameliorated without treat-ment if heavy use of kava is reduced
The German and Swiss reports cited by theBfArM are of concern because there have beenprevious reports of hepatotoxicity associatedwith the use of some medicinal plants (Larrey1997) The kava case reports from the BfArM(see Appendix 2) include all three of the mainforms of acute damage that can result from ad-verse drug reactions (1) necrosis (2) drug-in-duced hepatitis and (3) cholestatic hepatitis(Hodgson and Levi 1997) This suggests thatthere is a range of causes rather than just onecause in these cases The BfArM case reportshave been circulated worldwide and are cur-rently being evaluated by government agenciesin Europe Australia Canada the UnitedStates and elsewhere We have received anumber of informal case assessments fromthese sources that cannot be specifically citedbecause of their confidential status To achievetransparency and encourage a full debate aboutkava however the BfArM cases are evaluatedin the section entitled Discussion of Cases Re-ported by the BfArM
CRITERIA FOR ASSESSING THE CASE REPORTS
A recent review of the information availableon the case reports (Schmidt and Nahrstedt
2002) is supported by details of the case re-ports on the Web site of the University ofMuenster (wwwuni-muensterdechemiepbkavaanalysehtml)
The criteria for causality assessment of ad-verse reactions used are as follows (Edwardsand Aronson 2000)Probable is defined as
A clinical event including a laboratory testabnormality that occurs in a plausible timerelation to drug administration and that can-not be explained by coincidental or concur-rent disease or other drugs or chemicals
The response to withdrawal of the drug(dechallange) should be clinically plausible
The event must be definitive pharmacolog-ically or phenomenologically using a satis-factory rechallenge procedure if necessary
Possible is defined as
A clinical event including a laboratory testabnormality with a reasonable time relationto administration of the drug but that couldbe explained by concurrent disease or otherdrugs or chemicals
Information on drug withdrawal may belacking or unclear
Unlikely is defined as
A clinical event including a laboratory testabnormality with a temporal relation to theadministration of the drug which makes acausal relation improbable and in whichother drugs chemicals or underlying dis-ease provide plausible explanations
Unassessable is defined as
A report suggesting an adverse reaction thatcannot be judged because information is in-sufficient or contradictory and cannot besupplemented or verified
DISCUSSION OF CASES REPORTED BY THE BfArM
The cases discussed below are analyzed andcategorized by common factors of note withour own assessments
DENHAM ET AL242
(1) Cases of most concern
This group includes five cases 10 13 16 18and 28 According to the assessments made by various government agencies these casescause the most concern and are often cited asbeing probable For this reason these cases aredealt with first As discussed below mostmdashifnot allmdashof these cases have associated factorsthat put this probable categorization into ques-tion
Case 10 This case described necrotizing hep-atitis in a 39-year old female patient with pos-itive reexposure (Strahl et al 1998) During thefirst period that the kava product was takenan oral contraceptive and paroxetine were con-comitant medications It appears that paroxe-tine was not the only antidepressant taken bythis patient who also occasionally took StJohnrsquos wort (Hypericum perforatum) The Exec-utive Summary issued by the Bundesverbandder Arzneimittel Hersteller eV (BAH) andBundesverband der Pharmazeutischen Indus-trie eV (BP) (see Appendix 3) stated ldquoA causalrelationship with kava cannot be excluded butthe patientrsquos history and a potential preexistingliver damage must be taken into account In ad-dition the kava preparation used was not iden-tified by the physicianrdquo
Moreover in this case taking paroxetine incombination with an oral contraceptive maywell have led to overburdening the liver a sit-uation that could have been exacerbated by tak-ing a kava preparation Schmidt and Nahrstedt(2002) suggested that this case may be associ-ated with an immunologic reaction After re-viewing all of the cases in detail Schmidt andNahrstedt (2002) concluded that this is the onlycase for which there was sufficient informationto make an association with kava appear prob-able and for which the dose of kava also con-formed to that recommended by the Com-mission E monograph (Blumenthal 2000)However as discussed below Russmann et al(2001) tested this patient for CYP2D6 and as inCase 16 found this patient to be CYP2D6 defi-cient which appears to have made her partic-ularly vulnerable to the cocktail of drugs shewas taking Given the complicating features ofthis case we submit that this case should beclassed as possible rather than probable
Case 13 This was a case of a 62-year-oldwoman with jaundice The BfArM table (seeAppendix 2) noted regarding concomitantmedication that there was ldquonone denotedrdquo butit was claimed that concomitant medication didexist but was ldquounknownrdquo The insufficiency ofdata provided for this case was highlighted byBfArMrsquos warning note ldquoNo medical messagerdquoIn addition it should be noted that no detailsof the dosage of kava or period of its adminis-tration were apparently recorded for this caseThis is clearly insufficient information onwhich to base a probable assessment
Case 16 This case concerned a 33-year-oldwoman with jaundice The woman wasrecorded as having taken an overdose of alco-hol measured at 60 g (Russman et al 2001) andthen analgesics including paracetamol fol-lowing this alcohol binge Despite the massiveintake of alcohol a liver biopsy indicated thata drug rather than an alcohol induced toxicgenesis However this case like that of Case 10above was discussed by Russman et al (2001)who demonstrated afterward that this patientwas shown to be CYP2D6 deficient which (asdiscussed below) seems to be a risk factor forthe hepatotoxicity that was ascribed to kavaWe submit that given these circumstances thiscase should be considered possible rather thanprobable
Case 18 This case concerned a 50-year-oldman who had necrosis leading to a liver trans-plant This patient took a product manufac-tured by acetone extraction at a dose deliver-ing 210ndash280 mg of kavalactones per day for 15months ldquomoderate alcoholrdquo (ldquomoderaterdquo is notdefined by BfArM) evening primrose(Oenothera biennis) and a yeast preparationThe dosage of kava was well above the Ger-man Commission E recommended dose ofkavalactones (Blumenthal 1998) It was alsorecorded that 500ndash1000 mg of paracetamol wastaken by this patient shortly before transplan-tation The combination of paracetamol and al-cohol plus the very high dose of kava extractedin acetone taken by this man casts seriousdoubts on the assessment of probable in thiscase
Case 28 (BAH) This case concerned a
KAVA WORK-IN-PROGRESS 243
woman age unknown with hepatitis This caseis hard to assess because neither the patientrsquosage nor diagnosis was given and the womanwas taking eleven medications including estra-diol valerate acetylcysteine losartan (which israrely be associated with hepatitis) and mepra-zole (which can be associated with liver diseasealthough this is rare) Omeprazole is metabo-lized by the polymorphic CYP2C19 which is absent in 3 of Caucasians (Flockhart et al2000) The woman was also taking echinacea(Echinacea purpurea) and five products that ap-peared to be for upper respiratory problems Itshould be noted that this patient was taking syn-thetic kavain not kava A comment from BfArMconcerning this case noted ldquorecurrence of the he-patic side-effectsrdquo which has evidently been in-terpreted by some authorities as being equiva-lent to a ldquopositive rechallengerdquo Whether or notthis was actually so was not clear from the datasupplied It appears (Schmidt and Nahrstedt2002) that Case 28 has been published as twocases with slightly different details This is con-fusing and considering that the woman was tak-ing 11 other medications together with a syn-thetic kava (which we submit is not equivalentto natural kava) and that no diagnosis of hercondition was supplied this calls the assessmentof probable in this case into question
(2) Cases associated with taking synthetic kavain
In this category there were 4 cases 1 2 19and 28
In each of these cases the patients concernedwere taking a product made from synthetickavain Although the outcome was hepatitis inall four cases kavain cannot be equated withthe naturally occurring form of kava whichcontains many other constituents that may playan important role in ensuring the safety of thisherb Therefore we submit that no inferenceshould be drawn from these cases Traditionalusage should not be taken as evidence for safeusage of synthetic products
(3) Patients who were taking oral contraceptivepills or hormone replacement therapy (HRT)together with drugs that can also be associatedwith liver damage
The cases in this category were 4 10 12 2021 and 28
Cholestatic jaundice associated with use ofestrogen-containing medications is extremelyrare (Lindberg 1992) but does occur In these6 cases the women were also taking drugs thatcan also be associated with jaundice
Case 4 This case involved a 39-year-oldwoman with jaundice She was on diazepam10 mg PRN for 6 months Some authoritiescalled this case possible Our assessment is thatthe case is unassessable
Case 10 This case involved a 39-year-oldwoman with necrotizing hepatitis For a de-tailed assessment see above
Case 12 This case involved a 37-year-oldwoman with hepatitis She was on 150 mg ofdiclofenac via intramuscular injection Hepato-toxic reactions associated with nonsteroidalanti-inflammatory drug use are extremely rareand concomitant exposure to other hepatotoxicdrugs is considered to be an important factor(Bareille et al 2001) This case of hepatitis isdifficult to interpret because it occurred inBrazil and because ldquoreexposure was said to benegative for all three drugsrdquo We regard thiscase as unassessable
Case 20 This case involved 50-year-oldwoman with necrosis who had a liver trans-plant She had a 20-year history of combinedoral contraceptive use but had changed monthsearlier to estradiol valerate (which was appar-ently taken alone) as HRT She had also startedglimepiride 8 months earlier This is used fortreating type II diabetes and is rarely associatedwith cholestatic jaundice and liver failure Weregard this case as unlikely
Case 21 This case involved a 22-year-oldwoman with necrosis who had a liver trans-plant This woman had changed from Valette(Jenapharm GmbH Jena Germany) (2 mg ofdienogest and 003 mg of ethinlestradiol) toPramino (180215250 mcg of norgestimateand mcg 25 of ethinylestradiol) She also tookrizatriptan if required for migraine reliefRizatriptan should be used with caution in he-patic impairment and avoided if a patient hassevere liver disease Some authorities considerthis case as being possible but our assessment
DENHAM ET AL244
is in view of the other medications taken isthat this case is unassessable
Case 28 This case involved a woman age un-known with hepatitis This case is discussed atlength above As noted above this patient wastaking synthetic kavain not kava
(4) Patients who were taking drugs that can beassociated with liver damage
There were ten cases in this category 1 6 914 15 17 19 23 2627 and 29
Case 1 This case involved a woman age 69with cholestatic hepatitis She was taking pen-toxifylline (which can be associated with intra-hepatic cholestasis) and a diuretic including thepotassium-sparing triamterene (which can beassociated with jaundice) As noted above thispatient was taking synthetic kavain not kavaWe consider this case unassessable
Case 6 This case involved a woman age 50with hepatitis She was taking frusemide(which can be associated with cholestatic jaun-dice) triamterene atenolol and a large dose ofterfenadine (300 mg) The recommended doseof terfenadine in the British National Formu-lary (March 2001) is 60ndash120 mg The Formularyrecommends avoiding this drug in patientswho have hepatic impairment and also says toldquoavoid concomitant administration of drugs li-able to produce electrolyte imbalance such asdiureticsrdquo (British National Formulary 2001)Despite this warning this woman was also tak-ing the diuretic frusemide The InterkantonalenKontrollstelle der Schweiz of Switzerland con-sidered this case of hepatitis to be caused byterfenadine And although some authoritiesregard this case as possible our assessment isthat this case is unlikely
Case 9 This case involved an 81-year-oldwoman who had liver failure and subsequentdeath She was taking hydrochlorothiazide(which can occasionally be associated with in-trahepatic cholestasis) However according toSchmidt and Nahrstedt (2002) there was evi-dence of chronic alcohol abuse and they re-ported that the autopsy showed chronic pan-creatitis that was characteristic of alcoholabuse The autopsy report (Schmidt and
Nahrstedt 2002) apparently said that thesymptoms must have occurred over a periodof at least 18 months The report conceded thatldquohepatic impairment by alcohol [was] not ex-cludedrdquo In these circumstances it seems en-tirely reasonable to claim that this case is un-related to kava use We regard this case asunlikely
Case 14 This case involved a 33-year-oldwoman with hepatitis Cisapride may havebeen taken (which can cause reversible changesthat show in liver-function tests) Cirrhosis ina woman of 33 is an unexplained finding andthe detail in this case is inadequate to elucidateit We consider this case to be unassessable
Case 15 This case involved a 46-year-oldwoman with jaundice She had been taking hy-drochlorothiazide (which can be associatedwith intrahepatic cholestasis) for 55 monthsplus 80 mg of valsartan and 80 mg ofpropanolol per day Some authorities regardthis case as possible but we consider it to beunassessable
Case 17 This case involved a 59-year-oldwoman with jaundice She had taken 100ndash200mg of celecoxib a cyclo-oxygenase-2 inhibitorper day According to the criteria for causalityassessment of adverse reactions some author-ities consider this case to be possible but our as-sessment is that it is unassessable
Case 19 This case involved a 21-year-oldwoman with hepatitis She was taking panto-prazole (which as with omeprazole can be as-sociated with liver disease) She was also takingparacetamol and metoclopramide and had over-dosed on kavain More detail is needed on othermedical conditions suffered by this patient in or-der to interpret this case It is suggested bySchmidt that this woman was using up to 10tablets per day of the product (the recom-mended dose is up to 6 tablets per day) and thatthere was apparently a discussion in her med-ical record file that she may also have used Ec-stasy (substance that has been associated with
KAVA WORK-IN-PROGRESS 245
Personal communication from M McGuffin to M McIn-tyre available as an online document at ehpaglobalnetcouk
fulminant hepatic failure) This case appears tobe unassessable
Case 23 This case involved a 35-year-oldwoman with jaundice According to the BfArM(see Appendix 2) this patient also took parac-etamol but no dosage or details were providedThis case and case 25 in the BfArM listing ap-pear to be the same case Both cases have beenlabeled as possible by some authorities butgiven the lack of information about the dosageof paracetamol and the apparent confusion re-garding cases 23 and 25 we submit that theonly logical assessment is unassessable
Case 2627 This case involved a woman whowas either 38 or 39 yearsrsquo old with hepatitis Itappears that the two cases have been duplicated(Schmidt and Nahrstedt 2002) The confusionwith this case is another example of inaccuratedata provided by the BfArM Information re-garding these cases (or case) depending onwhether the two reports concern the samewoman is unclear Penicillin can be associatedwith hypersensitivity and cholestatic jaundicebut the information given is inadequate to makeany meaningful assessment For this reason weclass this case as unassessable
Case 29 This case involved a 60-year-oldwoman who had a liver transplant This womanwas taking piretamide (which is a loop diuretic)Frusemide another loop diuretic can be associ-ated with cholestatic jaundice According to theBfArM chart (see Appendix 2) she was also tak-ing a sympathomimetic drug etilefrin Thedosage of kava varied but was up to 480ndash1200mg per day (Schmidt and Nahrstedt 2002)which is up to ten times the German Commis-sion E maximum recommended dose (Blumen-thal 1998) Although some authorities have re-garded this case as possible in view of themarked overdosing of kava and the concomitantmedication this case can hardly be said to be areflection on the proper therapeutic use of kava
(5) Cases in which drugs not associated withliver damage herbal medicines or dietarysupplements or kavain alone were taken
This category had eight cases 2 78 11 1322 24 and 25
For these cases detail was limited and theBfArM did not implicate any other drugs ormedications (although this may not be thecase)
All patients in this group apart from the pa-tient in Case 78 for whom no information wasgiven were reported to have made full recov-eries In some of these cases it is not clearwhether the patients were ill or whether thesecases merely recorded raised liver-function en-zymes
Case 2 This case involved a 35-year-old manwith cholestatic hepatitis Concomitant med-ication was ldquounknownrdquo Apart from Cases 18and 30 this is the only case for which it is pos-sible that no other concomitant medication wastaken but there is a marked lack of informationfor this case As noted above this patient wastaking synthetic kavain not kava We regardthis case as unassessable
Case 5 This case involved a woman who waseither 68 or 69 yearsrsquo old with cholestatic he-patitis She was also taking a St Johnrsquos wort(Hypericum perforatum) product which hasbeen associated with CYP3A4 A biopsyshowed ldquoimmunologic hypersensitivityrdquo Thiscase may be regarded as possible but in viewof the immunologic hypersensitivity it maywell have been an idiosyncratic event that wasnot necessarily associated with kava usage
Case 78 This case involved a woman or twowomen ages 72 andor 75 with cholestatic he-patitis These two cases appear to be actuallyone case The woman was taking twoherbalvitamin products one of which in-cluded 06 mg of kavalactones Given the con-fusion involved these ldquocasesrdquo must be re-garded as unassessable
Case 11 This case involved a 59-year-oldwoman who was taking hyoscine butylbro-mide as a suppository Schmidt and Nahrstedt(2002) commented that according to additionalinformation obtained from the BfArM it is un-certain as to whether this patient was taking akava product at all We regard this case asunassessable
DENHAM ET AL246
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
Schulz noted that to create these concentratedstandardized extracts kava is dissolved in ahigh percentage of an ethanolndashwater mixtureto obtain extracts containing approximately30 kavalactones or alternatively using anacetonendashwater mixture to obtain extracts con-taining approximately 70 kavalactones Whit-ton Whitehouse and Evans (Appendix 1)make the same point about enhanced kavalac-tone extraction using a high ethanol or acetonemedium but detail somewhat different extrac-tion values Both types of products have a herb-to-extract ratio of approximately 12ndash201(Schulz 1997) The dosage recommended by theGerman Commission E is expressed as theequivalent of 60ndash120 mg of kavalactones per day(Blumenthal 1998)
The preparation methods used for stan-dardized products are highly technical and extraction rates vary (Kubatova et al 2001)depending on the solvents used and the tem-perature at which the products are preparedAs Whitton et al propose (Appendix 1) bothefficacy and safety may depend on thekavalactones remaining in their natural formsand on the extraction of the other natural con-stituents of the plant
Varying extraction techniques and preparationmethods may result in an unnatural variation inthe relative concentration of each lactone or inproduction artifacts that may be pathologic to theliver It should be noted that some commercialkava products may also contain syntheticracemic kavain that may have other characteris-tics than the naturally occurring product has Itis clear that these technical matters related to ex-traction techniques require further elucidation
Proponents of concentrated standardizedproducts assert that they provide an effectivedose within a consistent range The traditionalwater-based kava preparations of the Polyne-sian peoples and low-alcohol kava tincturesused by herbal practitioners have been consid-ered to be unreliable because the concentrationof active constituents is relatively low andvaries from kava batch to batch Howeverthere are four relevant counterarguments
(1) The whole range of the constituents mayproduce a more effective and safe medicine(Williamson 2001)
(2) Some constituents not necessarily consid-ered active may enhance the safety of themedicine (Appendix 1)
DENHAM ET AL240
OCH3
H3COyangonin
(+)-methysticin
O O
OCH3
demethoxyangonin
O O
OCH3
OO
OH
O
(+)-dihydromethysticin
OCH3
OO
OH
O
(+)-kavain
OCH3
OH
O
(+)-dihydrokavain
OCH3
OH
O
FIG 1 Kavapyrones of kava (Piper methysticum) Per Haberlein et al 1997
(3) Definitive isolation of the active constituentis elusive in other medicinal plants such asHypericum perforatum (McIntyre 2000Barnes et al 2001)
(4) Herbal practitioners rely on the synergy be-tween a whole range of constituents in theherb or herb within a herbal prescriptionwhich is individually prescribed for a pa-tient This positive interaction may alsohave the benefit of keeping levels of anyone constituent below the safety threshold
LOW-ALCOHOL TINCTURES
The Traditional Medicines Evaluation Com-mittee (TMEC) strongly advocates the use ofextraction techniques that closely approximatethose traditionally used in Polynesia Thiswould require the use of low-alcohol tincturesmade by the traditional cold macerationprocesses common to UK tincture makingThe reasons for this opinion are set out belowthey have also been explored by Whitton et al(Appendix 1)
Tinctures used by herbal practitioners areprepared by macerating dried kava in a mix-ture of water and ethanol It has been shownthat such extracts using 25 ethanol75 wa-ter contain up to 30 times fewer kavalactonesthan the concentrated standardized prepara-tions (Appendix 1) The traditional preparationmethod using a mixture of 25 ethanol75water extracts a wider range of the naturalkava constituents (Appendix 1)
DOSAGE AND OVERDOSAGE
Assuming a 15 25 tincture and an upperlimit of 20 kavalactones in the dried herb(concentrations stated as 3ndash20 see sectionon Pharmacology below) then 500 mL of theherb would contain (100 3 02 3 015) 5 3 g(3000 mg) of kavalactones In addition assum-ing a daily dosage of 5ndash10 mL of the 15 25tincture the daily dose of kavalactonesamounts to a maximum of 30ndash60 mg If the con-centration of kavalactones were lower for ex-ample at approximately 10 as appears to bethe case with regard to Australian kava dis-
cussed by Clough et al (2000) then this dosagefalls to 15ndash30 mg per day It is noteworthy thatthe maximum daily dosage here is equivalentto the minimum daily dosages of the 60ndash210mg kavalactones given in clinical trials of kavaconducted in Germany
Although standardized extracts provide ahigher dosage of kavalactones than low-alco-hol tinctures overdosage in itself is unlikelyto be the cause of hepatotoxicity Strong evi-dence for this is the fact that kava is takendaily at high doses as a normal part of dailylife in large areas of the South Pacific Indeedsome of the accounts of high kava intake areremarkable For example Chanwai (2000) de-scribed the case of a man who was admittedto a hospital after an overdose but ldquoslept offrdquohis symptoms and admitted to consuming upto 40 bowls of a kava preparation per day forthe last 14 years In Australia missionaries in-troduced kava to the aborigines in the 1980sas a substitute for alcohol and it is claimed thatthis has led to abuse of kava Clough et al(2000) discussed this concern and reviewedtwelve studies on the amount of kava usedThe researchers found that social setting ap-pears to determine the amount used with lonedrinkers consuming much more than peoplewho enjoy kava in a family group The re-searchers described normal use of kava in theNorthern Territory as being 37 g of kava pow-der (containing approximately 3800 mg ofkavalactones) per hour with heavy consumersusing approximately 610 g per week preparedas a drink The incidence of serious illness re-sulting from hepatotoxicity associated withregular kava usage would surely have beenobserved by the medical services in Polynesiaand Australia if overdosage of kavalactoneswere the main cause of hepatotoxicity
UNTOWARD EFFECTS
There is a justified concern in Europe thatidiosyncratic hepatotoxicity associated with us-ing some herbal medicines may not be identi-fied because the population that takes herbalmedicines is not large enough to produce suf-ficient cases for the association to be noted Butthe fact that kava remains in traditional usageto such a wide extent is a powerful argument
KAVA WORK-IN-PROGRESS 241
that idiosyncratic hepatotoxicity would havebeen noted
Two postmarketing observation studies inGermany each on more than 3000 people werecited by Pittler and Ernst (2000) in addition tothe abovementioned clinical trials In these ob-servational studies the rate of adverse eventswas 23 (with a daily dose of 120ndash240 mg ofkavalactones) and 15 (with a daily dose of105 mg of kavalactones) The most frequent ad-verse reports were gastrointestinal complaintsallergic skin reactions headaches and photo-sensitivity
There is evidence in the South Pacific of a char-acteristic kava-induced skin disease a scaly rashthat is suggestive of icthyosismdasha condition calledldquokava dermopathyrdquo (Ruze 1990) Although theskin becomes yellow the description does notsuggest an underlying hepatic condition in thatthe patient remains well the rash is not itchyand the condition is ameliorated without treat-ment if heavy use of kava is reduced
The German and Swiss reports cited by theBfArM are of concern because there have beenprevious reports of hepatotoxicity associatedwith the use of some medicinal plants (Larrey1997) The kava case reports from the BfArM(see Appendix 2) include all three of the mainforms of acute damage that can result from ad-verse drug reactions (1) necrosis (2) drug-in-duced hepatitis and (3) cholestatic hepatitis(Hodgson and Levi 1997) This suggests thatthere is a range of causes rather than just onecause in these cases The BfArM case reportshave been circulated worldwide and are cur-rently being evaluated by government agenciesin Europe Australia Canada the UnitedStates and elsewhere We have received anumber of informal case assessments fromthese sources that cannot be specifically citedbecause of their confidential status To achievetransparency and encourage a full debate aboutkava however the BfArM cases are evaluatedin the section entitled Discussion of Cases Re-ported by the BfArM
CRITERIA FOR ASSESSING THE CASE REPORTS
A recent review of the information availableon the case reports (Schmidt and Nahrstedt
2002) is supported by details of the case re-ports on the Web site of the University ofMuenster (wwwuni-muensterdechemiepbkavaanalysehtml)
The criteria for causality assessment of ad-verse reactions used are as follows (Edwardsand Aronson 2000)Probable is defined as
A clinical event including a laboratory testabnormality that occurs in a plausible timerelation to drug administration and that can-not be explained by coincidental or concur-rent disease or other drugs or chemicals
The response to withdrawal of the drug(dechallange) should be clinically plausible
The event must be definitive pharmacolog-ically or phenomenologically using a satis-factory rechallenge procedure if necessary
Possible is defined as
A clinical event including a laboratory testabnormality with a reasonable time relationto administration of the drug but that couldbe explained by concurrent disease or otherdrugs or chemicals
Information on drug withdrawal may belacking or unclear
Unlikely is defined as
A clinical event including a laboratory testabnormality with a temporal relation to theadministration of the drug which makes acausal relation improbable and in whichother drugs chemicals or underlying dis-ease provide plausible explanations
Unassessable is defined as
A report suggesting an adverse reaction thatcannot be judged because information is in-sufficient or contradictory and cannot besupplemented or verified
DISCUSSION OF CASES REPORTED BY THE BfArM
The cases discussed below are analyzed andcategorized by common factors of note withour own assessments
DENHAM ET AL242
(1) Cases of most concern
This group includes five cases 10 13 16 18and 28 According to the assessments made by various government agencies these casescause the most concern and are often cited asbeing probable For this reason these cases aredealt with first As discussed below mostmdashifnot allmdashof these cases have associated factorsthat put this probable categorization into ques-tion
Case 10 This case described necrotizing hep-atitis in a 39-year old female patient with pos-itive reexposure (Strahl et al 1998) During thefirst period that the kava product was takenan oral contraceptive and paroxetine were con-comitant medications It appears that paroxe-tine was not the only antidepressant taken bythis patient who also occasionally took StJohnrsquos wort (Hypericum perforatum) The Exec-utive Summary issued by the Bundesverbandder Arzneimittel Hersteller eV (BAH) andBundesverband der Pharmazeutischen Indus-trie eV (BP) (see Appendix 3) stated ldquoA causalrelationship with kava cannot be excluded butthe patientrsquos history and a potential preexistingliver damage must be taken into account In ad-dition the kava preparation used was not iden-tified by the physicianrdquo
Moreover in this case taking paroxetine incombination with an oral contraceptive maywell have led to overburdening the liver a sit-uation that could have been exacerbated by tak-ing a kava preparation Schmidt and Nahrstedt(2002) suggested that this case may be associ-ated with an immunologic reaction After re-viewing all of the cases in detail Schmidt andNahrstedt (2002) concluded that this is the onlycase for which there was sufficient informationto make an association with kava appear prob-able and for which the dose of kava also con-formed to that recommended by the Com-mission E monograph (Blumenthal 2000)However as discussed below Russmann et al(2001) tested this patient for CYP2D6 and as inCase 16 found this patient to be CYP2D6 defi-cient which appears to have made her partic-ularly vulnerable to the cocktail of drugs shewas taking Given the complicating features ofthis case we submit that this case should beclassed as possible rather than probable
Case 13 This was a case of a 62-year-oldwoman with jaundice The BfArM table (seeAppendix 2) noted regarding concomitantmedication that there was ldquonone denotedrdquo butit was claimed that concomitant medication didexist but was ldquounknownrdquo The insufficiency ofdata provided for this case was highlighted byBfArMrsquos warning note ldquoNo medical messagerdquoIn addition it should be noted that no detailsof the dosage of kava or period of its adminis-tration were apparently recorded for this caseThis is clearly insufficient information onwhich to base a probable assessment
Case 16 This case concerned a 33-year-oldwoman with jaundice The woman wasrecorded as having taken an overdose of alco-hol measured at 60 g (Russman et al 2001) andthen analgesics including paracetamol fol-lowing this alcohol binge Despite the massiveintake of alcohol a liver biopsy indicated thata drug rather than an alcohol induced toxicgenesis However this case like that of Case 10above was discussed by Russman et al (2001)who demonstrated afterward that this patientwas shown to be CYP2D6 deficient which (asdiscussed below) seems to be a risk factor forthe hepatotoxicity that was ascribed to kavaWe submit that given these circumstances thiscase should be considered possible rather thanprobable
Case 18 This case concerned a 50-year-oldman who had necrosis leading to a liver trans-plant This patient took a product manufac-tured by acetone extraction at a dose deliver-ing 210ndash280 mg of kavalactones per day for 15months ldquomoderate alcoholrdquo (ldquomoderaterdquo is notdefined by BfArM) evening primrose(Oenothera biennis) and a yeast preparationThe dosage of kava was well above the Ger-man Commission E recommended dose ofkavalactones (Blumenthal 1998) It was alsorecorded that 500ndash1000 mg of paracetamol wastaken by this patient shortly before transplan-tation The combination of paracetamol and al-cohol plus the very high dose of kava extractedin acetone taken by this man casts seriousdoubts on the assessment of probable in thiscase
Case 28 (BAH) This case concerned a
KAVA WORK-IN-PROGRESS 243
woman age unknown with hepatitis This caseis hard to assess because neither the patientrsquosage nor diagnosis was given and the womanwas taking eleven medications including estra-diol valerate acetylcysteine losartan (which israrely be associated with hepatitis) and mepra-zole (which can be associated with liver diseasealthough this is rare) Omeprazole is metabo-lized by the polymorphic CYP2C19 which is absent in 3 of Caucasians (Flockhart et al2000) The woman was also taking echinacea(Echinacea purpurea) and five products that ap-peared to be for upper respiratory problems Itshould be noted that this patient was taking syn-thetic kavain not kava A comment from BfArMconcerning this case noted ldquorecurrence of the he-patic side-effectsrdquo which has evidently been in-terpreted by some authorities as being equiva-lent to a ldquopositive rechallengerdquo Whether or notthis was actually so was not clear from the datasupplied It appears (Schmidt and Nahrstedt2002) that Case 28 has been published as twocases with slightly different details This is con-fusing and considering that the woman was tak-ing 11 other medications together with a syn-thetic kava (which we submit is not equivalentto natural kava) and that no diagnosis of hercondition was supplied this calls the assessmentof probable in this case into question
(2) Cases associated with taking synthetic kavain
In this category there were 4 cases 1 2 19and 28
In each of these cases the patients concernedwere taking a product made from synthetickavain Although the outcome was hepatitis inall four cases kavain cannot be equated withthe naturally occurring form of kava whichcontains many other constituents that may playan important role in ensuring the safety of thisherb Therefore we submit that no inferenceshould be drawn from these cases Traditionalusage should not be taken as evidence for safeusage of synthetic products
(3) Patients who were taking oral contraceptivepills or hormone replacement therapy (HRT)together with drugs that can also be associatedwith liver damage
The cases in this category were 4 10 12 2021 and 28
Cholestatic jaundice associated with use ofestrogen-containing medications is extremelyrare (Lindberg 1992) but does occur In these6 cases the women were also taking drugs thatcan also be associated with jaundice
Case 4 This case involved a 39-year-oldwoman with jaundice She was on diazepam10 mg PRN for 6 months Some authoritiescalled this case possible Our assessment is thatthe case is unassessable
Case 10 This case involved a 39-year-oldwoman with necrotizing hepatitis For a de-tailed assessment see above
Case 12 This case involved a 37-year-oldwoman with hepatitis She was on 150 mg ofdiclofenac via intramuscular injection Hepato-toxic reactions associated with nonsteroidalanti-inflammatory drug use are extremely rareand concomitant exposure to other hepatotoxicdrugs is considered to be an important factor(Bareille et al 2001) This case of hepatitis isdifficult to interpret because it occurred inBrazil and because ldquoreexposure was said to benegative for all three drugsrdquo We regard thiscase as unassessable
Case 20 This case involved 50-year-oldwoman with necrosis who had a liver trans-plant She had a 20-year history of combinedoral contraceptive use but had changed monthsearlier to estradiol valerate (which was appar-ently taken alone) as HRT She had also startedglimepiride 8 months earlier This is used fortreating type II diabetes and is rarely associatedwith cholestatic jaundice and liver failure Weregard this case as unlikely
Case 21 This case involved a 22-year-oldwoman with necrosis who had a liver trans-plant This woman had changed from Valette(Jenapharm GmbH Jena Germany) (2 mg ofdienogest and 003 mg of ethinlestradiol) toPramino (180215250 mcg of norgestimateand mcg 25 of ethinylestradiol) She also tookrizatriptan if required for migraine reliefRizatriptan should be used with caution in he-patic impairment and avoided if a patient hassevere liver disease Some authorities considerthis case as being possible but our assessment
DENHAM ET AL244
is in view of the other medications taken isthat this case is unassessable
Case 28 This case involved a woman age un-known with hepatitis This case is discussed atlength above As noted above this patient wastaking synthetic kavain not kava
(4) Patients who were taking drugs that can beassociated with liver damage
There were ten cases in this category 1 6 914 15 17 19 23 2627 and 29
Case 1 This case involved a woman age 69with cholestatic hepatitis She was taking pen-toxifylline (which can be associated with intra-hepatic cholestasis) and a diuretic including thepotassium-sparing triamterene (which can beassociated with jaundice) As noted above thispatient was taking synthetic kavain not kavaWe consider this case unassessable
Case 6 This case involved a woman age 50with hepatitis She was taking frusemide(which can be associated with cholestatic jaun-dice) triamterene atenolol and a large dose ofterfenadine (300 mg) The recommended doseof terfenadine in the British National Formu-lary (March 2001) is 60ndash120 mg The Formularyrecommends avoiding this drug in patientswho have hepatic impairment and also says toldquoavoid concomitant administration of drugs li-able to produce electrolyte imbalance such asdiureticsrdquo (British National Formulary 2001)Despite this warning this woman was also tak-ing the diuretic frusemide The InterkantonalenKontrollstelle der Schweiz of Switzerland con-sidered this case of hepatitis to be caused byterfenadine And although some authoritiesregard this case as possible our assessment isthat this case is unlikely
Case 9 This case involved an 81-year-oldwoman who had liver failure and subsequentdeath She was taking hydrochlorothiazide(which can occasionally be associated with in-trahepatic cholestasis) However according toSchmidt and Nahrstedt (2002) there was evi-dence of chronic alcohol abuse and they re-ported that the autopsy showed chronic pan-creatitis that was characteristic of alcoholabuse The autopsy report (Schmidt and
Nahrstedt 2002) apparently said that thesymptoms must have occurred over a periodof at least 18 months The report conceded thatldquohepatic impairment by alcohol [was] not ex-cludedrdquo In these circumstances it seems en-tirely reasonable to claim that this case is un-related to kava use We regard this case asunlikely
Case 14 This case involved a 33-year-oldwoman with hepatitis Cisapride may havebeen taken (which can cause reversible changesthat show in liver-function tests) Cirrhosis ina woman of 33 is an unexplained finding andthe detail in this case is inadequate to elucidateit We consider this case to be unassessable
Case 15 This case involved a 46-year-oldwoman with jaundice She had been taking hy-drochlorothiazide (which can be associatedwith intrahepatic cholestasis) for 55 monthsplus 80 mg of valsartan and 80 mg ofpropanolol per day Some authorities regardthis case as possible but we consider it to beunassessable
Case 17 This case involved a 59-year-oldwoman with jaundice She had taken 100ndash200mg of celecoxib a cyclo-oxygenase-2 inhibitorper day According to the criteria for causalityassessment of adverse reactions some author-ities consider this case to be possible but our as-sessment is that it is unassessable
Case 19 This case involved a 21-year-oldwoman with hepatitis She was taking panto-prazole (which as with omeprazole can be as-sociated with liver disease) She was also takingparacetamol and metoclopramide and had over-dosed on kavain More detail is needed on othermedical conditions suffered by this patient in or-der to interpret this case It is suggested bySchmidt that this woman was using up to 10tablets per day of the product (the recom-mended dose is up to 6 tablets per day) and thatthere was apparently a discussion in her med-ical record file that she may also have used Ec-stasy (substance that has been associated with
KAVA WORK-IN-PROGRESS 245
Personal communication from M McGuffin to M McIn-tyre available as an online document at ehpaglobalnetcouk
fulminant hepatic failure) This case appears tobe unassessable
Case 23 This case involved a 35-year-oldwoman with jaundice According to the BfArM(see Appendix 2) this patient also took parac-etamol but no dosage or details were providedThis case and case 25 in the BfArM listing ap-pear to be the same case Both cases have beenlabeled as possible by some authorities butgiven the lack of information about the dosageof paracetamol and the apparent confusion re-garding cases 23 and 25 we submit that theonly logical assessment is unassessable
Case 2627 This case involved a woman whowas either 38 or 39 yearsrsquo old with hepatitis Itappears that the two cases have been duplicated(Schmidt and Nahrstedt 2002) The confusionwith this case is another example of inaccuratedata provided by the BfArM Information re-garding these cases (or case) depending onwhether the two reports concern the samewoman is unclear Penicillin can be associatedwith hypersensitivity and cholestatic jaundicebut the information given is inadequate to makeany meaningful assessment For this reason weclass this case as unassessable
Case 29 This case involved a 60-year-oldwoman who had a liver transplant This womanwas taking piretamide (which is a loop diuretic)Frusemide another loop diuretic can be associ-ated with cholestatic jaundice According to theBfArM chart (see Appendix 2) she was also tak-ing a sympathomimetic drug etilefrin Thedosage of kava varied but was up to 480ndash1200mg per day (Schmidt and Nahrstedt 2002)which is up to ten times the German Commis-sion E maximum recommended dose (Blumen-thal 1998) Although some authorities have re-garded this case as possible in view of themarked overdosing of kava and the concomitantmedication this case can hardly be said to be areflection on the proper therapeutic use of kava
(5) Cases in which drugs not associated withliver damage herbal medicines or dietarysupplements or kavain alone were taken
This category had eight cases 2 78 11 1322 24 and 25
For these cases detail was limited and theBfArM did not implicate any other drugs ormedications (although this may not be thecase)
All patients in this group apart from the pa-tient in Case 78 for whom no information wasgiven were reported to have made full recov-eries In some of these cases it is not clearwhether the patients were ill or whether thesecases merely recorded raised liver-function en-zymes
Case 2 This case involved a 35-year-old manwith cholestatic hepatitis Concomitant med-ication was ldquounknownrdquo Apart from Cases 18and 30 this is the only case for which it is pos-sible that no other concomitant medication wastaken but there is a marked lack of informationfor this case As noted above this patient wastaking synthetic kavain not kava We regardthis case as unassessable
Case 5 This case involved a woman who waseither 68 or 69 yearsrsquo old with cholestatic he-patitis She was also taking a St Johnrsquos wort(Hypericum perforatum) product which hasbeen associated with CYP3A4 A biopsyshowed ldquoimmunologic hypersensitivityrdquo Thiscase may be regarded as possible but in viewof the immunologic hypersensitivity it maywell have been an idiosyncratic event that wasnot necessarily associated with kava usage
Case 78 This case involved a woman or twowomen ages 72 andor 75 with cholestatic he-patitis These two cases appear to be actuallyone case The woman was taking twoherbalvitamin products one of which in-cluded 06 mg of kavalactones Given the con-fusion involved these ldquocasesrdquo must be re-garded as unassessable
Case 11 This case involved a 59-year-oldwoman who was taking hyoscine butylbro-mide as a suppository Schmidt and Nahrstedt(2002) commented that according to additionalinformation obtained from the BfArM it is un-certain as to whether this patient was taking akava product at all We regard this case asunassessable
DENHAM ET AL246
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
(3) Definitive isolation of the active constituentis elusive in other medicinal plants such asHypericum perforatum (McIntyre 2000Barnes et al 2001)
(4) Herbal practitioners rely on the synergy be-tween a whole range of constituents in theherb or herb within a herbal prescriptionwhich is individually prescribed for a pa-tient This positive interaction may alsohave the benefit of keeping levels of anyone constituent below the safety threshold
LOW-ALCOHOL TINCTURES
The Traditional Medicines Evaluation Com-mittee (TMEC) strongly advocates the use ofextraction techniques that closely approximatethose traditionally used in Polynesia Thiswould require the use of low-alcohol tincturesmade by the traditional cold macerationprocesses common to UK tincture makingThe reasons for this opinion are set out belowthey have also been explored by Whitton et al(Appendix 1)
Tinctures used by herbal practitioners areprepared by macerating dried kava in a mix-ture of water and ethanol It has been shownthat such extracts using 25 ethanol75 wa-ter contain up to 30 times fewer kavalactonesthan the concentrated standardized prepara-tions (Appendix 1) The traditional preparationmethod using a mixture of 25 ethanol75water extracts a wider range of the naturalkava constituents (Appendix 1)
DOSAGE AND OVERDOSAGE
Assuming a 15 25 tincture and an upperlimit of 20 kavalactones in the dried herb(concentrations stated as 3ndash20 see sectionon Pharmacology below) then 500 mL of theherb would contain (100 3 02 3 015) 5 3 g(3000 mg) of kavalactones In addition assum-ing a daily dosage of 5ndash10 mL of the 15 25tincture the daily dose of kavalactonesamounts to a maximum of 30ndash60 mg If the con-centration of kavalactones were lower for ex-ample at approximately 10 as appears to bethe case with regard to Australian kava dis-
cussed by Clough et al (2000) then this dosagefalls to 15ndash30 mg per day It is noteworthy thatthe maximum daily dosage here is equivalentto the minimum daily dosages of the 60ndash210mg kavalactones given in clinical trials of kavaconducted in Germany
Although standardized extracts provide ahigher dosage of kavalactones than low-alco-hol tinctures overdosage in itself is unlikelyto be the cause of hepatotoxicity Strong evi-dence for this is the fact that kava is takendaily at high doses as a normal part of dailylife in large areas of the South Pacific Indeedsome of the accounts of high kava intake areremarkable For example Chanwai (2000) de-scribed the case of a man who was admittedto a hospital after an overdose but ldquoslept offrdquohis symptoms and admitted to consuming upto 40 bowls of a kava preparation per day forthe last 14 years In Australia missionaries in-troduced kava to the aborigines in the 1980sas a substitute for alcohol and it is claimed thatthis has led to abuse of kava Clough et al(2000) discussed this concern and reviewedtwelve studies on the amount of kava usedThe researchers found that social setting ap-pears to determine the amount used with lonedrinkers consuming much more than peoplewho enjoy kava in a family group The re-searchers described normal use of kava in theNorthern Territory as being 37 g of kava pow-der (containing approximately 3800 mg ofkavalactones) per hour with heavy consumersusing approximately 610 g per week preparedas a drink The incidence of serious illness re-sulting from hepatotoxicity associated withregular kava usage would surely have beenobserved by the medical services in Polynesiaand Australia if overdosage of kavalactoneswere the main cause of hepatotoxicity
UNTOWARD EFFECTS
There is a justified concern in Europe thatidiosyncratic hepatotoxicity associated with us-ing some herbal medicines may not be identi-fied because the population that takes herbalmedicines is not large enough to produce suf-ficient cases for the association to be noted Butthe fact that kava remains in traditional usageto such a wide extent is a powerful argument
KAVA WORK-IN-PROGRESS 241
that idiosyncratic hepatotoxicity would havebeen noted
Two postmarketing observation studies inGermany each on more than 3000 people werecited by Pittler and Ernst (2000) in addition tothe abovementioned clinical trials In these ob-servational studies the rate of adverse eventswas 23 (with a daily dose of 120ndash240 mg ofkavalactones) and 15 (with a daily dose of105 mg of kavalactones) The most frequent ad-verse reports were gastrointestinal complaintsallergic skin reactions headaches and photo-sensitivity
There is evidence in the South Pacific of a char-acteristic kava-induced skin disease a scaly rashthat is suggestive of icthyosismdasha condition calledldquokava dermopathyrdquo (Ruze 1990) Although theskin becomes yellow the description does notsuggest an underlying hepatic condition in thatthe patient remains well the rash is not itchyand the condition is ameliorated without treat-ment if heavy use of kava is reduced
The German and Swiss reports cited by theBfArM are of concern because there have beenprevious reports of hepatotoxicity associatedwith the use of some medicinal plants (Larrey1997) The kava case reports from the BfArM(see Appendix 2) include all three of the mainforms of acute damage that can result from ad-verse drug reactions (1) necrosis (2) drug-in-duced hepatitis and (3) cholestatic hepatitis(Hodgson and Levi 1997) This suggests thatthere is a range of causes rather than just onecause in these cases The BfArM case reportshave been circulated worldwide and are cur-rently being evaluated by government agenciesin Europe Australia Canada the UnitedStates and elsewhere We have received anumber of informal case assessments fromthese sources that cannot be specifically citedbecause of their confidential status To achievetransparency and encourage a full debate aboutkava however the BfArM cases are evaluatedin the section entitled Discussion of Cases Re-ported by the BfArM
CRITERIA FOR ASSESSING THE CASE REPORTS
A recent review of the information availableon the case reports (Schmidt and Nahrstedt
2002) is supported by details of the case re-ports on the Web site of the University ofMuenster (wwwuni-muensterdechemiepbkavaanalysehtml)
The criteria for causality assessment of ad-verse reactions used are as follows (Edwardsand Aronson 2000)Probable is defined as
A clinical event including a laboratory testabnormality that occurs in a plausible timerelation to drug administration and that can-not be explained by coincidental or concur-rent disease or other drugs or chemicals
The response to withdrawal of the drug(dechallange) should be clinically plausible
The event must be definitive pharmacolog-ically or phenomenologically using a satis-factory rechallenge procedure if necessary
Possible is defined as
A clinical event including a laboratory testabnormality with a reasonable time relationto administration of the drug but that couldbe explained by concurrent disease or otherdrugs or chemicals
Information on drug withdrawal may belacking or unclear
Unlikely is defined as
A clinical event including a laboratory testabnormality with a temporal relation to theadministration of the drug which makes acausal relation improbable and in whichother drugs chemicals or underlying dis-ease provide plausible explanations
Unassessable is defined as
A report suggesting an adverse reaction thatcannot be judged because information is in-sufficient or contradictory and cannot besupplemented or verified
DISCUSSION OF CASES REPORTED BY THE BfArM
The cases discussed below are analyzed andcategorized by common factors of note withour own assessments
DENHAM ET AL242
(1) Cases of most concern
This group includes five cases 10 13 16 18and 28 According to the assessments made by various government agencies these casescause the most concern and are often cited asbeing probable For this reason these cases aredealt with first As discussed below mostmdashifnot allmdashof these cases have associated factorsthat put this probable categorization into ques-tion
Case 10 This case described necrotizing hep-atitis in a 39-year old female patient with pos-itive reexposure (Strahl et al 1998) During thefirst period that the kava product was takenan oral contraceptive and paroxetine were con-comitant medications It appears that paroxe-tine was not the only antidepressant taken bythis patient who also occasionally took StJohnrsquos wort (Hypericum perforatum) The Exec-utive Summary issued by the Bundesverbandder Arzneimittel Hersteller eV (BAH) andBundesverband der Pharmazeutischen Indus-trie eV (BP) (see Appendix 3) stated ldquoA causalrelationship with kava cannot be excluded butthe patientrsquos history and a potential preexistingliver damage must be taken into account In ad-dition the kava preparation used was not iden-tified by the physicianrdquo
Moreover in this case taking paroxetine incombination with an oral contraceptive maywell have led to overburdening the liver a sit-uation that could have been exacerbated by tak-ing a kava preparation Schmidt and Nahrstedt(2002) suggested that this case may be associ-ated with an immunologic reaction After re-viewing all of the cases in detail Schmidt andNahrstedt (2002) concluded that this is the onlycase for which there was sufficient informationto make an association with kava appear prob-able and for which the dose of kava also con-formed to that recommended by the Com-mission E monograph (Blumenthal 2000)However as discussed below Russmann et al(2001) tested this patient for CYP2D6 and as inCase 16 found this patient to be CYP2D6 defi-cient which appears to have made her partic-ularly vulnerable to the cocktail of drugs shewas taking Given the complicating features ofthis case we submit that this case should beclassed as possible rather than probable
Case 13 This was a case of a 62-year-oldwoman with jaundice The BfArM table (seeAppendix 2) noted regarding concomitantmedication that there was ldquonone denotedrdquo butit was claimed that concomitant medication didexist but was ldquounknownrdquo The insufficiency ofdata provided for this case was highlighted byBfArMrsquos warning note ldquoNo medical messagerdquoIn addition it should be noted that no detailsof the dosage of kava or period of its adminis-tration were apparently recorded for this caseThis is clearly insufficient information onwhich to base a probable assessment
Case 16 This case concerned a 33-year-oldwoman with jaundice The woman wasrecorded as having taken an overdose of alco-hol measured at 60 g (Russman et al 2001) andthen analgesics including paracetamol fol-lowing this alcohol binge Despite the massiveintake of alcohol a liver biopsy indicated thata drug rather than an alcohol induced toxicgenesis However this case like that of Case 10above was discussed by Russman et al (2001)who demonstrated afterward that this patientwas shown to be CYP2D6 deficient which (asdiscussed below) seems to be a risk factor forthe hepatotoxicity that was ascribed to kavaWe submit that given these circumstances thiscase should be considered possible rather thanprobable
Case 18 This case concerned a 50-year-oldman who had necrosis leading to a liver trans-plant This patient took a product manufac-tured by acetone extraction at a dose deliver-ing 210ndash280 mg of kavalactones per day for 15months ldquomoderate alcoholrdquo (ldquomoderaterdquo is notdefined by BfArM) evening primrose(Oenothera biennis) and a yeast preparationThe dosage of kava was well above the Ger-man Commission E recommended dose ofkavalactones (Blumenthal 1998) It was alsorecorded that 500ndash1000 mg of paracetamol wastaken by this patient shortly before transplan-tation The combination of paracetamol and al-cohol plus the very high dose of kava extractedin acetone taken by this man casts seriousdoubts on the assessment of probable in thiscase
Case 28 (BAH) This case concerned a
KAVA WORK-IN-PROGRESS 243
woman age unknown with hepatitis This caseis hard to assess because neither the patientrsquosage nor diagnosis was given and the womanwas taking eleven medications including estra-diol valerate acetylcysteine losartan (which israrely be associated with hepatitis) and mepra-zole (which can be associated with liver diseasealthough this is rare) Omeprazole is metabo-lized by the polymorphic CYP2C19 which is absent in 3 of Caucasians (Flockhart et al2000) The woman was also taking echinacea(Echinacea purpurea) and five products that ap-peared to be for upper respiratory problems Itshould be noted that this patient was taking syn-thetic kavain not kava A comment from BfArMconcerning this case noted ldquorecurrence of the he-patic side-effectsrdquo which has evidently been in-terpreted by some authorities as being equiva-lent to a ldquopositive rechallengerdquo Whether or notthis was actually so was not clear from the datasupplied It appears (Schmidt and Nahrstedt2002) that Case 28 has been published as twocases with slightly different details This is con-fusing and considering that the woman was tak-ing 11 other medications together with a syn-thetic kava (which we submit is not equivalentto natural kava) and that no diagnosis of hercondition was supplied this calls the assessmentof probable in this case into question
(2) Cases associated with taking synthetic kavain
In this category there were 4 cases 1 2 19and 28
In each of these cases the patients concernedwere taking a product made from synthetickavain Although the outcome was hepatitis inall four cases kavain cannot be equated withthe naturally occurring form of kava whichcontains many other constituents that may playan important role in ensuring the safety of thisherb Therefore we submit that no inferenceshould be drawn from these cases Traditionalusage should not be taken as evidence for safeusage of synthetic products
(3) Patients who were taking oral contraceptivepills or hormone replacement therapy (HRT)together with drugs that can also be associatedwith liver damage
The cases in this category were 4 10 12 2021 and 28
Cholestatic jaundice associated with use ofestrogen-containing medications is extremelyrare (Lindberg 1992) but does occur In these6 cases the women were also taking drugs thatcan also be associated with jaundice
Case 4 This case involved a 39-year-oldwoman with jaundice She was on diazepam10 mg PRN for 6 months Some authoritiescalled this case possible Our assessment is thatthe case is unassessable
Case 10 This case involved a 39-year-oldwoman with necrotizing hepatitis For a de-tailed assessment see above
Case 12 This case involved a 37-year-oldwoman with hepatitis She was on 150 mg ofdiclofenac via intramuscular injection Hepato-toxic reactions associated with nonsteroidalanti-inflammatory drug use are extremely rareand concomitant exposure to other hepatotoxicdrugs is considered to be an important factor(Bareille et al 2001) This case of hepatitis isdifficult to interpret because it occurred inBrazil and because ldquoreexposure was said to benegative for all three drugsrdquo We regard thiscase as unassessable
Case 20 This case involved 50-year-oldwoman with necrosis who had a liver trans-plant She had a 20-year history of combinedoral contraceptive use but had changed monthsearlier to estradiol valerate (which was appar-ently taken alone) as HRT She had also startedglimepiride 8 months earlier This is used fortreating type II diabetes and is rarely associatedwith cholestatic jaundice and liver failure Weregard this case as unlikely
Case 21 This case involved a 22-year-oldwoman with necrosis who had a liver trans-plant This woman had changed from Valette(Jenapharm GmbH Jena Germany) (2 mg ofdienogest and 003 mg of ethinlestradiol) toPramino (180215250 mcg of norgestimateand mcg 25 of ethinylestradiol) She also tookrizatriptan if required for migraine reliefRizatriptan should be used with caution in he-patic impairment and avoided if a patient hassevere liver disease Some authorities considerthis case as being possible but our assessment
DENHAM ET AL244
is in view of the other medications taken isthat this case is unassessable
Case 28 This case involved a woman age un-known with hepatitis This case is discussed atlength above As noted above this patient wastaking synthetic kavain not kava
(4) Patients who were taking drugs that can beassociated with liver damage
There were ten cases in this category 1 6 914 15 17 19 23 2627 and 29
Case 1 This case involved a woman age 69with cholestatic hepatitis She was taking pen-toxifylline (which can be associated with intra-hepatic cholestasis) and a diuretic including thepotassium-sparing triamterene (which can beassociated with jaundice) As noted above thispatient was taking synthetic kavain not kavaWe consider this case unassessable
Case 6 This case involved a woman age 50with hepatitis She was taking frusemide(which can be associated with cholestatic jaun-dice) triamterene atenolol and a large dose ofterfenadine (300 mg) The recommended doseof terfenadine in the British National Formu-lary (March 2001) is 60ndash120 mg The Formularyrecommends avoiding this drug in patientswho have hepatic impairment and also says toldquoavoid concomitant administration of drugs li-able to produce electrolyte imbalance such asdiureticsrdquo (British National Formulary 2001)Despite this warning this woman was also tak-ing the diuretic frusemide The InterkantonalenKontrollstelle der Schweiz of Switzerland con-sidered this case of hepatitis to be caused byterfenadine And although some authoritiesregard this case as possible our assessment isthat this case is unlikely
Case 9 This case involved an 81-year-oldwoman who had liver failure and subsequentdeath She was taking hydrochlorothiazide(which can occasionally be associated with in-trahepatic cholestasis) However according toSchmidt and Nahrstedt (2002) there was evi-dence of chronic alcohol abuse and they re-ported that the autopsy showed chronic pan-creatitis that was characteristic of alcoholabuse The autopsy report (Schmidt and
Nahrstedt 2002) apparently said that thesymptoms must have occurred over a periodof at least 18 months The report conceded thatldquohepatic impairment by alcohol [was] not ex-cludedrdquo In these circumstances it seems en-tirely reasonable to claim that this case is un-related to kava use We regard this case asunlikely
Case 14 This case involved a 33-year-oldwoman with hepatitis Cisapride may havebeen taken (which can cause reversible changesthat show in liver-function tests) Cirrhosis ina woman of 33 is an unexplained finding andthe detail in this case is inadequate to elucidateit We consider this case to be unassessable
Case 15 This case involved a 46-year-oldwoman with jaundice She had been taking hy-drochlorothiazide (which can be associatedwith intrahepatic cholestasis) for 55 monthsplus 80 mg of valsartan and 80 mg ofpropanolol per day Some authorities regardthis case as possible but we consider it to beunassessable
Case 17 This case involved a 59-year-oldwoman with jaundice She had taken 100ndash200mg of celecoxib a cyclo-oxygenase-2 inhibitorper day According to the criteria for causalityassessment of adverse reactions some author-ities consider this case to be possible but our as-sessment is that it is unassessable
Case 19 This case involved a 21-year-oldwoman with hepatitis She was taking panto-prazole (which as with omeprazole can be as-sociated with liver disease) She was also takingparacetamol and metoclopramide and had over-dosed on kavain More detail is needed on othermedical conditions suffered by this patient in or-der to interpret this case It is suggested bySchmidt that this woman was using up to 10tablets per day of the product (the recom-mended dose is up to 6 tablets per day) and thatthere was apparently a discussion in her med-ical record file that she may also have used Ec-stasy (substance that has been associated with
KAVA WORK-IN-PROGRESS 245
Personal communication from M McGuffin to M McIn-tyre available as an online document at ehpaglobalnetcouk
fulminant hepatic failure) This case appears tobe unassessable
Case 23 This case involved a 35-year-oldwoman with jaundice According to the BfArM(see Appendix 2) this patient also took parac-etamol but no dosage or details were providedThis case and case 25 in the BfArM listing ap-pear to be the same case Both cases have beenlabeled as possible by some authorities butgiven the lack of information about the dosageof paracetamol and the apparent confusion re-garding cases 23 and 25 we submit that theonly logical assessment is unassessable
Case 2627 This case involved a woman whowas either 38 or 39 yearsrsquo old with hepatitis Itappears that the two cases have been duplicated(Schmidt and Nahrstedt 2002) The confusionwith this case is another example of inaccuratedata provided by the BfArM Information re-garding these cases (or case) depending onwhether the two reports concern the samewoman is unclear Penicillin can be associatedwith hypersensitivity and cholestatic jaundicebut the information given is inadequate to makeany meaningful assessment For this reason weclass this case as unassessable
Case 29 This case involved a 60-year-oldwoman who had a liver transplant This womanwas taking piretamide (which is a loop diuretic)Frusemide another loop diuretic can be associ-ated with cholestatic jaundice According to theBfArM chart (see Appendix 2) she was also tak-ing a sympathomimetic drug etilefrin Thedosage of kava varied but was up to 480ndash1200mg per day (Schmidt and Nahrstedt 2002)which is up to ten times the German Commis-sion E maximum recommended dose (Blumen-thal 1998) Although some authorities have re-garded this case as possible in view of themarked overdosing of kava and the concomitantmedication this case can hardly be said to be areflection on the proper therapeutic use of kava
(5) Cases in which drugs not associated withliver damage herbal medicines or dietarysupplements or kavain alone were taken
This category had eight cases 2 78 11 1322 24 and 25
For these cases detail was limited and theBfArM did not implicate any other drugs ormedications (although this may not be thecase)
All patients in this group apart from the pa-tient in Case 78 for whom no information wasgiven were reported to have made full recov-eries In some of these cases it is not clearwhether the patients were ill or whether thesecases merely recorded raised liver-function en-zymes
Case 2 This case involved a 35-year-old manwith cholestatic hepatitis Concomitant med-ication was ldquounknownrdquo Apart from Cases 18and 30 this is the only case for which it is pos-sible that no other concomitant medication wastaken but there is a marked lack of informationfor this case As noted above this patient wastaking synthetic kavain not kava We regardthis case as unassessable
Case 5 This case involved a woman who waseither 68 or 69 yearsrsquo old with cholestatic he-patitis She was also taking a St Johnrsquos wort(Hypericum perforatum) product which hasbeen associated with CYP3A4 A biopsyshowed ldquoimmunologic hypersensitivityrdquo Thiscase may be regarded as possible but in viewof the immunologic hypersensitivity it maywell have been an idiosyncratic event that wasnot necessarily associated with kava usage
Case 78 This case involved a woman or twowomen ages 72 andor 75 with cholestatic he-patitis These two cases appear to be actuallyone case The woman was taking twoherbalvitamin products one of which in-cluded 06 mg of kavalactones Given the con-fusion involved these ldquocasesrdquo must be re-garded as unassessable
Case 11 This case involved a 59-year-oldwoman who was taking hyoscine butylbro-mide as a suppository Schmidt and Nahrstedt(2002) commented that according to additionalinformation obtained from the BfArM it is un-certain as to whether this patient was taking akava product at all We regard this case asunassessable
DENHAM ET AL246
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
that idiosyncratic hepatotoxicity would havebeen noted
Two postmarketing observation studies inGermany each on more than 3000 people werecited by Pittler and Ernst (2000) in addition tothe abovementioned clinical trials In these ob-servational studies the rate of adverse eventswas 23 (with a daily dose of 120ndash240 mg ofkavalactones) and 15 (with a daily dose of105 mg of kavalactones) The most frequent ad-verse reports were gastrointestinal complaintsallergic skin reactions headaches and photo-sensitivity
There is evidence in the South Pacific of a char-acteristic kava-induced skin disease a scaly rashthat is suggestive of icthyosismdasha condition calledldquokava dermopathyrdquo (Ruze 1990) Although theskin becomes yellow the description does notsuggest an underlying hepatic condition in thatthe patient remains well the rash is not itchyand the condition is ameliorated without treat-ment if heavy use of kava is reduced
The German and Swiss reports cited by theBfArM are of concern because there have beenprevious reports of hepatotoxicity associatedwith the use of some medicinal plants (Larrey1997) The kava case reports from the BfArM(see Appendix 2) include all three of the mainforms of acute damage that can result from ad-verse drug reactions (1) necrosis (2) drug-in-duced hepatitis and (3) cholestatic hepatitis(Hodgson and Levi 1997) This suggests thatthere is a range of causes rather than just onecause in these cases The BfArM case reportshave been circulated worldwide and are cur-rently being evaluated by government agenciesin Europe Australia Canada the UnitedStates and elsewhere We have received anumber of informal case assessments fromthese sources that cannot be specifically citedbecause of their confidential status To achievetransparency and encourage a full debate aboutkava however the BfArM cases are evaluatedin the section entitled Discussion of Cases Re-ported by the BfArM
CRITERIA FOR ASSESSING THE CASE REPORTS
A recent review of the information availableon the case reports (Schmidt and Nahrstedt
2002) is supported by details of the case re-ports on the Web site of the University ofMuenster (wwwuni-muensterdechemiepbkavaanalysehtml)
The criteria for causality assessment of ad-verse reactions used are as follows (Edwardsand Aronson 2000)Probable is defined as
A clinical event including a laboratory testabnormality that occurs in a plausible timerelation to drug administration and that can-not be explained by coincidental or concur-rent disease or other drugs or chemicals
The response to withdrawal of the drug(dechallange) should be clinically plausible
The event must be definitive pharmacolog-ically or phenomenologically using a satis-factory rechallenge procedure if necessary
Possible is defined as
A clinical event including a laboratory testabnormality with a reasonable time relationto administration of the drug but that couldbe explained by concurrent disease or otherdrugs or chemicals
Information on drug withdrawal may belacking or unclear
Unlikely is defined as
A clinical event including a laboratory testabnormality with a temporal relation to theadministration of the drug which makes acausal relation improbable and in whichother drugs chemicals or underlying dis-ease provide plausible explanations
Unassessable is defined as
A report suggesting an adverse reaction thatcannot be judged because information is in-sufficient or contradictory and cannot besupplemented or verified
DISCUSSION OF CASES REPORTED BY THE BfArM
The cases discussed below are analyzed andcategorized by common factors of note withour own assessments
DENHAM ET AL242
(1) Cases of most concern
This group includes five cases 10 13 16 18and 28 According to the assessments made by various government agencies these casescause the most concern and are often cited asbeing probable For this reason these cases aredealt with first As discussed below mostmdashifnot allmdashof these cases have associated factorsthat put this probable categorization into ques-tion
Case 10 This case described necrotizing hep-atitis in a 39-year old female patient with pos-itive reexposure (Strahl et al 1998) During thefirst period that the kava product was takenan oral contraceptive and paroxetine were con-comitant medications It appears that paroxe-tine was not the only antidepressant taken bythis patient who also occasionally took StJohnrsquos wort (Hypericum perforatum) The Exec-utive Summary issued by the Bundesverbandder Arzneimittel Hersteller eV (BAH) andBundesverband der Pharmazeutischen Indus-trie eV (BP) (see Appendix 3) stated ldquoA causalrelationship with kava cannot be excluded butthe patientrsquos history and a potential preexistingliver damage must be taken into account In ad-dition the kava preparation used was not iden-tified by the physicianrdquo
Moreover in this case taking paroxetine incombination with an oral contraceptive maywell have led to overburdening the liver a sit-uation that could have been exacerbated by tak-ing a kava preparation Schmidt and Nahrstedt(2002) suggested that this case may be associ-ated with an immunologic reaction After re-viewing all of the cases in detail Schmidt andNahrstedt (2002) concluded that this is the onlycase for which there was sufficient informationto make an association with kava appear prob-able and for which the dose of kava also con-formed to that recommended by the Com-mission E monograph (Blumenthal 2000)However as discussed below Russmann et al(2001) tested this patient for CYP2D6 and as inCase 16 found this patient to be CYP2D6 defi-cient which appears to have made her partic-ularly vulnerable to the cocktail of drugs shewas taking Given the complicating features ofthis case we submit that this case should beclassed as possible rather than probable
Case 13 This was a case of a 62-year-oldwoman with jaundice The BfArM table (seeAppendix 2) noted regarding concomitantmedication that there was ldquonone denotedrdquo butit was claimed that concomitant medication didexist but was ldquounknownrdquo The insufficiency ofdata provided for this case was highlighted byBfArMrsquos warning note ldquoNo medical messagerdquoIn addition it should be noted that no detailsof the dosage of kava or period of its adminis-tration were apparently recorded for this caseThis is clearly insufficient information onwhich to base a probable assessment
Case 16 This case concerned a 33-year-oldwoman with jaundice The woman wasrecorded as having taken an overdose of alco-hol measured at 60 g (Russman et al 2001) andthen analgesics including paracetamol fol-lowing this alcohol binge Despite the massiveintake of alcohol a liver biopsy indicated thata drug rather than an alcohol induced toxicgenesis However this case like that of Case 10above was discussed by Russman et al (2001)who demonstrated afterward that this patientwas shown to be CYP2D6 deficient which (asdiscussed below) seems to be a risk factor forthe hepatotoxicity that was ascribed to kavaWe submit that given these circumstances thiscase should be considered possible rather thanprobable
Case 18 This case concerned a 50-year-oldman who had necrosis leading to a liver trans-plant This patient took a product manufac-tured by acetone extraction at a dose deliver-ing 210ndash280 mg of kavalactones per day for 15months ldquomoderate alcoholrdquo (ldquomoderaterdquo is notdefined by BfArM) evening primrose(Oenothera biennis) and a yeast preparationThe dosage of kava was well above the Ger-man Commission E recommended dose ofkavalactones (Blumenthal 1998) It was alsorecorded that 500ndash1000 mg of paracetamol wastaken by this patient shortly before transplan-tation The combination of paracetamol and al-cohol plus the very high dose of kava extractedin acetone taken by this man casts seriousdoubts on the assessment of probable in thiscase
Case 28 (BAH) This case concerned a
KAVA WORK-IN-PROGRESS 243
woman age unknown with hepatitis This caseis hard to assess because neither the patientrsquosage nor diagnosis was given and the womanwas taking eleven medications including estra-diol valerate acetylcysteine losartan (which israrely be associated with hepatitis) and mepra-zole (which can be associated with liver diseasealthough this is rare) Omeprazole is metabo-lized by the polymorphic CYP2C19 which is absent in 3 of Caucasians (Flockhart et al2000) The woman was also taking echinacea(Echinacea purpurea) and five products that ap-peared to be for upper respiratory problems Itshould be noted that this patient was taking syn-thetic kavain not kava A comment from BfArMconcerning this case noted ldquorecurrence of the he-patic side-effectsrdquo which has evidently been in-terpreted by some authorities as being equiva-lent to a ldquopositive rechallengerdquo Whether or notthis was actually so was not clear from the datasupplied It appears (Schmidt and Nahrstedt2002) that Case 28 has been published as twocases with slightly different details This is con-fusing and considering that the woman was tak-ing 11 other medications together with a syn-thetic kava (which we submit is not equivalentto natural kava) and that no diagnosis of hercondition was supplied this calls the assessmentof probable in this case into question
(2) Cases associated with taking synthetic kavain
In this category there were 4 cases 1 2 19and 28
In each of these cases the patients concernedwere taking a product made from synthetickavain Although the outcome was hepatitis inall four cases kavain cannot be equated withthe naturally occurring form of kava whichcontains many other constituents that may playan important role in ensuring the safety of thisherb Therefore we submit that no inferenceshould be drawn from these cases Traditionalusage should not be taken as evidence for safeusage of synthetic products
(3) Patients who were taking oral contraceptivepills or hormone replacement therapy (HRT)together with drugs that can also be associatedwith liver damage
The cases in this category were 4 10 12 2021 and 28
Cholestatic jaundice associated with use ofestrogen-containing medications is extremelyrare (Lindberg 1992) but does occur In these6 cases the women were also taking drugs thatcan also be associated with jaundice
Case 4 This case involved a 39-year-oldwoman with jaundice She was on diazepam10 mg PRN for 6 months Some authoritiescalled this case possible Our assessment is thatthe case is unassessable
Case 10 This case involved a 39-year-oldwoman with necrotizing hepatitis For a de-tailed assessment see above
Case 12 This case involved a 37-year-oldwoman with hepatitis She was on 150 mg ofdiclofenac via intramuscular injection Hepato-toxic reactions associated with nonsteroidalanti-inflammatory drug use are extremely rareand concomitant exposure to other hepatotoxicdrugs is considered to be an important factor(Bareille et al 2001) This case of hepatitis isdifficult to interpret because it occurred inBrazil and because ldquoreexposure was said to benegative for all three drugsrdquo We regard thiscase as unassessable
Case 20 This case involved 50-year-oldwoman with necrosis who had a liver trans-plant She had a 20-year history of combinedoral contraceptive use but had changed monthsearlier to estradiol valerate (which was appar-ently taken alone) as HRT She had also startedglimepiride 8 months earlier This is used fortreating type II diabetes and is rarely associatedwith cholestatic jaundice and liver failure Weregard this case as unlikely
Case 21 This case involved a 22-year-oldwoman with necrosis who had a liver trans-plant This woman had changed from Valette(Jenapharm GmbH Jena Germany) (2 mg ofdienogest and 003 mg of ethinlestradiol) toPramino (180215250 mcg of norgestimateand mcg 25 of ethinylestradiol) She also tookrizatriptan if required for migraine reliefRizatriptan should be used with caution in he-patic impairment and avoided if a patient hassevere liver disease Some authorities considerthis case as being possible but our assessment
DENHAM ET AL244
is in view of the other medications taken isthat this case is unassessable
Case 28 This case involved a woman age un-known with hepatitis This case is discussed atlength above As noted above this patient wastaking synthetic kavain not kava
(4) Patients who were taking drugs that can beassociated with liver damage
There were ten cases in this category 1 6 914 15 17 19 23 2627 and 29
Case 1 This case involved a woman age 69with cholestatic hepatitis She was taking pen-toxifylline (which can be associated with intra-hepatic cholestasis) and a diuretic including thepotassium-sparing triamterene (which can beassociated with jaundice) As noted above thispatient was taking synthetic kavain not kavaWe consider this case unassessable
Case 6 This case involved a woman age 50with hepatitis She was taking frusemide(which can be associated with cholestatic jaun-dice) triamterene atenolol and a large dose ofterfenadine (300 mg) The recommended doseof terfenadine in the British National Formu-lary (March 2001) is 60ndash120 mg The Formularyrecommends avoiding this drug in patientswho have hepatic impairment and also says toldquoavoid concomitant administration of drugs li-able to produce electrolyte imbalance such asdiureticsrdquo (British National Formulary 2001)Despite this warning this woman was also tak-ing the diuretic frusemide The InterkantonalenKontrollstelle der Schweiz of Switzerland con-sidered this case of hepatitis to be caused byterfenadine And although some authoritiesregard this case as possible our assessment isthat this case is unlikely
Case 9 This case involved an 81-year-oldwoman who had liver failure and subsequentdeath She was taking hydrochlorothiazide(which can occasionally be associated with in-trahepatic cholestasis) However according toSchmidt and Nahrstedt (2002) there was evi-dence of chronic alcohol abuse and they re-ported that the autopsy showed chronic pan-creatitis that was characteristic of alcoholabuse The autopsy report (Schmidt and
Nahrstedt 2002) apparently said that thesymptoms must have occurred over a periodof at least 18 months The report conceded thatldquohepatic impairment by alcohol [was] not ex-cludedrdquo In these circumstances it seems en-tirely reasonable to claim that this case is un-related to kava use We regard this case asunlikely
Case 14 This case involved a 33-year-oldwoman with hepatitis Cisapride may havebeen taken (which can cause reversible changesthat show in liver-function tests) Cirrhosis ina woman of 33 is an unexplained finding andthe detail in this case is inadequate to elucidateit We consider this case to be unassessable
Case 15 This case involved a 46-year-oldwoman with jaundice She had been taking hy-drochlorothiazide (which can be associatedwith intrahepatic cholestasis) for 55 monthsplus 80 mg of valsartan and 80 mg ofpropanolol per day Some authorities regardthis case as possible but we consider it to beunassessable
Case 17 This case involved a 59-year-oldwoman with jaundice She had taken 100ndash200mg of celecoxib a cyclo-oxygenase-2 inhibitorper day According to the criteria for causalityassessment of adverse reactions some author-ities consider this case to be possible but our as-sessment is that it is unassessable
Case 19 This case involved a 21-year-oldwoman with hepatitis She was taking panto-prazole (which as with omeprazole can be as-sociated with liver disease) She was also takingparacetamol and metoclopramide and had over-dosed on kavain More detail is needed on othermedical conditions suffered by this patient in or-der to interpret this case It is suggested bySchmidt that this woman was using up to 10tablets per day of the product (the recom-mended dose is up to 6 tablets per day) and thatthere was apparently a discussion in her med-ical record file that she may also have used Ec-stasy (substance that has been associated with
KAVA WORK-IN-PROGRESS 245
Personal communication from M McGuffin to M McIn-tyre available as an online document at ehpaglobalnetcouk
fulminant hepatic failure) This case appears tobe unassessable
Case 23 This case involved a 35-year-oldwoman with jaundice According to the BfArM(see Appendix 2) this patient also took parac-etamol but no dosage or details were providedThis case and case 25 in the BfArM listing ap-pear to be the same case Both cases have beenlabeled as possible by some authorities butgiven the lack of information about the dosageof paracetamol and the apparent confusion re-garding cases 23 and 25 we submit that theonly logical assessment is unassessable
Case 2627 This case involved a woman whowas either 38 or 39 yearsrsquo old with hepatitis Itappears that the two cases have been duplicated(Schmidt and Nahrstedt 2002) The confusionwith this case is another example of inaccuratedata provided by the BfArM Information re-garding these cases (or case) depending onwhether the two reports concern the samewoman is unclear Penicillin can be associatedwith hypersensitivity and cholestatic jaundicebut the information given is inadequate to makeany meaningful assessment For this reason weclass this case as unassessable
Case 29 This case involved a 60-year-oldwoman who had a liver transplant This womanwas taking piretamide (which is a loop diuretic)Frusemide another loop diuretic can be associ-ated with cholestatic jaundice According to theBfArM chart (see Appendix 2) she was also tak-ing a sympathomimetic drug etilefrin Thedosage of kava varied but was up to 480ndash1200mg per day (Schmidt and Nahrstedt 2002)which is up to ten times the German Commis-sion E maximum recommended dose (Blumen-thal 1998) Although some authorities have re-garded this case as possible in view of themarked overdosing of kava and the concomitantmedication this case can hardly be said to be areflection on the proper therapeutic use of kava
(5) Cases in which drugs not associated withliver damage herbal medicines or dietarysupplements or kavain alone were taken
This category had eight cases 2 78 11 1322 24 and 25
For these cases detail was limited and theBfArM did not implicate any other drugs ormedications (although this may not be thecase)
All patients in this group apart from the pa-tient in Case 78 for whom no information wasgiven were reported to have made full recov-eries In some of these cases it is not clearwhether the patients were ill or whether thesecases merely recorded raised liver-function en-zymes
Case 2 This case involved a 35-year-old manwith cholestatic hepatitis Concomitant med-ication was ldquounknownrdquo Apart from Cases 18and 30 this is the only case for which it is pos-sible that no other concomitant medication wastaken but there is a marked lack of informationfor this case As noted above this patient wastaking synthetic kavain not kava We regardthis case as unassessable
Case 5 This case involved a woman who waseither 68 or 69 yearsrsquo old with cholestatic he-patitis She was also taking a St Johnrsquos wort(Hypericum perforatum) product which hasbeen associated with CYP3A4 A biopsyshowed ldquoimmunologic hypersensitivityrdquo Thiscase may be regarded as possible but in viewof the immunologic hypersensitivity it maywell have been an idiosyncratic event that wasnot necessarily associated with kava usage
Case 78 This case involved a woman or twowomen ages 72 andor 75 with cholestatic he-patitis These two cases appear to be actuallyone case The woman was taking twoherbalvitamin products one of which in-cluded 06 mg of kavalactones Given the con-fusion involved these ldquocasesrdquo must be re-garded as unassessable
Case 11 This case involved a 59-year-oldwoman who was taking hyoscine butylbro-mide as a suppository Schmidt and Nahrstedt(2002) commented that according to additionalinformation obtained from the BfArM it is un-certain as to whether this patient was taking akava product at all We regard this case asunassessable
DENHAM ET AL246
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
(1) Cases of most concern
This group includes five cases 10 13 16 18and 28 According to the assessments made by various government agencies these casescause the most concern and are often cited asbeing probable For this reason these cases aredealt with first As discussed below mostmdashifnot allmdashof these cases have associated factorsthat put this probable categorization into ques-tion
Case 10 This case described necrotizing hep-atitis in a 39-year old female patient with pos-itive reexposure (Strahl et al 1998) During thefirst period that the kava product was takenan oral contraceptive and paroxetine were con-comitant medications It appears that paroxe-tine was not the only antidepressant taken bythis patient who also occasionally took StJohnrsquos wort (Hypericum perforatum) The Exec-utive Summary issued by the Bundesverbandder Arzneimittel Hersteller eV (BAH) andBundesverband der Pharmazeutischen Indus-trie eV (BP) (see Appendix 3) stated ldquoA causalrelationship with kava cannot be excluded butthe patientrsquos history and a potential preexistingliver damage must be taken into account In ad-dition the kava preparation used was not iden-tified by the physicianrdquo
Moreover in this case taking paroxetine incombination with an oral contraceptive maywell have led to overburdening the liver a sit-uation that could have been exacerbated by tak-ing a kava preparation Schmidt and Nahrstedt(2002) suggested that this case may be associ-ated with an immunologic reaction After re-viewing all of the cases in detail Schmidt andNahrstedt (2002) concluded that this is the onlycase for which there was sufficient informationto make an association with kava appear prob-able and for which the dose of kava also con-formed to that recommended by the Com-mission E monograph (Blumenthal 2000)However as discussed below Russmann et al(2001) tested this patient for CYP2D6 and as inCase 16 found this patient to be CYP2D6 defi-cient which appears to have made her partic-ularly vulnerable to the cocktail of drugs shewas taking Given the complicating features ofthis case we submit that this case should beclassed as possible rather than probable
Case 13 This was a case of a 62-year-oldwoman with jaundice The BfArM table (seeAppendix 2) noted regarding concomitantmedication that there was ldquonone denotedrdquo butit was claimed that concomitant medication didexist but was ldquounknownrdquo The insufficiency ofdata provided for this case was highlighted byBfArMrsquos warning note ldquoNo medical messagerdquoIn addition it should be noted that no detailsof the dosage of kava or period of its adminis-tration were apparently recorded for this caseThis is clearly insufficient information onwhich to base a probable assessment
Case 16 This case concerned a 33-year-oldwoman with jaundice The woman wasrecorded as having taken an overdose of alco-hol measured at 60 g (Russman et al 2001) andthen analgesics including paracetamol fol-lowing this alcohol binge Despite the massiveintake of alcohol a liver biopsy indicated thata drug rather than an alcohol induced toxicgenesis However this case like that of Case 10above was discussed by Russman et al (2001)who demonstrated afterward that this patientwas shown to be CYP2D6 deficient which (asdiscussed below) seems to be a risk factor forthe hepatotoxicity that was ascribed to kavaWe submit that given these circumstances thiscase should be considered possible rather thanprobable
Case 18 This case concerned a 50-year-oldman who had necrosis leading to a liver trans-plant This patient took a product manufac-tured by acetone extraction at a dose deliver-ing 210ndash280 mg of kavalactones per day for 15months ldquomoderate alcoholrdquo (ldquomoderaterdquo is notdefined by BfArM) evening primrose(Oenothera biennis) and a yeast preparationThe dosage of kava was well above the Ger-man Commission E recommended dose ofkavalactones (Blumenthal 1998) It was alsorecorded that 500ndash1000 mg of paracetamol wastaken by this patient shortly before transplan-tation The combination of paracetamol and al-cohol plus the very high dose of kava extractedin acetone taken by this man casts seriousdoubts on the assessment of probable in thiscase
Case 28 (BAH) This case concerned a
KAVA WORK-IN-PROGRESS 243
woman age unknown with hepatitis This caseis hard to assess because neither the patientrsquosage nor diagnosis was given and the womanwas taking eleven medications including estra-diol valerate acetylcysteine losartan (which israrely be associated with hepatitis) and mepra-zole (which can be associated with liver diseasealthough this is rare) Omeprazole is metabo-lized by the polymorphic CYP2C19 which is absent in 3 of Caucasians (Flockhart et al2000) The woman was also taking echinacea(Echinacea purpurea) and five products that ap-peared to be for upper respiratory problems Itshould be noted that this patient was taking syn-thetic kavain not kava A comment from BfArMconcerning this case noted ldquorecurrence of the he-patic side-effectsrdquo which has evidently been in-terpreted by some authorities as being equiva-lent to a ldquopositive rechallengerdquo Whether or notthis was actually so was not clear from the datasupplied It appears (Schmidt and Nahrstedt2002) that Case 28 has been published as twocases with slightly different details This is con-fusing and considering that the woman was tak-ing 11 other medications together with a syn-thetic kava (which we submit is not equivalentto natural kava) and that no diagnosis of hercondition was supplied this calls the assessmentof probable in this case into question
(2) Cases associated with taking synthetic kavain
In this category there were 4 cases 1 2 19and 28
In each of these cases the patients concernedwere taking a product made from synthetickavain Although the outcome was hepatitis inall four cases kavain cannot be equated withthe naturally occurring form of kava whichcontains many other constituents that may playan important role in ensuring the safety of thisherb Therefore we submit that no inferenceshould be drawn from these cases Traditionalusage should not be taken as evidence for safeusage of synthetic products
(3) Patients who were taking oral contraceptivepills or hormone replacement therapy (HRT)together with drugs that can also be associatedwith liver damage
The cases in this category were 4 10 12 2021 and 28
Cholestatic jaundice associated with use ofestrogen-containing medications is extremelyrare (Lindberg 1992) but does occur In these6 cases the women were also taking drugs thatcan also be associated with jaundice
Case 4 This case involved a 39-year-oldwoman with jaundice She was on diazepam10 mg PRN for 6 months Some authoritiescalled this case possible Our assessment is thatthe case is unassessable
Case 10 This case involved a 39-year-oldwoman with necrotizing hepatitis For a de-tailed assessment see above
Case 12 This case involved a 37-year-oldwoman with hepatitis She was on 150 mg ofdiclofenac via intramuscular injection Hepato-toxic reactions associated with nonsteroidalanti-inflammatory drug use are extremely rareand concomitant exposure to other hepatotoxicdrugs is considered to be an important factor(Bareille et al 2001) This case of hepatitis isdifficult to interpret because it occurred inBrazil and because ldquoreexposure was said to benegative for all three drugsrdquo We regard thiscase as unassessable
Case 20 This case involved 50-year-oldwoman with necrosis who had a liver trans-plant She had a 20-year history of combinedoral contraceptive use but had changed monthsearlier to estradiol valerate (which was appar-ently taken alone) as HRT She had also startedglimepiride 8 months earlier This is used fortreating type II diabetes and is rarely associatedwith cholestatic jaundice and liver failure Weregard this case as unlikely
Case 21 This case involved a 22-year-oldwoman with necrosis who had a liver trans-plant This woman had changed from Valette(Jenapharm GmbH Jena Germany) (2 mg ofdienogest and 003 mg of ethinlestradiol) toPramino (180215250 mcg of norgestimateand mcg 25 of ethinylestradiol) She also tookrizatriptan if required for migraine reliefRizatriptan should be used with caution in he-patic impairment and avoided if a patient hassevere liver disease Some authorities considerthis case as being possible but our assessment
DENHAM ET AL244
is in view of the other medications taken isthat this case is unassessable
Case 28 This case involved a woman age un-known with hepatitis This case is discussed atlength above As noted above this patient wastaking synthetic kavain not kava
(4) Patients who were taking drugs that can beassociated with liver damage
There were ten cases in this category 1 6 914 15 17 19 23 2627 and 29
Case 1 This case involved a woman age 69with cholestatic hepatitis She was taking pen-toxifylline (which can be associated with intra-hepatic cholestasis) and a diuretic including thepotassium-sparing triamterene (which can beassociated with jaundice) As noted above thispatient was taking synthetic kavain not kavaWe consider this case unassessable
Case 6 This case involved a woman age 50with hepatitis She was taking frusemide(which can be associated with cholestatic jaun-dice) triamterene atenolol and a large dose ofterfenadine (300 mg) The recommended doseof terfenadine in the British National Formu-lary (March 2001) is 60ndash120 mg The Formularyrecommends avoiding this drug in patientswho have hepatic impairment and also says toldquoavoid concomitant administration of drugs li-able to produce electrolyte imbalance such asdiureticsrdquo (British National Formulary 2001)Despite this warning this woman was also tak-ing the diuretic frusemide The InterkantonalenKontrollstelle der Schweiz of Switzerland con-sidered this case of hepatitis to be caused byterfenadine And although some authoritiesregard this case as possible our assessment isthat this case is unlikely
Case 9 This case involved an 81-year-oldwoman who had liver failure and subsequentdeath She was taking hydrochlorothiazide(which can occasionally be associated with in-trahepatic cholestasis) However according toSchmidt and Nahrstedt (2002) there was evi-dence of chronic alcohol abuse and they re-ported that the autopsy showed chronic pan-creatitis that was characteristic of alcoholabuse The autopsy report (Schmidt and
Nahrstedt 2002) apparently said that thesymptoms must have occurred over a periodof at least 18 months The report conceded thatldquohepatic impairment by alcohol [was] not ex-cludedrdquo In these circumstances it seems en-tirely reasonable to claim that this case is un-related to kava use We regard this case asunlikely
Case 14 This case involved a 33-year-oldwoman with hepatitis Cisapride may havebeen taken (which can cause reversible changesthat show in liver-function tests) Cirrhosis ina woman of 33 is an unexplained finding andthe detail in this case is inadequate to elucidateit We consider this case to be unassessable
Case 15 This case involved a 46-year-oldwoman with jaundice She had been taking hy-drochlorothiazide (which can be associatedwith intrahepatic cholestasis) for 55 monthsplus 80 mg of valsartan and 80 mg ofpropanolol per day Some authorities regardthis case as possible but we consider it to beunassessable
Case 17 This case involved a 59-year-oldwoman with jaundice She had taken 100ndash200mg of celecoxib a cyclo-oxygenase-2 inhibitorper day According to the criteria for causalityassessment of adverse reactions some author-ities consider this case to be possible but our as-sessment is that it is unassessable
Case 19 This case involved a 21-year-oldwoman with hepatitis She was taking panto-prazole (which as with omeprazole can be as-sociated with liver disease) She was also takingparacetamol and metoclopramide and had over-dosed on kavain More detail is needed on othermedical conditions suffered by this patient in or-der to interpret this case It is suggested bySchmidt that this woman was using up to 10tablets per day of the product (the recom-mended dose is up to 6 tablets per day) and thatthere was apparently a discussion in her med-ical record file that she may also have used Ec-stasy (substance that has been associated with
KAVA WORK-IN-PROGRESS 245
Personal communication from M McGuffin to M McIn-tyre available as an online document at ehpaglobalnetcouk
fulminant hepatic failure) This case appears tobe unassessable
Case 23 This case involved a 35-year-oldwoman with jaundice According to the BfArM(see Appendix 2) this patient also took parac-etamol but no dosage or details were providedThis case and case 25 in the BfArM listing ap-pear to be the same case Both cases have beenlabeled as possible by some authorities butgiven the lack of information about the dosageof paracetamol and the apparent confusion re-garding cases 23 and 25 we submit that theonly logical assessment is unassessable
Case 2627 This case involved a woman whowas either 38 or 39 yearsrsquo old with hepatitis Itappears that the two cases have been duplicated(Schmidt and Nahrstedt 2002) The confusionwith this case is another example of inaccuratedata provided by the BfArM Information re-garding these cases (or case) depending onwhether the two reports concern the samewoman is unclear Penicillin can be associatedwith hypersensitivity and cholestatic jaundicebut the information given is inadequate to makeany meaningful assessment For this reason weclass this case as unassessable
Case 29 This case involved a 60-year-oldwoman who had a liver transplant This womanwas taking piretamide (which is a loop diuretic)Frusemide another loop diuretic can be associ-ated with cholestatic jaundice According to theBfArM chart (see Appendix 2) she was also tak-ing a sympathomimetic drug etilefrin Thedosage of kava varied but was up to 480ndash1200mg per day (Schmidt and Nahrstedt 2002)which is up to ten times the German Commis-sion E maximum recommended dose (Blumen-thal 1998) Although some authorities have re-garded this case as possible in view of themarked overdosing of kava and the concomitantmedication this case can hardly be said to be areflection on the proper therapeutic use of kava
(5) Cases in which drugs not associated withliver damage herbal medicines or dietarysupplements or kavain alone were taken
This category had eight cases 2 78 11 1322 24 and 25
For these cases detail was limited and theBfArM did not implicate any other drugs ormedications (although this may not be thecase)
All patients in this group apart from the pa-tient in Case 78 for whom no information wasgiven were reported to have made full recov-eries In some of these cases it is not clearwhether the patients were ill or whether thesecases merely recorded raised liver-function en-zymes
Case 2 This case involved a 35-year-old manwith cholestatic hepatitis Concomitant med-ication was ldquounknownrdquo Apart from Cases 18and 30 this is the only case for which it is pos-sible that no other concomitant medication wastaken but there is a marked lack of informationfor this case As noted above this patient wastaking synthetic kavain not kava We regardthis case as unassessable
Case 5 This case involved a woman who waseither 68 or 69 yearsrsquo old with cholestatic he-patitis She was also taking a St Johnrsquos wort(Hypericum perforatum) product which hasbeen associated with CYP3A4 A biopsyshowed ldquoimmunologic hypersensitivityrdquo Thiscase may be regarded as possible but in viewof the immunologic hypersensitivity it maywell have been an idiosyncratic event that wasnot necessarily associated with kava usage
Case 78 This case involved a woman or twowomen ages 72 andor 75 with cholestatic he-patitis These two cases appear to be actuallyone case The woman was taking twoherbalvitamin products one of which in-cluded 06 mg of kavalactones Given the con-fusion involved these ldquocasesrdquo must be re-garded as unassessable
Case 11 This case involved a 59-year-oldwoman who was taking hyoscine butylbro-mide as a suppository Schmidt and Nahrstedt(2002) commented that according to additionalinformation obtained from the BfArM it is un-certain as to whether this patient was taking akava product at all We regard this case asunassessable
DENHAM ET AL246
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
woman age unknown with hepatitis This caseis hard to assess because neither the patientrsquosage nor diagnosis was given and the womanwas taking eleven medications including estra-diol valerate acetylcysteine losartan (which israrely be associated with hepatitis) and mepra-zole (which can be associated with liver diseasealthough this is rare) Omeprazole is metabo-lized by the polymorphic CYP2C19 which is absent in 3 of Caucasians (Flockhart et al2000) The woman was also taking echinacea(Echinacea purpurea) and five products that ap-peared to be for upper respiratory problems Itshould be noted that this patient was taking syn-thetic kavain not kava A comment from BfArMconcerning this case noted ldquorecurrence of the he-patic side-effectsrdquo which has evidently been in-terpreted by some authorities as being equiva-lent to a ldquopositive rechallengerdquo Whether or notthis was actually so was not clear from the datasupplied It appears (Schmidt and Nahrstedt2002) that Case 28 has been published as twocases with slightly different details This is con-fusing and considering that the woman was tak-ing 11 other medications together with a syn-thetic kava (which we submit is not equivalentto natural kava) and that no diagnosis of hercondition was supplied this calls the assessmentof probable in this case into question
(2) Cases associated with taking synthetic kavain
In this category there were 4 cases 1 2 19and 28
In each of these cases the patients concernedwere taking a product made from synthetickavain Although the outcome was hepatitis inall four cases kavain cannot be equated withthe naturally occurring form of kava whichcontains many other constituents that may playan important role in ensuring the safety of thisherb Therefore we submit that no inferenceshould be drawn from these cases Traditionalusage should not be taken as evidence for safeusage of synthetic products
(3) Patients who were taking oral contraceptivepills or hormone replacement therapy (HRT)together with drugs that can also be associatedwith liver damage
The cases in this category were 4 10 12 2021 and 28
Cholestatic jaundice associated with use ofestrogen-containing medications is extremelyrare (Lindberg 1992) but does occur In these6 cases the women were also taking drugs thatcan also be associated with jaundice
Case 4 This case involved a 39-year-oldwoman with jaundice She was on diazepam10 mg PRN for 6 months Some authoritiescalled this case possible Our assessment is thatthe case is unassessable
Case 10 This case involved a 39-year-oldwoman with necrotizing hepatitis For a de-tailed assessment see above
Case 12 This case involved a 37-year-oldwoman with hepatitis She was on 150 mg ofdiclofenac via intramuscular injection Hepato-toxic reactions associated with nonsteroidalanti-inflammatory drug use are extremely rareand concomitant exposure to other hepatotoxicdrugs is considered to be an important factor(Bareille et al 2001) This case of hepatitis isdifficult to interpret because it occurred inBrazil and because ldquoreexposure was said to benegative for all three drugsrdquo We regard thiscase as unassessable
Case 20 This case involved 50-year-oldwoman with necrosis who had a liver trans-plant She had a 20-year history of combinedoral contraceptive use but had changed monthsearlier to estradiol valerate (which was appar-ently taken alone) as HRT She had also startedglimepiride 8 months earlier This is used fortreating type II diabetes and is rarely associatedwith cholestatic jaundice and liver failure Weregard this case as unlikely
Case 21 This case involved a 22-year-oldwoman with necrosis who had a liver trans-plant This woman had changed from Valette(Jenapharm GmbH Jena Germany) (2 mg ofdienogest and 003 mg of ethinlestradiol) toPramino (180215250 mcg of norgestimateand mcg 25 of ethinylestradiol) She also tookrizatriptan if required for migraine reliefRizatriptan should be used with caution in he-patic impairment and avoided if a patient hassevere liver disease Some authorities considerthis case as being possible but our assessment
DENHAM ET AL244
is in view of the other medications taken isthat this case is unassessable
Case 28 This case involved a woman age un-known with hepatitis This case is discussed atlength above As noted above this patient wastaking synthetic kavain not kava
(4) Patients who were taking drugs that can beassociated with liver damage
There were ten cases in this category 1 6 914 15 17 19 23 2627 and 29
Case 1 This case involved a woman age 69with cholestatic hepatitis She was taking pen-toxifylline (which can be associated with intra-hepatic cholestasis) and a diuretic including thepotassium-sparing triamterene (which can beassociated with jaundice) As noted above thispatient was taking synthetic kavain not kavaWe consider this case unassessable
Case 6 This case involved a woman age 50with hepatitis She was taking frusemide(which can be associated with cholestatic jaun-dice) triamterene atenolol and a large dose ofterfenadine (300 mg) The recommended doseof terfenadine in the British National Formu-lary (March 2001) is 60ndash120 mg The Formularyrecommends avoiding this drug in patientswho have hepatic impairment and also says toldquoavoid concomitant administration of drugs li-able to produce electrolyte imbalance such asdiureticsrdquo (British National Formulary 2001)Despite this warning this woman was also tak-ing the diuretic frusemide The InterkantonalenKontrollstelle der Schweiz of Switzerland con-sidered this case of hepatitis to be caused byterfenadine And although some authoritiesregard this case as possible our assessment isthat this case is unlikely
Case 9 This case involved an 81-year-oldwoman who had liver failure and subsequentdeath She was taking hydrochlorothiazide(which can occasionally be associated with in-trahepatic cholestasis) However according toSchmidt and Nahrstedt (2002) there was evi-dence of chronic alcohol abuse and they re-ported that the autopsy showed chronic pan-creatitis that was characteristic of alcoholabuse The autopsy report (Schmidt and
Nahrstedt 2002) apparently said that thesymptoms must have occurred over a periodof at least 18 months The report conceded thatldquohepatic impairment by alcohol [was] not ex-cludedrdquo In these circumstances it seems en-tirely reasonable to claim that this case is un-related to kava use We regard this case asunlikely
Case 14 This case involved a 33-year-oldwoman with hepatitis Cisapride may havebeen taken (which can cause reversible changesthat show in liver-function tests) Cirrhosis ina woman of 33 is an unexplained finding andthe detail in this case is inadequate to elucidateit We consider this case to be unassessable
Case 15 This case involved a 46-year-oldwoman with jaundice She had been taking hy-drochlorothiazide (which can be associatedwith intrahepatic cholestasis) for 55 monthsplus 80 mg of valsartan and 80 mg ofpropanolol per day Some authorities regardthis case as possible but we consider it to beunassessable
Case 17 This case involved a 59-year-oldwoman with jaundice She had taken 100ndash200mg of celecoxib a cyclo-oxygenase-2 inhibitorper day According to the criteria for causalityassessment of adverse reactions some author-ities consider this case to be possible but our as-sessment is that it is unassessable
Case 19 This case involved a 21-year-oldwoman with hepatitis She was taking panto-prazole (which as with omeprazole can be as-sociated with liver disease) She was also takingparacetamol and metoclopramide and had over-dosed on kavain More detail is needed on othermedical conditions suffered by this patient in or-der to interpret this case It is suggested bySchmidt that this woman was using up to 10tablets per day of the product (the recom-mended dose is up to 6 tablets per day) and thatthere was apparently a discussion in her med-ical record file that she may also have used Ec-stasy (substance that has been associated with
KAVA WORK-IN-PROGRESS 245
Personal communication from M McGuffin to M McIn-tyre available as an online document at ehpaglobalnetcouk
fulminant hepatic failure) This case appears tobe unassessable
Case 23 This case involved a 35-year-oldwoman with jaundice According to the BfArM(see Appendix 2) this patient also took parac-etamol but no dosage or details were providedThis case and case 25 in the BfArM listing ap-pear to be the same case Both cases have beenlabeled as possible by some authorities butgiven the lack of information about the dosageof paracetamol and the apparent confusion re-garding cases 23 and 25 we submit that theonly logical assessment is unassessable
Case 2627 This case involved a woman whowas either 38 or 39 yearsrsquo old with hepatitis Itappears that the two cases have been duplicated(Schmidt and Nahrstedt 2002) The confusionwith this case is another example of inaccuratedata provided by the BfArM Information re-garding these cases (or case) depending onwhether the two reports concern the samewoman is unclear Penicillin can be associatedwith hypersensitivity and cholestatic jaundicebut the information given is inadequate to makeany meaningful assessment For this reason weclass this case as unassessable
Case 29 This case involved a 60-year-oldwoman who had a liver transplant This womanwas taking piretamide (which is a loop diuretic)Frusemide another loop diuretic can be associ-ated with cholestatic jaundice According to theBfArM chart (see Appendix 2) she was also tak-ing a sympathomimetic drug etilefrin Thedosage of kava varied but was up to 480ndash1200mg per day (Schmidt and Nahrstedt 2002)which is up to ten times the German Commis-sion E maximum recommended dose (Blumen-thal 1998) Although some authorities have re-garded this case as possible in view of themarked overdosing of kava and the concomitantmedication this case can hardly be said to be areflection on the proper therapeutic use of kava
(5) Cases in which drugs not associated withliver damage herbal medicines or dietarysupplements or kavain alone were taken
This category had eight cases 2 78 11 1322 24 and 25
For these cases detail was limited and theBfArM did not implicate any other drugs ormedications (although this may not be thecase)
All patients in this group apart from the pa-tient in Case 78 for whom no information wasgiven were reported to have made full recov-eries In some of these cases it is not clearwhether the patients were ill or whether thesecases merely recorded raised liver-function en-zymes
Case 2 This case involved a 35-year-old manwith cholestatic hepatitis Concomitant med-ication was ldquounknownrdquo Apart from Cases 18and 30 this is the only case for which it is pos-sible that no other concomitant medication wastaken but there is a marked lack of informationfor this case As noted above this patient wastaking synthetic kavain not kava We regardthis case as unassessable
Case 5 This case involved a woman who waseither 68 or 69 yearsrsquo old with cholestatic he-patitis She was also taking a St Johnrsquos wort(Hypericum perforatum) product which hasbeen associated with CYP3A4 A biopsyshowed ldquoimmunologic hypersensitivityrdquo Thiscase may be regarded as possible but in viewof the immunologic hypersensitivity it maywell have been an idiosyncratic event that wasnot necessarily associated with kava usage
Case 78 This case involved a woman or twowomen ages 72 andor 75 with cholestatic he-patitis These two cases appear to be actuallyone case The woman was taking twoherbalvitamin products one of which in-cluded 06 mg of kavalactones Given the con-fusion involved these ldquocasesrdquo must be re-garded as unassessable
Case 11 This case involved a 59-year-oldwoman who was taking hyoscine butylbro-mide as a suppository Schmidt and Nahrstedt(2002) commented that according to additionalinformation obtained from the BfArM it is un-certain as to whether this patient was taking akava product at all We regard this case asunassessable
DENHAM ET AL246
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
is in view of the other medications taken isthat this case is unassessable
Case 28 This case involved a woman age un-known with hepatitis This case is discussed atlength above As noted above this patient wastaking synthetic kavain not kava
(4) Patients who were taking drugs that can beassociated with liver damage
There were ten cases in this category 1 6 914 15 17 19 23 2627 and 29
Case 1 This case involved a woman age 69with cholestatic hepatitis She was taking pen-toxifylline (which can be associated with intra-hepatic cholestasis) and a diuretic including thepotassium-sparing triamterene (which can beassociated with jaundice) As noted above thispatient was taking synthetic kavain not kavaWe consider this case unassessable
Case 6 This case involved a woman age 50with hepatitis She was taking frusemide(which can be associated with cholestatic jaun-dice) triamterene atenolol and a large dose ofterfenadine (300 mg) The recommended doseof terfenadine in the British National Formu-lary (March 2001) is 60ndash120 mg The Formularyrecommends avoiding this drug in patientswho have hepatic impairment and also says toldquoavoid concomitant administration of drugs li-able to produce electrolyte imbalance such asdiureticsrdquo (British National Formulary 2001)Despite this warning this woman was also tak-ing the diuretic frusemide The InterkantonalenKontrollstelle der Schweiz of Switzerland con-sidered this case of hepatitis to be caused byterfenadine And although some authoritiesregard this case as possible our assessment isthat this case is unlikely
Case 9 This case involved an 81-year-oldwoman who had liver failure and subsequentdeath She was taking hydrochlorothiazide(which can occasionally be associated with in-trahepatic cholestasis) However according toSchmidt and Nahrstedt (2002) there was evi-dence of chronic alcohol abuse and they re-ported that the autopsy showed chronic pan-creatitis that was characteristic of alcoholabuse The autopsy report (Schmidt and
Nahrstedt 2002) apparently said that thesymptoms must have occurred over a periodof at least 18 months The report conceded thatldquohepatic impairment by alcohol [was] not ex-cludedrdquo In these circumstances it seems en-tirely reasonable to claim that this case is un-related to kava use We regard this case asunlikely
Case 14 This case involved a 33-year-oldwoman with hepatitis Cisapride may havebeen taken (which can cause reversible changesthat show in liver-function tests) Cirrhosis ina woman of 33 is an unexplained finding andthe detail in this case is inadequate to elucidateit We consider this case to be unassessable
Case 15 This case involved a 46-year-oldwoman with jaundice She had been taking hy-drochlorothiazide (which can be associatedwith intrahepatic cholestasis) for 55 monthsplus 80 mg of valsartan and 80 mg ofpropanolol per day Some authorities regardthis case as possible but we consider it to beunassessable
Case 17 This case involved a 59-year-oldwoman with jaundice She had taken 100ndash200mg of celecoxib a cyclo-oxygenase-2 inhibitorper day According to the criteria for causalityassessment of adverse reactions some author-ities consider this case to be possible but our as-sessment is that it is unassessable
Case 19 This case involved a 21-year-oldwoman with hepatitis She was taking panto-prazole (which as with omeprazole can be as-sociated with liver disease) She was also takingparacetamol and metoclopramide and had over-dosed on kavain More detail is needed on othermedical conditions suffered by this patient in or-der to interpret this case It is suggested bySchmidt that this woman was using up to 10tablets per day of the product (the recom-mended dose is up to 6 tablets per day) and thatthere was apparently a discussion in her med-ical record file that she may also have used Ec-stasy (substance that has been associated with
KAVA WORK-IN-PROGRESS 245
Personal communication from M McGuffin to M McIn-tyre available as an online document at ehpaglobalnetcouk
fulminant hepatic failure) This case appears tobe unassessable
Case 23 This case involved a 35-year-oldwoman with jaundice According to the BfArM(see Appendix 2) this patient also took parac-etamol but no dosage or details were providedThis case and case 25 in the BfArM listing ap-pear to be the same case Both cases have beenlabeled as possible by some authorities butgiven the lack of information about the dosageof paracetamol and the apparent confusion re-garding cases 23 and 25 we submit that theonly logical assessment is unassessable
Case 2627 This case involved a woman whowas either 38 or 39 yearsrsquo old with hepatitis Itappears that the two cases have been duplicated(Schmidt and Nahrstedt 2002) The confusionwith this case is another example of inaccuratedata provided by the BfArM Information re-garding these cases (or case) depending onwhether the two reports concern the samewoman is unclear Penicillin can be associatedwith hypersensitivity and cholestatic jaundicebut the information given is inadequate to makeany meaningful assessment For this reason weclass this case as unassessable
Case 29 This case involved a 60-year-oldwoman who had a liver transplant This womanwas taking piretamide (which is a loop diuretic)Frusemide another loop diuretic can be associ-ated with cholestatic jaundice According to theBfArM chart (see Appendix 2) she was also tak-ing a sympathomimetic drug etilefrin Thedosage of kava varied but was up to 480ndash1200mg per day (Schmidt and Nahrstedt 2002)which is up to ten times the German Commis-sion E maximum recommended dose (Blumen-thal 1998) Although some authorities have re-garded this case as possible in view of themarked overdosing of kava and the concomitantmedication this case can hardly be said to be areflection on the proper therapeutic use of kava
(5) Cases in which drugs not associated withliver damage herbal medicines or dietarysupplements or kavain alone were taken
This category had eight cases 2 78 11 1322 24 and 25
For these cases detail was limited and theBfArM did not implicate any other drugs ormedications (although this may not be thecase)
All patients in this group apart from the pa-tient in Case 78 for whom no information wasgiven were reported to have made full recov-eries In some of these cases it is not clearwhether the patients were ill or whether thesecases merely recorded raised liver-function en-zymes
Case 2 This case involved a 35-year-old manwith cholestatic hepatitis Concomitant med-ication was ldquounknownrdquo Apart from Cases 18and 30 this is the only case for which it is pos-sible that no other concomitant medication wastaken but there is a marked lack of informationfor this case As noted above this patient wastaking synthetic kavain not kava We regardthis case as unassessable
Case 5 This case involved a woman who waseither 68 or 69 yearsrsquo old with cholestatic he-patitis She was also taking a St Johnrsquos wort(Hypericum perforatum) product which hasbeen associated with CYP3A4 A biopsyshowed ldquoimmunologic hypersensitivityrdquo Thiscase may be regarded as possible but in viewof the immunologic hypersensitivity it maywell have been an idiosyncratic event that wasnot necessarily associated with kava usage
Case 78 This case involved a woman or twowomen ages 72 andor 75 with cholestatic he-patitis These two cases appear to be actuallyone case The woman was taking twoherbalvitamin products one of which in-cluded 06 mg of kavalactones Given the con-fusion involved these ldquocasesrdquo must be re-garded as unassessable
Case 11 This case involved a 59-year-oldwoman who was taking hyoscine butylbro-mide as a suppository Schmidt and Nahrstedt(2002) commented that according to additionalinformation obtained from the BfArM it is un-certain as to whether this patient was taking akava product at all We regard this case asunassessable
DENHAM ET AL246
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
fulminant hepatic failure) This case appears tobe unassessable
Case 23 This case involved a 35-year-oldwoman with jaundice According to the BfArM(see Appendix 2) this patient also took parac-etamol but no dosage or details were providedThis case and case 25 in the BfArM listing ap-pear to be the same case Both cases have beenlabeled as possible by some authorities butgiven the lack of information about the dosageof paracetamol and the apparent confusion re-garding cases 23 and 25 we submit that theonly logical assessment is unassessable
Case 2627 This case involved a woman whowas either 38 or 39 yearsrsquo old with hepatitis Itappears that the two cases have been duplicated(Schmidt and Nahrstedt 2002) The confusionwith this case is another example of inaccuratedata provided by the BfArM Information re-garding these cases (or case) depending onwhether the two reports concern the samewoman is unclear Penicillin can be associatedwith hypersensitivity and cholestatic jaundicebut the information given is inadequate to makeany meaningful assessment For this reason weclass this case as unassessable
Case 29 This case involved a 60-year-oldwoman who had a liver transplant This womanwas taking piretamide (which is a loop diuretic)Frusemide another loop diuretic can be associ-ated with cholestatic jaundice According to theBfArM chart (see Appendix 2) she was also tak-ing a sympathomimetic drug etilefrin Thedosage of kava varied but was up to 480ndash1200mg per day (Schmidt and Nahrstedt 2002)which is up to ten times the German Commis-sion E maximum recommended dose (Blumen-thal 1998) Although some authorities have re-garded this case as possible in view of themarked overdosing of kava and the concomitantmedication this case can hardly be said to be areflection on the proper therapeutic use of kava
(5) Cases in which drugs not associated withliver damage herbal medicines or dietarysupplements or kavain alone were taken
This category had eight cases 2 78 11 1322 24 and 25
For these cases detail was limited and theBfArM did not implicate any other drugs ormedications (although this may not be thecase)
All patients in this group apart from the pa-tient in Case 78 for whom no information wasgiven were reported to have made full recov-eries In some of these cases it is not clearwhether the patients were ill or whether thesecases merely recorded raised liver-function en-zymes
Case 2 This case involved a 35-year-old manwith cholestatic hepatitis Concomitant med-ication was ldquounknownrdquo Apart from Cases 18and 30 this is the only case for which it is pos-sible that no other concomitant medication wastaken but there is a marked lack of informationfor this case As noted above this patient wastaking synthetic kavain not kava We regardthis case as unassessable
Case 5 This case involved a woman who waseither 68 or 69 yearsrsquo old with cholestatic he-patitis She was also taking a St Johnrsquos wort(Hypericum perforatum) product which hasbeen associated with CYP3A4 A biopsyshowed ldquoimmunologic hypersensitivityrdquo Thiscase may be regarded as possible but in viewof the immunologic hypersensitivity it maywell have been an idiosyncratic event that wasnot necessarily associated with kava usage
Case 78 This case involved a woman or twowomen ages 72 andor 75 with cholestatic he-patitis These two cases appear to be actuallyone case The woman was taking twoherbalvitamin products one of which in-cluded 06 mg of kavalactones Given the con-fusion involved these ldquocasesrdquo must be re-garded as unassessable
Case 11 This case involved a 59-year-oldwoman who was taking hyoscine butylbro-mide as a suppository Schmidt and Nahrstedt(2002) commented that according to additionalinformation obtained from the BfArM it is un-certain as to whether this patient was taking akava product at all We regard this case asunassessable
DENHAM ET AL246
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
Case 13 This case involved a 62-year-oldwoman with jaundice See above for the dis-cussion of this case It does appear that therewas concomitant medication but no details ofthis or of the kava dosage are available Thismakes interpretation impossible consequentlywe regard this case as unassessable
Case 22 This case involved a 34-year-oldwoman with hepatitis She was taking L-thy-roxine No information is available on her vi-ral serology differential diagnosis or alcoholintake We regard this case as unassessable
Case 24 This case involved a 47-year-oldwoman who had raised liver-function asshown on a test She had a high intake of fish-oil The report stated that this patientrsquos liver en-zymes returned to normal when she stoppedtaking fish oils but again the detail is insuffi-cient However this case appears to supportthe safe use of kava because report stated thatthe patient was ldquorestored to health after dis-continuation of the concomitant medicationand continuation of the (kava) medicationrdquo Weconsider this case to be unlikely
Case 25 This case involved a 34-year-oldwoman with hepatitis According to the infor-mation provided by the BfArM this womanwas just taking Hypericum perforatum concomi-tantly There is confusion about whether this isthe same case as Case 23 and that as recordedby BfArM (see Appendix 2) paracetamol wasindeed a concomitant medicine This case mustbe classed as unlikely
(6) Cases associated with an overdose of alcohol
This group included two cases 16 and 9
Case 16 This case involved a 33-year-oldwoman with jaundice This case is discussed atlength above because some authorities regardthis case as being probable The woman took anoverdose of alcohol (recorded as 60 g) Thiscase was described in detail by Russman et al(2001) because the woman was deficient in CYP2D6 which as previously noted may havemade her vulnerable to the mixture of kava al-cohol and paracetamol (which were taken for
hangover symptoms) In these circumstancesas stated above this case is unlikely to be prob-able We believe it to be possible
Case 9 This case is discussed in subsection 4above
(7) Cases not associated with other drug usage
This group included two cases 18 and 30These final two cases involved men both of
whom required liver transplants and both ofwhom appeared not to have been taking othermedications For these two cases more detailson the medical histories is required for properassessment
Case 18 This case involved a 50-year-old manwith liver necrosis and who had a liver trans-plant This case is discussed in some detailabove The man took an 210ndash280 mg of an ace-tone preparation per day for 15 months Healso had a ldquomoderate alcoholrdquo intake and tooka yeast preparation This is above the recom-mended dose of kavalactones He may alsohave taken paracetamol (see above) This caseis unassessable
Case 30 This case involved a 32-year-old manwith necrosis of the liver and who had a livertransplant He took a product containing 240mg of kavalactones per day for 3 months andoccasionally a valerian (Valeriana officinalis)product at night This too was above the rec-ommended dose of kavalactones This case can-not be evaluated fully because of lack of de-tailed documentation regarding the manrsquosmedical history or the presenting disease andso must be categorized as unassessable
CYTOCHROME p450 METABOLISM OF XENOBIOTICS AND CYP2D6 DEFICIENCY
In most of these cases the patients were alsotaking drugs concomitantly Assuming that themedications were responsible for the adverseevents and not some other factors such as otherdisease or excessive use of alcohol it is possi-ble that the hepatotoxicity was caused by the
KAVA WORK-IN-PROGRESS 247
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
conventional drugs by the kava by both thedrugs and the kava or mainly by the drugs withthe kava as a cofactor However in assessingthese cases one should take into account theapparent increased risk of adverse effects on theliver where kavalactone concentration is en-hanced in a product In all cases cited by theBfArM the affected patients appear to havebeen taking concentrated standardized prod-ucts which in no way relates to the tradi-tional water-based or low-alcohol extracts thathave not been associated with comparable ad-verse events In any case upon analysis of allrelevant factors the number of cases cited bythe BfArM that can actually be attributed tokava is so low that the only logical conclusionthat can be drawn is that kava has a low levelof incidence of adverse events InterestinglySchmidt and Nahrstedt (2002) came to muchthe same conclusion stating that the relativeincidence of adverse events is a fraction of thatof others connected with anxiolytics such asbenzodiazepines
Interindividual variability in cytochrome-p450metabolism of xenobiotics
Kava may be regarded as a possible cofactorin some of these cases but variable individualresponses (interindividual variability) to drugsor herbs should also be taken into account inthese cases Interindividual variability in drugresponse is now increasingly recognized as amajor cause of adverse drug reactions Muchof this variability is now ascribed to genetic dif-ferences in drug absorption disposition me-tabolism or excretion The variability that hasbeen most investigated and that is consideredto be of most significance is genetic polymor-phism in drug metabolizing enzymes in thehepatocyte This is considered to be an adap-tive response to environmental challenge (Wolfand Smith 1999) so it is not in itself surprisingthat individuals vary and failure to metabolizexenobiotics (ldquoforeignrdquo compounds whetherthese be natural or synthetic) is associated withusing medicines from natural or syntheticsources
Cytochrome p450 (CYP) enzymes are mixedfunction microsomal mono-oxygenases that arelocated on the smooth endoplasmic reticulum
throughout the body primarily in hepatocytesand in the wall of the small intestine There are12 families and a single hepatocyte can containa range of CYP enzymes that metabolize arange of drugs These CYP enzymes are re-sponsible for phase I (oxidation reduction andhydrolysis) metabolism of a wide number ofcompounds and for transforming lipophilicdrugs into more polar compounds that can beexcreted by the kidneys
Phase II of detoxification occurs if a productconjugates in the hepatocyte cytoplasm withthe tripeptide glutathione The resulting solu-ble compound is excreted via the bile or theurine This conjugation is catalyzed by cyto-plasmic glutathione S-transferases Interindi-vidual variations exist in the concentration of hepatocyte glutathione and in the relative con-centration of individual glutathione S-trans-ferases (Mannervik and Widdersten 1995) andin levels of other compounds that are associ-ated with drug metabolism
CYP2D6 deficiency
Many CYP enzymes are genetically polymor-phic and thus there is marked interindividualvariation in drug metabolism (Wolf and Smith1999) CYP2D6 is one of the most extensivelystudied genetic polymorphisms It is thought tocause much of the individual variations seen indrug responses side-effects and drug interac-tions (Poolsup et al 2000) Individuals may bepoor (slow) metabolizers intermediate exten-sive (fast) or ultrafast metabolizers In a Cau-casian population 7ndash9 of individuals are ho-mozygous deficient in CYP2D6 and are thuspoor metabolizers (Poolsup et al 2000) The in-cidence of CYP2D6 deficiency in Asian popula-tions is 1 and it is thought that much ethnicvariation in drug response is associated withCYP polymorphism (Poolsup et al 2000) Drugsubstrates for CYP2D6 include antidepressantsantipsychotics beta-blockers (eg propanololand antiarrythmics) and several antidepres-sants (Fromm et al 1997) A poor metabolizeris at risk of having adverse reactions if his or herrate of biotransformation is inadequate
If xenobiotics are inadequately metabolizedthey may make covalent bonds with DNA RNAnuclear proteins or cytoplasmic proteins and
DENHAM ET AL248
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
breakdown of function occurs within these cellsWhen this breakdown is above a certain rate theresult of this is damage to the hepatocyte lead-ing to centrilobular necrosis (Kaplowitz 1997)
As noted above Russmann et al (2001) dis-cussed Case 16 in detail It is noteworthy thatthe woman had restarted kava for 3 weeks af-ter an initial course of treatment 2 months ear-lier and then became ill 3 weeks later after anoverdose of alcohol The woman was shown tobe CYP2D6-deficient using phenotyping withdebrisoquine The researchers then tested thepatient who was delineated as Case 10 whichwas described by Strahl et al (1998) and foundthat she was also CYP2D6-deficient Strahl et al(1998) argued that CYP2D6 deficiency is a riskfactor for hepatotoxicity that is ascribed to kava
This finding may help to explain the lack ofhepatotoxicity as a result of kava beingrecorded in the South Pacific Wanwirolmuk etal (1998) tested the phenotypes of 100 personsof pure Polynesian descent using a debriso-quine probe and found a 0 incidence ofCYP2D6 deficiency The researchers proposedthat with regard to this factor Polynesiansstrongly resemble Asian populations
As stated many antidepressants are metab-olized by CYP2D6 and it is likely that using an-tidepressants with kava is not uncommon Yetonly one of the above cases involved antide-pressants which suggests that CYP2D6 defi-ciency is more likely to be relevant than com-petition between CYP2D6 substrates
This finding is significant but difficult to pre-dict because most people are unaware of theirCYP2D6 phenotype It should be noted thatwhen CYP2D6 deficiency occurs use of kavaproducts with enhanced kavalactones mighthave implications for the affecting the liver par-ticularly when a concomitant orthodox medi-cine or substantial amounts of alcohol are takenregularly It is proposed that such risks are likelyto be small if low-alcohol tinctures are usedwithin the normal therapeutic dosage range
RECOMMENDATIONS FROM TMEC
TMEC recommends that
(1) Products made from synthetic kavain are
synthetic drugs not herbal-medicinal prod-ucts and should be excluded from theanalysis
(2) None of the cases cited by the BfArM in-volved traditionally prepared tinctures Inthe light of evidence presented above and byWhitton et al (Appendix 1) the safety ofconcentrated standardized products madefrom acetone extracts and high-alcohol con-centrations needs reevaluation Low-alcoholtinctures appear to provide a safe alterna-tive TMEC recommends adopting extrac-tion methods that use 25 alcohol to ensurethat the full spectrum of constituents is ex-tracted resulting in a substantially lowerconcentration of kavalactones thus ensur-ing kavarsquos safe use as a medicine
(3) Consumers need to be informed that kavaproducts should not be taken together withconventional medicines without the adviceof a health professional Even more impor-tantly consumers need to know that kavashould not be taken without consulting ahealth professional if users have estab-lished histories of liver disease
(4) Maximum doses for kava should be set af-ter consultation with interested parties
(5) Doctors nurses pharmacists and otherhealth professionals should be adequatelyinformed about herbal medicines and pos-sible herbndashdrug interactions (Jobst et al2000)
SUMMARY
The Executive Summary issued by two Ger-man pharmaceutical associationsmdashBundesver-band der ArzneimittelndashHersteller e V (BAH)and Bundesverband der Pharmazeutischen In-dustrie eV (BPI) (see Appendix 3)mdashof theirsubmission to the BfArM concerning kavastated that the causality in most of the reportsis unclear because details such as additionalmedication patient history and consumptionof alcohol are not given ldquothus not permitting asound evaluation of these casesrdquo Schmidt andNahrstedt (2002) noted that a number of thecases have been reported in the literature morethan once with different data including asnoted above case 28 and in particular that
KAVA WORK-IN-PROGRESS 249
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
cases 7 and 8 are the same as are cases 26 and27 The details of the case reports given are alsoat variance with regard to case 4 in which a dif-ferent time before onset is given and inconsis-tencies also occur in cases 23 and 25 in whichthe time before the onset of the two cases is re-versed These discrepancies are unsatisfactoryand undermine confidence in the accuracy andveracity of the information provided by theBfArM It has also been claimed (Schmidt andNahrstedt 2002) that the case reports are notpresented in accordance with European Unionguidelines for adverse-event reports
The BfArM document is deficient in other re-spects too It is unclear whether the term ldquoliverdamagerdquo refers to the results of a liver biopsyor to the finding of raised alanine aminotrans-ferase (ALT) blood levels that are interpretedas indicating damage to hepatocytes in hepa-tocellular disease (Pagana and Pagana 1999)However in light of the need for the UK Com-mittee on Safety of Medicines to make an in-formed decision on these cases this paper en-deavors to interpret the evidence as presentedUnless noted otherwise references to possibledrug-induced hepatoxocity are taken from theBritish National Formulary (BNF) (March 2001)
ACKNOWLEDGMENTS
Thanks to Angela Grunwald for translatinga number of German texts that provided valu-able background for this paper
REFERENCES
Aalbersberg B Kava boom hits the Pacific Med PlantConserv 1999520
Anonymous British Herbal Pharmacopoeia KeighleyUnited Kingdom British Herbal Medicine Association1983
Anonymous Kava only on prescription That would be aloss [editorial in German] Artzte Zeitung 20012012
Bareille M Montastruc J Lapeyre-Mestre M Liver dam-age and NSAID Casendashnon-case study in the FrenchPharmacovigilance Database Therapie 200156(1)51ndash55
Barnes J Anderson L Phillipson J St Johnrsquos wort (Hy-pericum perforatum L) A review of its chemistry phar-macology and clinical properties J Pharm Pharmacol200153(5)583ndash600
Blumenthal M ed The Complete German CommissionE Monographs Austin American Botanical Council1998
Blumenthal M ed Herbal Medicine Revised and Ex-panded Commission E Monographs Austin AmericanBotanical Council 2000
British Medical Association and Royal PharmaceuticalAssociation British National Formulary London Phar-maceutical Press March 2001
Chanwai L Kava toxicity Emerg Med 20002142ndash145Clough A Burns C Mununggurr N Kava in Arnhem
Land A review of consumption and its social corre-lates Drugs Alcohol Rev 200019(3)319ndash323
De Leo V la Marca A Morgante G Lanzetta D Florio PPetraglia F Evaluation of combining kava extract withhormone replacement therapy in the treatment of post-menopausal anxiety Maturitas (Eur Menopause J)200139185ndash188
Edwards I Aronson J Adverse drug reactions Defini-tions diagnosis and management Lancet 20003561255ndash1259
Ellingwood F American Materia Medica Therapeuticsand Pharmacognosy [reprint] Portland OR EclecticMedical Publications 1919
Felter H Lloyd J Kingrsquos American Dispensatory[reprinted 1983] Portland OR Eclectic Medical Publi-cations 1905
Flockhart D Desta Z Mahal S Selection of drugs to treatgastro-oesophageal reflux disease The role of drug in-teractions Clin Pharmacokinet 200039(4)295ndash309
Fromm M Kroemer H Eichelbaum M Impact of p450genetic polymorphism on the first-pass extraction ofcardiovascular and neuroactive drugs Adv Drg DelRev 199727171ndash199
Green R Sites with Lapita pottery Importing and voy-aging Mankind 19749253ndash259
Greenwood-Robinson M Kava New York Dell Publish-ing 1999
Haberlein H Boonen G Beck M-A Piper methysticumEnantiomeric separation of kavapyrones by HPLCPlanta Medica 19976363ndash65
Hansel R Kava-Kava in modern medical practice [in Ger-man] Zeitschrift fuumlr Phytotherapie 199617180ndash195
He X Lin L Lian L Electrospray HPLC-MS in phyto-chemical analysis of kava (Piper methysticum) extractPlanta Medica 19976370ndash74
Hodgson E Levi PE Textbook of Modern ToxicologyStamford CT Appleton amp Lange 1997
Jobst K McIntyre M St George D Whitelegg M Safetyof St Johnrsquos wort (Hypericum perforatum) Lancet 20009203 575
Johnson T CRC Ethnobotany Desk Reference Boca Ra-ton FL CRC Press 1999
Kaplowitz N Hepatotoxicity of herbal remedies Insightsinto the intricacies of plantndashanimal warfare and celldeath Gastroenterology 1997113(4)1408ndash1412
Kubatova A Miller D Hawthorne S Comparison of sub-critical water and organic solvents for extractingkavalactones from kava root J Chromatog A 2001923187ndash194
DENHAM ET AL250
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
Larrey D Hepatotoxicity of herbal remedies J Hepatol199726(suppl1)47ndash51
Lebot V Merlin M Lindstrom L Kavamdashthe Pacific ElixirVT Healing Arts Press 1997
Lebot V Levesque J The origin and distribution of kava(Piper methysticum Forstf and Piper wichmanii C DCPiperaceae) A phytochemical approach Allertonia19895 223ndash280
Lewin L On Piper methysticum kava Archives de Med-icine et de Pharmacie Navale 188646210ndash220
Lindberg M Hepatobiliary complications of oral contra-ceptives J Gen Int Med 19927(2)199ndash209
Loew von D Kava-kava-extract Deutsche ApothekerZeitung 2002142(9)1012ndash1020
Mannervik B Widersten M Human glutathione trans-ferases Classification tissue distribution structure andfunctional properties In Pacifici G Fracchia G edsAdvances in Drug Metabolism in Man Brussels Euro-pean Commission 1995
McIntyre M A review of the benefits adverse eventsdrug interactions and safety of St Johnrsquos wort (Hyper-icum perforatum) J Altern Complement Med 20006(2)115ndash124
Mills S Bone K Principles and Practice of PhytotherapyEdinburgh Churchill Livingstone 2000
Murray W Neoliberal globalisation ldquoExoticrdquo agro-exportsand local change in the islands A study of the Fijian kavasector Singapore J Trop Geog 200021(3)355ndash373
Pagana K Pagana T Mosbyrsquos Diagnostic and LaboratoryTest Reference St Louis CV Mosby 1999
Pittler M Ernst E Efficacy of kava extract for treating anx-iety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Poolsup N Po L Knight T Pharmacogenetics and psy-chopharmacotherapy J Clin Pharm Ther 200025197ndash220
Russmann S Lauterburg B Helbling A Kava hepatotox-icity Ann Int Med 2001135(1)68ndash69
Ruse P Kava-induced dermopathy A niacin deficiencyLancet 19903351442ndash1445
Schmidt M Nahrstedt A Is kava hepatotoxic [in Ger-
man] Deutsche Apotheker Zeitung 2002142(9)1006ndash1011
Schulz V Rational Phytotherapy Heidelberg Springer-Verlag 1997
Spinella M The Psychopharmacology of Herbal Medi-cine Massachusetts MIT Press 2001
Strahl S Ehret V Dahm H Maier K Necrotizing he-patitis after taking a plant medicine Deutscher Medi-zinwochenschrift 19981231410ndash1414
Wanwirolmuk S Bhawan S Coville P Chalcroft S Ge-netic polymorphism of debrisoquine (CYP2D6) andproguanil (CYP2C19) in South Pacific Polynesian pop-ulations Eur J Clin Pharmacol 199854431ndash435
Williamson E Synergy and other interactions in phy-tomedicines Phytomedicine 20018(5)401ndash409
Wolf C Smith S Pharmacogenetics Br Med Bull 199955(2)366ndash386
BIBLIOGRAPHY
Andersson T Pharmacokinetics metabolism and interac-tions of acid pump Inhibitors Focus on omeprazolelansoprazole and pantoprazole Clin Pharmacokinet199631(1) 9ndash28
Kircheiner J Brosen K Dahl M Gram L Kasper S RootsI Sjoqvist F Spina E Brockmuller J CYP2D6 andCYP2C19 genotype-based dose recommendations forantidepressants Acta Psychiatrica Scand 2001104173ndash192
Address reprint requests toAlison Denham BA (Soc) MNIMH
University of Central LancashirePreston PR1 2HEUnited Kingdom
E-mail adenhamuclanacuk
KAVA WORK-IN-PROGRESS 251
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
APPENDIX 1
Response to Reported Hepatotoxicity of High Lactone Extractions of Piper methysticum Forst (Kava)
PETER WHITTON BSc1 JULIE WHITEHOUSE PhD2and CHRISTINE EVANS BSc PhD3
Introduction
This paper (the result of work currently in progress) was produced in response to the reportsby the German BfArM of possible hepatotoxic effects of kava (Piper methysticum Forst) extractsthat has led to concerns regarding the safety of kava products on sale in the United KingdomThere have been thirty cases of hepatotoxicity reported to German and Swiss regulators includingthree transplants and one death allegedly associated with the use of concentrated standardizedkava extracts
In the Oceanic Islands of the South Pacific kava is drunk as an alternative to alcohol or forceremonial purposes and studies have shown in islanders who regularly drink up to ten timesthe recommended therapeutic dose that the only recorded abnormality is a slightly raisedgamma-glutamyltransferase (Barguil 2001)
The analysis presented in this paper based on as-yet-unpublished research by the authors demon-strates the presence of glutathione in the traditional extract which it is postulated may have a he-patoprotective effect Concentrated standardized extracts do not contain glutathione (see below)
Extraction Techniques
In the Oceanic Islands kava is traditionally prepared by macerating the root or root bark ina cold water andor coconut milk solution However in the manufacture of concentrated ex-tracts either ethanol (60 and above) or acetone (60 or above) is used as a solvent to obtainthe maximum yield of kavalactones that have been identified as the ldquoactive constituentrdquo
Research Data (The Result of Work in Progress)
Analysis of kava extraction in different solvents
Kava root was extracted in different solvents and analyzed by high performance liquid chro-matography (HPLC) with diode-array detection Different solvents were used to extract thekavalactones and their extraction is shown in Table 1
The extraction was carried out by reflux percolation for 1 hour for each sample of 5 wvPiper methysticum root The resulting liquids then had their specific gravity and percentage ofdry extract determined by the techniques described in the British Pharmacopoeia (1999) Thetotal kavalactones were measured by HPLC using an acetonitrilewater solvent gradient (Whit-ton 2001)
DENHAM ET AL252
1(Student) School of Biosciences University of Westminster London United Kingdom2University of Westminster London United Kingdom3School of Biosciences University of Westminster London United KingdomPersonal communication from Lamberts Ltd Nottingham United Kingdom
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
Kavalactone standardized extracts are produced using a high acetone or ethanol concentra-tion and are likely to contain only kavalactones and no proteins amino acids or sugars
Further analysis identified one of the other compounds in the aqueous extract and in the 25ethanol extract as glutathione by comparison to a reference sample obtained from Sigma-Aldrich(Poole Dorset United Kingdom)
Samples of commercially available kava extracts were examined and the ratio of kavalactonesto glutathione was calculated the results are shown below in Table 2 and Figure 1
Importance of Glutathione in Kava Extracts
Kavalactones may cause hepatic stress if not mediated by glutathione and are usually me-tabolized in the liver by enzymes called lactone hydrolases (Schmidt et al 1999) It can also bedemonstrated in vitro that kavalactones combine with glutathione in a pH dependant reactionby placing a mixture of kavalactones and glutathione in a test tube and adding 01M of sodiumhydroxide to adjust the pH to between 7 and 10 In the control solution of kavalactones alonein this solution no change occurs The same process is observed when cysteine is used insteadof glutathione This reaction is possibly nonreversible and causes the decolourization of the so-lution This point is important as it shows that the lactone ring structures have been opened andthus changed into other as-yet-unknown compounds The opening of the lactone ring rendersthe complex water-soluble and so it can be absorbed into the gut This may bypass the phase Ienzymatic detoxification pathway in the liver thus causing no depletion of intracellular glu-tathione in the hepatocyte The pH range of this reaction renders it liable to occur in the duo-denum and so most probably occurs in vivo between the kavalactone and the cysteine moiety ofthe glutathione molecule after the glutathione has been broken down to its constituent aminoacids by the gastric enzymes
It could be that the high concentration of kavalactones introduced by concentrated standard-ized extracts has the potential to saturate the enzymatic detoxification pathways resulting in un-due stress on the liver Glutathione has an essential role in the phase II conversion of kavalac-tones into excretable waste products and thus gluathione is relevant in excess dosage of
TABLE 1 EXTRACTION OF KAVALACTONES IN DIFFERENT SOLVENTS SUMMARY OF
RESULTS FOR TEN SAMPLES IN EACH SOLVENT
Extract Kavalactones in dried extract
Acetone extract 10096 Ethanol extract 10025 Ethanol 15Water 297
TABLE 2 KAVALACTONEGLUTATHIONE RATIOS
(RESULTS SUMMARIZED FROM TEN SAMPLES OF EACH TYPE)
Kavalactone content Glutathione content Kavalactoneglutathione Sample (expressed as absorbance) (expressed as absorbance) ratio
Kava standardised extract powder 4031712e6 1346769e3 100003(30 kavalactones) dissolved in 25 ethanol
82 Ethanol extraction 3168906e5 53813e3 1001725 Ethanol extraction (1 part plant 163689e4 188736e4 1115
to 3 parts solvent)25 ethanol extraction (1 part plant 249798e4 51525e4 122
to 1 part solvent)
e napierian logarithm
KAVA WORK-IN-PROGRESS 253
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
kavalactones Glutathione is not soluble in ethanol concentrations above 50 (Merck Index 1996)There has been relevant work on a related group of compounds sesquiterpene lactones It hasbeen demonstrated that sesquiterpene lactones react with the sulfide group on the glutathione mol-ecule in a reversible pH dependent reaction (Schmidt et al 1999) The binding of the sesquiter-pene lactones to the glutathione molecule allows for faster clearance by the lactone hydrolases pre-sent in the hepatocytes (Schmidt et al 2001) It has been demonstrated that oral glutathioneprevents toxicity from sesquiterpene lactones if administered at the same time (Lautermann etal1995) It has also been documented that oral glutathione has to be taken at the time of inges-tion of the kavalactones in order to potentiate the metabolism of the kavalactones
We have shown using Acanthamoeba that when kavalactones are added to the growth mediumthe organisms die rapidly However when the same experiment is carried out using a 5050 mix-ture of kavalactones and glutathione no cell death occurs It was found that no cell death oc-curred in concentrations of the glutathionekavalactone mixture of 50 mgmL whereas cell deathoccurred using kavalactones alone at concentrations of less than 1 mgmL Using photomi-croscopy cell death was assessed via visual criteria of cell movement and cell morphology It isplanned to repeat this procedure using hepatocyte cultures but as the phase I and phase II path-ways are common to most life forms it is considered that these results could show that glu-tathione is indeed required for the metabolism of kavalactones
Glutathione is present in adequate amounts in most cells in the body but some individualscan have a genetic deficiency (Lomaestro and Malone 1995) In these cases high doses of kavalac-tones will lead to rapid depletion in glutathione levels and result in free lactone exposure in thehepatocytes and consequent tissue damage (Zheng et al 2000) Glutathione supplementation(taken orally) has been shown to correct the deficiency (Kidd 1997) It is suggested that the glu-tathione molecule may not be absorbed intact but may be broken down into its constituent aminoacids and regenerated within the hepatocyte
It can be postulated that as the reaction occurs in vitro without the presence of enzymes thebinding of the sulfhydral group of common to the glutathione and the cysteine moiety to thekavalactone may take place in the duodenum before absorption This would allow the same pHeffect as has been seen in vitro and allow the Michael type reaction (Merck Index 1996) to oc-cur It has been demonstrated in vitro (in original research undertaken by the authors) that theaddition of either glutathione or cysteine to kavalactones at a pH between 68 and 100 in anaqueous environment leads to the solubility of the kavalactones with decolourization of the so-lution when compared to the same process without the cysteine or glutathione
DENHAM ET AL254
100
80
60
40
20
096 82 45 25
Kavalactones
Glutathione
FIG 1 Kavalactone and glutathione extraction (expressed as a percentage of dry extract) against ethanol percentagein solvent
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
KAVA WORK-IN-PROGRESS 255
The decolourization strongly suggests that the lactone ring has been opened in this reactionthus making the resultant compound water-soluble This means that this reaction which takesplace without the presence of enzymes can occur in the duodenum This would lead to the ab-sorption of the complex of cysteineglutathione and kavalactone into the hepatocyte withoutputting stress on the phase I pathway and so no depletion of intracellular glutathione wouldtake place This suggests that the liver was able to cope with oxidative stress from other sourceswith no interference from the kava
Previous experiments have been conducted with oral glutathione and acetaminophen (parac-etamol) where no non-enzymatic pathway has been observed These findings are readily ex-plained by the different structural formulae of these compounds (Fig 2)
It can be demonstrated that that the cysteine moiety of the glutathione molecule binds via theMichael reaction to the oxygen atom in the lactone ring with the kavalactones This opens thering and leaves the double-bonded oxygen unit intact As mentioned previously the resultingconjugate is water soluble because of the presence of the thiol group from the cysteine In thecase of acetaminophen (paracetamol) this reaction cannot take place without the presence of thephase I enzymes as the molecule is cleaved at the amine (nitrogen) group in alkaline conditions(as the authors have demonstrated) This is quite possibly the reason why large doses (ten tofifty times the therapeutic dose of 60ndash120 mg per day) of the traditional kava extract have beenshown not to cause hepatic damage whereas the standardized concentrated extract has been as-sociated with these cases
Another strong piece of evidence that the kavalactones may be moderated by other compo-nents in traditional use comes from the epidemiologic studies carried out in Arnhem Land in
FIG 2 Chemical stuctures of (A) glutathione (B) kavalactones (C) acetaminophen and (D) cysteine
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
DENHAM ET AL256
the Northern Territories in Australia These preliminary studies have found no evidence of liverdamage in individuals who habitually ingest kava extracts equivalent to between ten and fiftytimes the daily therapeutic dose (60ndash120 mg) of kavalactones per day
Summary
Kavalactones are normally metabolized by lactone hydrolases which are enhanced by thepresence of glutathione
Glutathione naturally occurs in kava in a 11 ratio with kavalactones and is likely to reducethe likelihood of potential lactone toxicity In contrast to the traditional crude extract stan-dardized extracts contain no glutathione while containing up to 30 times the kavalactone con-centration
It appears that the high kavalactone in concentrated standardized extracts may deplete the re-serves of glutathione in the hepatocytes which could result in liver damage It would thereforeseem prudent to limit the organic solvent level in the extraction of kava to 25 ethanol in orderto ensure the preservation of the hepatoprotective effect of the glutathione Tinctures made with25 ethanol would appear to be safe as a result of this synergistic effect of the glutathione andkavalactones
Conclusions
Traditional preparations have had many years of safe usage (Norton and Ruse 1994) and tox-icity has only been reported in Europe with concentrated standardized extracts (Escher et al2001)
This paper argues that there are significant differences between concentrated extracts and thoseproduced by traditional methods that maintain a satisfactory ratio between glutathione andkavalactones In traditional extracts ratios of at least 11 kavalactoneglutathione should providea safe product with hepatoprotective action It would appear that glutathione has an importantsynergistic action in protecting the liver from potential lactone toxicity
This study suggests that standardized herbal extracts which do not contain all components ofthe traditional plant extract may have a potential to induce hepatotoxicity in susceptible people(eg those taking concomitant orthodox medicines) It is proposed that tinctures manufacturedusing a traditional cold-maceration process (in 25 ethanol and 75 water) that is more nearlyapproximate to traditional water or coconut milk extracts or raw plant material are safe in nor-mal subjects
REFERENCES
Barguil Y Rapid responses Kava and gamma-glutamyltransferase increase Hepatic enyzmatic induction or liverfunction alteration [letter in response to Escher et al 2001] eBMJ March 21 2001 Online document at httpbmjcom
British Pharmacopaeia Commission London The Stationery Office 1999Budavari S Merck Index Monograph 4483 Twelfth Edition Rahway NJ Merck and Co 1996Escher M Desmeules J Giostra E Drug points Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Kidd MD Altern Med Rev 19972(6)155ndash176
Epidemiological studies on kava use and side effects in Arnhem Land Aborigines Menzies University PersonalCommunication Personal communication with Alan Clough of Menzies University Darwin Northern Territory Aus-tralia 2002
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
KAVA WORK-IN-PROGRESS 257
Lautermann J McLaren J Schacht J Glutathione protection against gentamicin otoside effects depends on nutritionalstatus Hearing Res 199586(1ndash2)15ndash24
Lomaestro BM Malone M Glutathione in health and disease Pharmacotherapeutic issues Ann Pharmacother1995291263ndash1273
Norton SA Ruze P Kava dermopathy J Am Acad Dermatol 19943189ndash97Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene Bioorganic Med Chem 200192189ndash2194Schmidt TJ Lyszlig G Pahl HL Merfort I Helenanolide type sesquiterpene lactones Part 5 The role of glutathione ad-dition under physiological conditions Bioorganic Med Chem 19997(9)2849ndash2855
Whitton PA Rapid Responses to Letters page eBMJ March 2001 Online document at httpbmjcomZheng XG Kang JS Kim HM Jin GZ Ahn BZ Naphthazarin derivatives (V) Formation of glutathione conjugate andcytoside effects activity of 2-or 6-substituted 58-dimethoxy-14-napthoquinones in the presence of glutathione-S-transferase in rat liver S-9 fraction and mouse liver perfusate Arch Pharmacol Res 20002322ndash25
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
APPENDIX
2
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatic findings
Concomitant drugs
Notes
169
f
23
200 mg of
Data missing
Data missing
Cho
lestatic hep
atitis
ASS
deh
ydrosano
lRecov
ered
hep
atic side-effects
synthe
tic
Ren
tylin
adescribed
for all co
ncom
itan
t ka
vain
med
ications
235
m
23
200 mg of
Anx
iety states
Anx
iety states
Cho
lestatic hep
atitis
Data missing
Recov
ery after disco
ntinua
tion
synthe
tic
kava
in3
68f
33
70 m
gd
Data missing
Data missing
Increa
sed liver
Data missing
Data missing
of acetone
en
zymes (present
extract)
before beg
inning
kava
med
ication)
439
f
33
70 m
gd
Dep
ressive
4 ye
ars
Upp
er abd
ominal
Diazepam
aRecov
ery after disco
ntinua
tion
of all
of acetone
neur
osis
pressure na
usea
Gravistata
med
ications
hep
atotox
icity also
extract
vomiting icterus
L-Thy
roxin
know
n for the co
ncom
itan
tmed
ications
568
f
33
70 m
gd
Dep
ressive
2 ye
ars
Cho
lestatic hep
atitis
Neu
roplan
t forte
aRecov
ery after 97
day
s spo
radic
of acetone
emotiona
licteru
sMaa
loxa
naif
notification
s of inc
reased
liver
extract
deterioration
requ
ired
param
eters und
er M
aaloxa
na6
50f
33
70 m
gd
Data missing
2 mon
ths
Increa
sed liver
Teldan
eaaten
olol
Hep
atic side-effects also described
for
of acetone
enzy
mes liv
erHyd
rotrix
aconc
omitan
t med
ications
extract
cell-im
pairmen
tacute hep
atitis
with icteru
s 7
72f
Phy
to-
Data missing
6 mon
ths
Jaun
dice cho
lestatic
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
875
f
Phy
to-
Data missing
2 ye
ars
Cho
lestatic hep
atitis
Eun
ovaa
No he
patic side-effects kn
own for
Geriatrikum
ahe
patitis liver-cell
conc
omitan
t med
ication
(with 25
mg
impairm
ent
dry extract
with etha
nol)
981
f
23
60 m
g of
Anx
iety
9 mon
ths
Tox
ic hep
atitis w
ith
HCT-isis 12
5
Exitus seldom
ly icterus
und
er hyd
ro-
etha
nol
restlessne
ssliv
er failure acute
Cralonin Tra
chlorothiazide he
patic im
pairmen
t by
ex
tract
yello
w liver
Bay
oten
sina
alco
hol no
t ex
clude
ddys
trop
hy( bis
198
)
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
1039f
60 m
gd
Data missing
6 mon
ths an
dSe
vere hep
atitis w
ith
Paroxe
tin St John
rsquosRecov
ery after 8 3 weeks
hep
atic
14 day
s after
confluen
t ne
cros
iswort if req
uired
side-effects described
for hormon
alreex
posu
reho
rmon
al ovu
lation
ovulation
inh
ibitors
inhibitors for 6 yea
rs11
59f
23
120 mg
dAnx
iety states
4 mon
ths
Live
r-cell im
pairm
ent
Bus
copan
aSp
orad
ic notifications
of he
patic side-
effects und
er Buscop
ana
1237f
23
70 m
gd
Data missing
Data missing
Hep
atitis
Microdiola
sinc
e Recov
ery after 3 mon
ths hep
atic side-
of acetone
5 ye
ars 2
3effects also kno
wn for co
ncom
itan
tex
tract
diclofena
c IM
med
ications
1362f
Ethan
olData missing
Data missing
Live
r-cell im
pairm
ent
Non
e den
oted
No med
ical m
essage
extract
1433f
Ethan
olData missing
4 mon
ths
Bilir
ubina
emia
Cisap
ride
Hep
atic side-effects also described
for
extract
hepa
titis inc
reased
conc
omitan
t med
ication
liver enz
ymes
cirrho
sis of the
liver
1546f
Data missing
Data missing
Data missing
Seve
re liver dam
age
Prop
anolol HCT
Hep
atic side-effects also described
for
with icteru
sValsartan
aco
ncom
itan
t med
ications
1633f
33
70 m
gd
Data missing
Data missing
Cho
lestatic hep
atitis
13
60
g alcoho
lRecov
ery after 6 weeks
of acetone
with icteru
sex
tract
1760f
70 m
gd of
Dep
ression
Data missing
Increa
sed biliru
bin
Celecox
ibRecov
ery after 2 weeks
he
patic side-
aceton
e-an
d tran
saminases
effects also kno
wn for co
ncom
itan
tex
tract
indolen
t icteru
smed
ication
1850m
3ndash4
370
mg
Nervo
us2 mon
ths
Acu
te necrotizing
Alcoh
ol m
oderately
Trans
plantation notifications
of he
patic
of acetone
-tens
ion
hepa
titis irrev
ersible
1ndash2
3 paracetam
ol
side-effects und
er paracetam
ol exist
extract
liver dam
age
Nachtke
rzen
samen
ola
1921f
8ndash10
350
mg
Data missing
2 mon
ths
Increa
sed liver
Pasp
ertina
Side-effects also
kno
wn for co
ncom
itan
ten
zymes jaund
ice
Pan
toprazo
le
med
ications
hepa
titis
paracetam
ol
Basiliku
m-Tropfen
a
2050f
60 m
gd of
Stress states
7 mon
ths
Fulm
inan
t liv
erAmaryl
a G
luco
pha
geTrans
plantation hep
atic side-effects
etha
nol
failu
reSa G
ravistat
aalso kno
wn for Amaryl
a(cho
lestasis
extract
follo
wed
by
hepatitis) an
d K
limon
orm
aas w
ell as
Klim
onorm
aGravistat
a(tum
ors of the
liver
cholestasis anicteric hep
atitis)
2122f
23
120 mg of
Nervo
usn
ess
5 mon
ths
Necrosis com
plete
Max
alat
a(if
Trans
plantation hep
atic side-effects also
etha
nol-
anxiety states
destruc
tion
of
requ
ired
) Praminoa
know
n for Pr
aminoa
(tumors of the
extract
endog
enou
sthe paren
chym
a(beforeh
and V
alette
a )liv
er ch
olestasis anicteric hep
atitis)
dep
ression
fulm
inan
t liv
erfailu
re22
34f
120 mg
d of
Data missing
3 mon
ths
Hep
atitis increased
Jodthyrox
aRecov
ery after disco
ntinua
tion
of ka
vadr
y ex
tract
liver enz
ymes
med
ication sporad
ic notifications
of
with etha
nol
hepatic side-effects und
er Jod
throx
2334f
120 mg
d of
Data missing
1 mon
thIncrea
sed liver
paracetamol
Notifications
of he
patic side-effects
etha
nol
enzy
mes jaund
ice
und
er paracetam
olex
tract
( continued)
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
APPENDIX
2 (Con
tinu
ed)
Case Rep
orts as Analyz
ed by the German
Fed
eral Institute for D
rugs and M
edical Products
(the German
BfA
rM) C
ircu
lated in N
ovem
ber 200
1
Timeframe
Patient
(beginning of
(agegender)
treatment reactions
(f5female
to first occurrence
Identifierm
5male)
Dose
Indication
of symptoms)
Hepatotoxic adverse drug
Concomitant drugs
Notes
2447
f
Antares
a12
0Data missing
1 mon
thIncrea
sed liver
Fischo
lkap
seln
aRestored to he
alth after disco
ntinua
tion
etha
nol-
enzy
mes
ofco
ncom
itan
t med
ication an
dex
tract
continuationof A
ntares
a -med
ication
2535
f
Ethan
ol-
Data missing
3 mon
ths
Hep
atitis increased
Hyp
ericum
Restored to he
alth n
o he
patic side-
extract
liver enz
ymes
caps
ules
effectsk
nown for co
ncom
itan
tmed
ication
2638
m
Acetone
Data missing
2 weeks
Liver-cell
Penicillin-V
aNo he
patic side-effects kn
own for
extract
impairm
ent
conc
omitan
t med
ication
2739
m
70 m
gd of
Data missing
2 weeks
Liver-cell
Non
eData missing
aceton
e im
pairm
ent
extract
28Age
not
Kav
ain
Data missing
Hep
atitis
L-Thy
roxine
Recurren
ce of he
patic side-effects
provided
Lorza
araplus
hepatic side-effects also kno
wn for
f
Estrage
staPflastera
conc
omitan
t med
ications
Antra M
UPS
a
2960
f
Up to 48
0Dep
ressive
1 ye
arFu
lminan
t liv
eretile
frin-H
CL
Trans
plantation spo
radic notifications
mg
d of
emotiona
lfailu
repiretan
idof hep
atic side-effects und
er piretan
idetha
nol
deterioration
extract
3032
m
24
0 mg
dRestlessn
ess
3 mon
ths
Necrotizing
hep
atitis
Baldrian
aEva
luation of the
necessity for
of ethan
olwith insu
fficienc
y (occasiona
lly)
tran
splantation
extract
of the
liver m
etab
olic-
toxic-allergic dru
gdam
age
a Information on
gen
erics m
anufacturers a
nd lo
cation
s were no
t provided
for brand
-nam
e dru
gs
Sour
ce A
ppe
ndix of a letter sen
t to participan
ts in
a step-by-step
plan an
d cop
ied to the Med
icines C
ontrol A
genc
y w
hich
cop
ied the
letter to orga
niza
tion
s on
its co
n-su
ltation lis
t The
letter was entitled ldquoHea
ring
stage
II 71
71-A
-306
46 679
1800-339
0 dru
gs con
taining ka
va-kav
a ( Piper methysticum
) an
d kav
aine
inc
luding ho
meo
pathic
remed
ies with a fina
l con
centration
up to D6rdquo
IM intramuscular
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
APPENDIX 3
Executive Summary Issued January 18 2002 by the Bundesverband derArzneimittelndashHersteller e V (BAH) and Bundesverband der Pharmazeutischen
Industrie eV (BPI) Comments of BAHBPI on the BfArM Letter of November 8 2001 on Kava- and Kavain-Containing Medicinal Products
Executive Summary
On December 18 2001 the BAH and BPI the German pharmaceutical trade associations sub-mitted a statement to BfArM the German health authority on behalf of German kava manu-facturers subsequent to a letter from BfArM of November 8 2001 The industryrsquos statementcomes to the conclusion that the presented data on the benefitrisk assessment of kava- andkavain-containing medicinal products do not justify the withdrawal of marketing authorisationsThe companies already included risk information in their package leaflets and expert informa-tion at their own responsibility and consider control of patients applying kava products by aphysician as an appropriate means of ensuring safe usage
In particular in most of the reported cases the causality between kava intake and liver reac-tions is not clear because further medication was used which might have caused liver toxicityIn many cases detailed information on the patientsrsquo history co-medication consumption of al-cohol and further particulars are missing thus not permitting a sound evaluation of these casesRegarding clinical efficacy there are placebo-controlled and reference-controlled clinical stud-ies as well as open studies which demonstrate an improvement of symptoms in conditions ofnervous anxiety stress and restlessness
Data on the Risk Assessment
The report published by Kraft et al (2001) describes liver failure in a 60-year-old female patientwho took a kava preparation in an amount up to four times of the recommended daily dose Livertransplantation was required Due to further medication containing piretanid and etilefrin whichmight have caused liver-related side effects kava is unlikely to be the only cause of the side effect
The case report published by Brauer et al (2001) describes liver failure in a 22-year old femalepatient Liver transplantation was required Since the patient also took rizatriptan and oral con-traceptives which might have liver-related side effects kava is unlikely to be the only cause ofthe side effect
The case report published by Sass et al (2001) describes a 50-year old female patient who tookkava for seven months in a daily dose of 60 mg kavapyrones She experienced a hepatic comaliver transplantation was required Glimepirid and estradiol were used as co-medication Acausal connection between the liver effect and kava intake cannot definitely be excluded How-ever contribution by the co-medication to the side effect seems possible
A further case report on kava (Strahl et al 1998) describes a necrotising hepatitis in a 39-yearold female patient with positive re-exposition During the first application of the kava productan oral contraceptive as well as paroxetin were used A causal relationship with kava cannot beexcluded but the patientrsquos history and a potential pre-existing liver damage must be taken intoaccount In addition the kava preparation used was not identified by the physician
In additional reports from Switzerland Escher et al (2001) and Stoller (2000) describe twocases a liver transplantation in a 50-year old female patient using also evening primrose oil ayeast preparation and paracetamol as well as liver symptoms in a 33-year old patient who alsoapplied propyphenazon and paracetamol and consumed alcohol
KAVA WORK-IN-PROGRESS 261
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
DENHAM ET AL262
Most of the other case reports (not quoted by BfArM) cannot be assessed since essential dataare missing or they have to be evaluated as ldquoimprobablerdquo or ldquoquestionablerdquo
Data on the Benefit Assessment
According to a meta-analysis performed by Pittler and Ernst (2001) therapeutic equivalenceof kava and synthetic anxiolytics can be assumed
For an extract prepared with acetone as [a] solvent there are seven randomised placebo-con-trolled double blind studies as well as one randomised reference-controlled double blind studyperformed between 1991 and 2001 They demonstrate the efficacy of the kava extract in condi-tions of nervous anxiety stress and restlessness
On various ethanolic extracts the following data are available
A three-arm double-blind clinical study in 127 patients versus opipramol and buspirone inorder to prove efficacy in general conditions of nervous anxiety
A non-interventional study in 1187 patients confirming these results and demonstrating goodtolerability
A pharmacodynamic study versus bromazepam and placebo showing relaxing and anxiolyticeffects of a kava extract as well as better tolerability than bromazepam
An in-vivo experiment (elevated plus maze test in rats) showing a remarkable anxiolytic ef-fect of a kava extract comparable to that of diazepam
A randomised controlled double-blind study in 69 patients demonstrating improvement ofthe total Hamilton Anxiety Scale score as well as for the score for [psychologic] and somaticanxiety at a dose of 200 mg kavapyrones daily
A study demonstrating a tranquillising effect (comparable to benzodiazepines) in conditionsof anxiety prior to medical surgery
A non-interventional study in 3338 patients demonstrating a remarkable decrease in symp-toms of anxiety after an average duration of therapy of 25 months
An observational study in 52 patients showing a decrease of anxiety-related symptoms An observational study including 30 patients with psycho-somatic complaints which demon-
strated improvement Further experiments with a lower number of patients as well as a non-interventional study
currently being performed including 131 patients
As a result of their proven clinical efficacy kava preparations were included in the draft pos-itive list issued by the German ministry of health in July 2001 According to this draft list kavaproducts are reimbursable by the state health insurance like chemical substances used in this in-dication field
Conclusion
Conditions of nervous anxiety stress and restlessness must be regarded as wide-spread dis-orders which without treatment might have severe [psychologic] and social consequences andfor this reason require medical treatment In case kava products are withdrawn from the mar-ket only chemical substances would be available as therapeutic alternatives eg benzodi-azepines anxiolytics anti-depressants neuroleptics et cetera Yet all these substances have
Note added An indication field is a range of indications for example anxiety for reimbursement under the statemedical system in Germany
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263
many side-effects including liver toxicity Benzodiazepines as an alternative have a high po-tential of addiction
Available data on the benefitndashrisk assessment of kava and kava-containing medicinal prod-ucts do not justify the withdrawal of the respective marketing authorisations Inform[ing] the patient by package leaflets as well as expert information and [supervision] of patients by aphysician are regarded as an appropriate means [using kava]
REFERENCES
Brauer R Pfab R Becker K Berger H Stangl M Fulminan liver failure after taking the plant remedy kava-kava [PosterAbstract] 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash30 2001
Kraft M Spahn T Menzel J Senninger N Dietl K-H Herbst H Domschke W Lerch M Fulminant liver failure aftertaking the plant antidepressant kava-kava Deutsche Medizin Wochenschrift 2001126970ndash972
Pittler M Ernst E Efficacy of kava extract for treating anxiety Systematic review and meta-analysis J Clin Psy-chopharmacol 200020(1)84ndash89
Escher M Desmeules J Giostra E Mentha G Hepatitis associated with kava a herbal remedy for anxiety BMJ2001322139
Sass M Scnabel S Kroger J Liebe S Schareck W Acute liver failure caused by kava-kavamdasha rare indication for livertransplant 12th Workshop for Experimental and Clinical Liver Transplantation and Hepatology Wilsede GermanyJune 28ndash302001
Strahl S Ehret V Dahm H Maier K Necrotising hepatitis after taking medicinal plants Deutsche Medizin Wochen-schrift 19981231410ndash1414
Stoller R Liver damage whilst taking kava extracts Schweizerische Arztezeitung 200081(24)1335ndash1336
KAVA WORK-IN-PROGRESS 263