Daniel S. Sitar, BScPharm, PhD, FCPProfessor Emeritus

University of Manitoba

May 3, 2010

OBJECTIVESTh di ill k th d The audience will know the drugs available without prescription to manage modest pain conditionsTh di ill d t d th The audience will understand the differences among them that may affect choiceTh di ill k hi h The audience will know which preparations they should not useThe audience will be aware of the fact th t b d d t l that brand name drugs are not always the same when purchased in Canada vs the USA

OVER-THE-COUNTER DRUGSAcetylsalicylic acid

(Aspirin in many other countries)Acetaminophen

(Paracetamol in the UK)IbuprofenNaproxenCombination products

ANALGESIC PROPERTIESAll of these over-the-counter drug preparations are analgesic, anti-inflammatory and antipyretic

EXCEPT

Acetaminophen

PAIN MANAGEMENTPAIN MANAGEMENT

Health and Welfare Canada 1984

DOSE INGESTION PRINCIPLEThe faster you can get the drug into the intestines the more rapid will be the

t f l i ffionset of analgesic efficacy

C ld l ti l t t i t iCold solutions accelerate gastric emptying

Absorption with an empty stomach will Absorption with an empty stomach will provide the fastest onset of analgesia

ACETYLSALICYLIC ACID

Plain vs. Enteric-Coated Acetylsalicylic Acid

Biopharm Drug Disposit 1986;7:21

SALICYLATE INGESTION ISSUESTake with a glass of cold water (6 – 8 oz)For recurrent pain a single starting For recurrent pain, a single starting dose of 650 mg should be the minimum ingestionDo not take enteric-coated salicylate for acute pain conditionsA dose of 975 mg every 12 hours is a A dose of 975 mg every 12 hours is a reasonable dose strategy to treat chronic pain that is responsive to acetylsalicylic acidacetylsalicylic acid

NEW EVIDENCE FOR NEW EVIDENCE FOR SALICYLATE EFFICACY

A single 1000-mg dose of aspirin is an effective treatment of acute migraine headaches for more than half of people who take itC d ith l b i i Compared with placebo, aspirin reduced associated symptoms of nausea vomiting photophobia and nausea, vomiting, photophobia, and phonophobia

Cochrane Database Syst Rev. Posted online April 14, 2010.

ACETAMINOPHEN

Lack of acetaminophen ceiling effectLack of acetaminophen ceiling effect on RIII nociceptive flexion reflex

(Eur J Clin Pharm 1998)(Eur J Clin Pharm 1998)

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Placebo 500 mg 1000mg 2000mgAcetaminophen Dose (i.v.)

ACETAMINOPHEN INGESTION ACETAMINOPHEN INGESTION ISSUES

A dose of 500 mg should be the lowest ingested. No more than 1000 mg should be ingested at any one timebe ingested at any one time.Ingest with 6 – 8 oz of cold waterFor chronic pain, dose ingestion should For chronic pain, dose ingestion should be repeated every 6 hoursIn contrast to salicylate, efficacy is not y , ysignificantly prolonged by increasing the dose

IBUPROFENIBUPROFEN

IBUPROFEN DOSE ISSUESThe starting dose should be 200 – 400 mg every 4 – 6 hours, but no more than 1200 /d1200 mg/dayOnly half of the dose contains active ddrugTake with a glass of cold water (6 8 )(6 – 8 oz)Less effective for pain states that do

t h i fl t tnot have an inflammatory component

NAPROXENNAPROXEN

NAPROXEN DOSE ISSUESThis drug has only recently become available without a prescription in CanadaCanadaDo not take more than one tablet every 12 hours without consulting a physiciang p yTake with a glass of cold water (6 – 8 oz)( )In contrast to ibuprofen, all of the drug in this preparation is active

Bandolier website

OTC DRUG PREPARATIONS NOT OTC DRUG PREPARATIONS NOT TO BE USED

No ibuprofen with low dose acetylsalicylic acidNo over-the-counter analgesic preparations containing codeineNo concurrent use of different NSAIDsIf you are taking low-dose

t l li li id f di l acetylsalicylic acid for cardiovascular prophylaxis, the only safe analgesic is acetaminophenacetaminophen

RECOMMENDED COMPUTER RECOMMENDED COMPUTER WEBSITE

***Bandolierhttp://www.medicine.ox.ac.uk/bandolier/booth/painpag/index2.html

Health CanadaNot user friendlyNot user friendly

FDANot user friendlyNot user friendly

COMORBIDITIES THAT COMPLICATE PAIN MANAGEMENT

High blood pressureBlood coagulation modifiersHeart failureKid diKidney disease

Please see your health care worker for Please see your health care worker for acceptable pain management strategies. Acetaminophen is likely to be the first drug chosenchosen

SUMMARY DRUG FACTSIbuprofen is a mixture of two chemicals, only one of which reduces pain. Some people can convert the inactive form to the active formAcetaminophen will not work well for pain caused by inflammationCaffeine will increase the efficacy of OTC Caffeine will increase the efficacy of OTC drugs sold to treat painDifferent drugs have different durations of

tiactionFor persistent pain, drug doses should be taken at scheduled times and not only when ypain is severe.

Caffeine as a Co-analgesic• Caffeine will increase the analgesic effect of all Caffeine will increase the analgesic effect of all

nonopioid analgesic drugs

• The required dose for a co-analgesic effect is 60-120 The required dose for a co analgesic effect is 60 120

mg

• Patients who ingest foods and beverages that contain Patients who ingest foods and beverages that contain

caffeine may already be benefiting from the co-

analgesic effectg

• Caffeine withdrawal is a major contributor to sudden

onset of headache

COMBINATION DRUG COMBINATION DRUG PRODUCTS

These are usually marketed as brand namesThe same brand in Canada ma not The same brand in Canada may not have the same ingredients as that marketed in the USA – e.g. Excedrin®g

READ THE LABEL FOR THE LIST OF INGREDIENTS

The only rational combinations are any of the dr gs mentioned toda ith of the drugs mentioned today with caffeine or acetaminophen with any one of the other NSAIDs +/- caffeine