the story of penicillamine: a difficult birth

Historical Review

The Story of Penicillamine: A Difficult Birth

John M. Walshe, DSc, MD*

Department of Neurology, The Middlesex Hospital, London, United Kingdom

“As the doctor says of a wasting disease, to start with it is easy to cure but difficult to diagnose; after a time, unless it has beendiagnosed and treated at the outset, it becomes easy to diagnose but difficult to cure.”

—Niccolo Machiavelli, The Prince, 1514 (trans George Bull)

It is often said, somewhat cynically, of a newly intro-duced drug, “use it while it still works.” With penicilla-mine the opposite was the case. This chelating agent,introduced in 1956,1 not only revolutionised the treat-ment of Wilson’s disease, but subsequently found a usein the management of cystinuria and rheumatoid arthritis.Penicillamine, �� dimethyl cysteine, was originally de-rived from penicillin by hydrolysis breaking the lactamring. In the first description of this molecule by Abrahamet al.2 in Oxford, the sulphur atom was mistaken for twooxygens, so the important sulphydryl group, whichmakes the molecule active as a chelating agent, wasmissed. Naturally occurring is the D isomer. That the L

isomer is toxic was shown as early as 1950 by Wilsonand Du Vigneaud3 in the United States.

My interest in this compound arose coincidentallywhile working in Charles Dent’s laboratory in UniversityCollege Hospital, London (Fig. 1) in the early 1950s. Inthe course of a survey into disturbances of aminoacidmetabolism in patients with liver damage, using thenewly introduced technique of paper chromatography, Iobserved a new ninhydrin reacting compound in theurine of a patient who had undergone left hepatic lobec-tomy for the removal of a small, well-localised hepatoma(Fig. 2); this metabolite had not been present in the urinepre-operatively. There seemed to be three possiblecauses for the appearance of this new compound, whichhad not been previously recorded in human urine. Was it

due to the anaesthetic, to the trauma of surgery, or to lossof liver tissue leading to a disturbance of liver function?

It was at once apparent that the new compound was asulphur aminoacid because its position on the chromato-gram was altered by oxidation. The use of various sol-vent systems suggested the formula had to be dimethylcysteine. When I put this hypothesis to him, ProfessorDent at once recognised that this new compound waspenicillamine. Further studies showed that the unknowncompound and penicillamine behaved identically withthe various solvent systems I had employed, becausewhen a reference sample penicillamine was added to theurine it moved to the same place on the chromatogram asthe unknown compound. A study of the patient’s notesrevealed that he was being treated with penicillin at thetime that the unknown compound appeared. Giving my-self a large dose of intravenous penicillin (the standardroute of administration at that time), I found that I alsoexcreted penicillamine, as did one of my colleagues whovolunteered for the test.

It then became possible to collect sufficient urine toisolate the new compound using an ion exchange resinand to prove its composition by elementary analysis. Inaddition, the unknown compound reacted with ferricchloride to give a blue colour, thereby confirming thepresence of an -SH group and demonstrating that peni-cillamine liberated in the body by penicillin breakdownwas not auto-oxidised to ��, �� tetramethyl cystine.(These important observations were included in an MDthesis that was rejected by the University of Cambridge!)

There the matter may well have rested, as soon after Imoved to the liver unit, led by Dr. Charles Davidson inthe Thorndike Memorial Laboratory at Boston City Hos-pital. Also active in the City hospital was Dr. Denny-

*Correspondence to: Dr. J.M. Walshe, 58 High Street, HemingfordGrey, Huntingdon, Cambs PE28 9BN, United Kingdom.

Received 20 December 2002; Accepted 6 January 2003

Movement DisordersVol. 18, No. 8, 2003, pp. 853–859© 2003 Movement Disorder Society

853

Brown who together with Dr. Uzman, was working onWilson’s disease. Denny-Brown’s role in the early use ofBritish Anti-Lewinte (Dimercaprol, BAL) has recentlybeen described,4 but the part played by Uzman was notsufficiently stressed. Uzman had developed a theory thatWilson’s disease was due to a disturbance of aminoacidor peptide metabolism, abnormal “oligopeptides” beingpresent in the urine,5,6 a finding that it has never beenpossible to replicate.7 I heard later that the family studiedby Uzman may well not have been suffering from Wil-son’s disease at all, but this was never confirmed. Ac-cording to this theory, copper was not the toxic factorcausing cell death in Wilson’s disease, but it was simplydeposited as a secondary phenomenon in necrotic tissue.How this theory could be reconciled to the use of Dimer-caprol for the treatment of Wilson’s disease by removing

copper is difficult to understand, but somehow Denny-Brown and Uzman managed to do so. Indeed, Denny-Brown became fiercely attached to the use of Dimerca-prol, as will become apparent later.

During the course of my year at Boston City HospitalI read a wonderful paper by Cartwright and his group inSalt Lake City.8 They detailed the various disturbancesof copper metabolism in patients with Wilson’s diseaseand discussed the different treatments then available:BAL (Dimercaprol), EDTA (Versene), aminoacid sup-plements, and steroids. It was apparent that none of thesewere entirely satisfactory, Dimercaprol being the mosteffective, but its use limited by the painful nature of theinjections, frequent toxic reactions, and eventual tachy-phylaxis. It was shortly after this that Denny-Brownsought Davidson’s advice on managing liver failure inone of the Dimercaprol-treated patients (Joe G); adviceon the general management of his Wilson’s disease wasnot sought.

As we walked back from Neurology to the liver unit(Fig. 3), I suggested to Davidson that penicillaminemight have the correct formula to act as a copper-remov-ing drug. He immediately took up the idea and obtainedfor me 2 g of penicillamine from Professor John Shee-han, who was working on the chemical synthesis ofpenicillin at the Massachusetts Institute of Technology.There was no published information about the toxicologyof penicillamine in man and little in animals apart fromDu Vigneaud’s earlier work in which he showed that theL isomer was toxic to growing rats. However, I wasencouraged by my own observations that anyone treatedwith penicillin excreted penicillamine in the urine, ap-

FIG. 1. University College London Hospital from University Street,1952.

FIG. 2. Paper chromatogram to displayurine aminoacids; solvents, phenol/waterright to left, collidine/lutidine upwards, de-veloped with ninhydrin. The pencillaminespot, after oxidation with hydrogen peroxide,is shown by the arrow; it comes betweencysteic acid and taurine.

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Movement Disorders, Vol. 18, No. 8, 2003

parently without ill effect. Theoretically, therefore, it wassafe, and I took the first gram myself; this was a crys-talline powder with an offensive sulphurous smell. Theeasiest way to take it seemed to be to dissolve it in tapwater, but to my horror when I added tap water, it turnedbright blue. After a moment’s thought I realised that thiswas the ferric chloride reaction from rust in the pipes. Iswallowed this noxious brew and to my relief, was still

alive and well the next morning. The stage was thus setfor a clinical trial.

Fortunately, in those early days, there were no ethicalcommittees and no FDA to stop the march of progress. Idoubt very much whether in the present climate of opin-ion such a trial would have been permitted, to the even-tual detriment of all those patients with Wilson’s diseasewho have subsequently been saved by this drug. Buoyedup by my own experience, I gave the second gram to JoeG, who also survived the experiment without ill effectand showed a very satisfactory increase in his urinarycopper excretion, suggesting that further studies withpenicillamine would be justified: what was needed wasmore penicillamine. Davidson had contacts at Merck,Sharp and Dohme (MSD) whom he thought might sup-ply some and this they subsequently did. Several gramsarrived with some preliminary toxicity tests on rats thatproved satisfactory as far as they went. But all was not

FIG. 3. “The Bridge” at Boston City Hospital in 1955, crossing thecentral courtyard and joining the Neurology Unit to the ThorndikeMemorial Laboratory, on the left.

FIG. 4. The chemical formulae of (a) penicillamine, dimethyl cys-teine, thiovaline; (b) oxidised penicillamine, tetramethyl cystine; and(c) BAL, 2.3 dimercaptopropanolol.

FIG. 5. S.F. when first seen in December 1955, before the start oftreatment. She was the first patient ever to be treated with penicillamineand has now been taking it for 47 years.

STORY OF PENICILLAMINE 855


straightforward: this new supply failed to induce theexpected cupriuresis. Had the first study produced afalse-positive result from contamination of the urine withtraces of copper? This did not seem unlikely. Sadly I saidto myself, “There goes my Nobel prize!” Then I remem-bered the blue colour reaction that penicillamine giveswith ferric chloride; I tested the MSD preparation andfound that the blue did not develop, the test was not evenweakly positive. The likely explanation was that on longstorage the penicillamine, dimethyl cysteine, had auto-oxidised to tetramethyl cystine thereby losing its sulphy-dryl radical and the ability to chelate copper (Fig. 4).MSD assured me that this was not the case. I repliedsuggesting they try the ferric chloride reaction and theywere forced to admit that my hypothesis was correct.However, they hoped “this would not interfere with myresearch.” No thanks to them, it did not. Professor Shee-han put me in touch with a firm in New York, Mann’sFine Chemicals, who promised 50 g of penicillamine

thiazolidine from which it would be possible to free thepenicillamine by acid hydrolysis. This compound wasnot available when I finished my year in Boston, but oneof Professor Sheehan’s postgraduate students subse-quently brought it over to Cambridge for me.

Armed with a reasonable supply of penicillamine,what I needed next was access to patients with Wilson’sdisease. Here I was lucky. My father, Sir Francis Walshe,was able to trace some patients via his neurologicalcolleagues: two from the National Hospital, QueenSquare, and one from the Whittington Hospital. All threeshowed an excellent response to their test dose of peni-cillamine.1 The two National Hospital patients were re-turned after the tests and put back on Dimercaprol,apparently I had failed to convince their physicians of thepotential value of the new medication. Fortunately forme, and I suspect for her, the patient from the Whitting-ton, referred by Dr. Michael Ashby, was allowed toremain for more extensive investigations and treatment.At that time, she was severely parkinsonian and hadfailed to improve on Dimercaprol (Fig. 5) so she was aprime case for a trial of a new therapy. As in the UnitedStates, there were in those days no ethical committeesand no drug safety laws to inhibit such a trial. I doubt thattoday such a trial would be permitted; such regulationsmay go some way to protecting patients, but they canalso stifle progress. As I had to prepare the penicillaminemyself from thiazolidine and pack it into capsules, thedose I was able to give Shirley was 450 mg a day, veryminimal. So progress was slow and it took almost a yearbefore it became obvious that the new therapy was ef-fective. Shirley subsequently married and brought upthree children. She has now been taking penicillaminefor 47 years, perhaps some 1.5 kg in all (Fig. 6); fewdrugs have to be administered for so long a time.

Figure 7 shows the first study with radioactive copper

FIG. 6. S.F. (now S.W.) 10 years after starting penicillamine, after thebirth of her third child.

FIG. 7. The first radioactive copper (64Cu) study showing the im-paired uptake of copper by the liver in a patient with Wilson’s disease.

856 J.M. WALSHE


demonstrating the impaired uptake of copper by the livercompared with that of a normal volunteer. After myprecious 50 g of penicillamine complex was depleted, Ifirst tried to synthesise it myself by the alkaline hydro-lysis of penicillin, which was at that time still a ratherprecious drug, but all I succeeded in doing was to pro-duce ropes of a sticky material that would have madeexcellent chewing gum apart from the flavour. Afterseveral failed attempts, I managed to interest The Dis-tillers Company Biochemicals, who were then the mainmanufacturers of penicillin by fermentation, in the pos-sibility of making penicillamine for me. Their medicaldirector, Dr. Kennedy, who came to see me in UniversityCollege Hospital London Medical School, was a severeasthmatic and by the time he had climbed four flights ofstairs to my laboratory he was so dyspnoeic and cya-nosed that I think I could have persuaded him to under-take almost any hair brained scheme I suggested! Nev-ertheless the meeting proved successful and thanks totheir Chief Chemist, Mr. Eaglesfield, my future suppliesof the drug were assured, fortunately as the safe D isomerand not the DL isomer prepared synthetically from va-line, the L isomer being potentially toxic.

A year after I left Boston, I had some really interestingresults to report and returning to the City Hospital for a

brief visit I described these at a Grand Round. Imaginemy surprise when I had finished speaking, to see Denny-Brown rise in his wrath and conduct what was clearly apredetermined demolition act, condemning my work andlauding the superior value of Dimercaprol. This came asa complete surprise as he had been so supportive of myinitial studies. It was, I believe, the result of the return ofUzman from military service to the Neurology Unit thatinduced this dramatic volte face.

It was interesting that Cumings,9,10 also in London,who originally suggested the use of Dimercaprol, wasequally critical of my work although eventually both ofthese authorities to some extent came round to my pointof view. Nevertheless, the Boston workers declined tocome to the first international Wilson’s disease meetingheld at the National Hospital for Neurology and Neuro-surgery in London, on the grounds that their work ondisturbances of peptide metabolism would not be ac-cepted as the orthodox view on the pathogenesis of thedisease. It was, I think, as a result of further studies onthe clinical efficacy of penicillamine that I was able topublish in 196011 and the publication of Scheinberg andSternlieb12 in New York, which led to a change of heart.

Some 10 years after the introduction of penicillamine,when I was working in the Department of Experimental

FIG. 8. Myself in the door of the wartime block that housed my laboratory in the Department of Experimental Medicine, Cannam’s Yard, Cambridge,in 1960.



Medicine in Cambridge (Fig. 8), its toxicity becameapparent. I had originally suggested that it might act as acysteine antimetabolite causing damage to the liver, skin,and hair. In fact, the main toxicities that have beenreported are immunologically induced, immune complexnephritis and the SLE syndrome, which is hard to pre-dict. It was the development of the nephrotic syndromein a boy who had been taking penicillamine for 10 yearsthat led to the search for an alternative chelating agent,work that led to the introduction of triethylene tetramine2HCl (Trientine)13 and later tetrathiomolybdate as effec-tive alternative treatments for patients with Wilson’sdisease. Figure 9 shows my new laboratory in the De-partment of Medicine where triethylene tetramine wasdeveloped, and Miss K. Gibbs who for several yearsmade all the supplies of this drug that were used in theUnited Kingdom before production was taken over by achemical manufacturer, K and K Grieff; but that is an-other story.

It is interesting that all the treatments in use presentlyhave been developed in academic departments: Petersteam in Oxford for BAL (Dimercaprol),14 Walshe inBoston for penicillamine,1 Schouwink in Arnhem forzinc sulphate,15 and Walshe again in Cambridge for

triethylene tetramine (Trientine)13 and tetrathiomolyb-date.16 It is a fact that no treatment for Wilson’s diseasehas been introduced by the giant multinational pharma-ceutical companies although after all the developmentalwork has been done and proved of value, they have beenhappy to market these drugs and, no doubt, make profitsacceptable to their shareholders as evidenced by thesharp rise in the cost of Dimercaprol in recent years.

REFERENCES

1. Walshe JM. Penicillamine, a new oral therapy for Wilson’s dis-ease. Am J Med 1956;21:487–495.

2. Abrahams EP, Chain E, Baker W, et al. Penicillamine, a charac-teristic degradation product of penicillin. Nature (Lond) 1943;7:151.

3. Wilson JE, Du Vigneaud V. Inhibition of the growth of the rat byL-penicillamine and its protection by aminoethanol and relatedcompounds. J Biol Chem 1950;63:184.

4. Vilensky JA, Robertson WA, Gilman S, Denny-Brown. Wilson’sdisease and BAL (British antilewisite [2,3-dimercaptopropano-lol]). Neurology 2002;59:914–916.

5. Uzman LL, Denny Brown. Amino aciduria in hepatolenticulardegeneration (Wilson’s disease). Am J Med Sci 1948;215:599–611.

6. Uzman LL, Hood B. The familial nature of the amino-aciduria ofWilson’s disease (hepatolenticular degeneration Am J Med Sci1952;223:392–400.

FIG. 9. Miss K. Gibbs, who prepared all the triethylene tetramine 2HCl used in the proving period of this drug, in my new laboratory in the ColdTemperature Research Building, Downing Street, Cambridge, in the late 1960 and early 1970s.

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7. Asatoor AM, Milne MD, Walshe JM. The effect of chelationtherapy on the amino aciduria and peptiduria of Wilson’s disease.J Roy Col Physicians 1983;17:122–125.

8. Cartwright GE, Hodges RE, Gubler CJ, et al. Studies on coppermetabolism XIII, hepatolenticular degeneration. J Clin Invst 1954;33:1487–1501.

9. Cumings JN. The copper and iron content of brain and liver inhepatolenticular degeneration. Brain 1948;71:410–415.

10. Cumings JN. The effect of BAL in hepatolenticular degeneration.Brain 1951;74:10–22.

11. Walshe JM. The treatment of Wilson’s disease with penicillamine.Lancet 1960;1:188–192.

12. Scheinberg IH, Sternlieb I. Long-term management of hepatolen-ticular degeneration (Wilson’s disease). Am J Med 1960;29:316–333.

13. Walshe JM. The management of penicillamine nephropathy inWilson’s disease, a new chelating agent. Lancet 1969;1:1401–1402.

14. Peters RA, Stocken LA, Thompson RHS. British antilewisite(BAL). Nature (Lond) 1954;15:656.

15. Schouwink G. De hepato-cerebrale degeneratie. Arnhem: Van derWiel; 1961.

16. Walshe JM. Copper: its role in the pathogensis of liver disease.Semin Liver Dis 1984;4:252–263.



the story of penicillamine: a difficult birth

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