Penicillamine in rheumatoid arthritis: adverse effects.

The use of penicillamine in rheumatoid arthritis (RA) is limited by the incidence of adverse effects, some of which are potentially hazardous. However, adverse effects are dose-related and the advantages and disadvantages of different fixed and flexible dose regimes are discussed. The incidence of adverse effects is significantly greater in patients previously treated with gold who developed toxicity to that drug--no such increase being found in gold treated patients whose only reason for stopping gold was ineffectiveness. Rashes which develop after several months of treatment are variants of pemphigus and their various presentations are described. Fatal reactions, fortunately rare, are predominantly associated with aplasia of the bone marrow. Monthly haematological checks coupled with meticulous charting of the results may reveal trends as well as numerical changes and serve as an early warning of marrow damage.