Factors affecting the development of penicillamine side-effects.

Characteristics of patients on penicillamine therapy for rheumatoid arthritis were correlated with the occurrence of different side-effects. Patients developing proteinuria tended to have lower sheep-cell agglutination test titres prior to therapy, but no other correlations were found. It is postulated that rheumatoid factor reacts with immune complexes, causing their precipitation and reducing renal glomerular deposition and therefore the incidence of proteinuria. Penicillamine would surely be the first choice of anti-rheumatic therapy if it were not for its side-effects. It is capable of controlling the disease, but in many cases treatment must be interrupted because of some potentially serious side-effects, such as thrombocytopenia, rash or nephropathy. Understanding the mode of action of a drug may lead to the development of new and better compounds. Similarly, understanding the mechanism of the side-effects may lead to their elimination. This survey was designed to identify factors which influenced the development of particular side-effects in patients receiving penicillamine for rheumatoid arthritis.