Captopril: a new treatment for rheumatoid arthritis?

Captopril, an inhibitor of angiotensin converting enzyme, is prescribed for hypertension. Its molecular structure shares features with D-penicillamine, in that both agents contain a thiol group. In addition, captopril has immunosuppressant activity. Captopril was therefore considered a potential slow-acting drug for treating rheumatoid arthritis. In an open study 15 patients with active arthritis were treated with captopril and followed for 48 weeks. Two-thirds of the patients reported improved arthritis symptoms, and significant changes were seen in several clinical and biochemical measurements, notably Ritchie articular index, clinical score, plasma viscosity, and C-reactive protein. Side-effects were generally mild and included transient taste loss, rashes, and hypotension. Only 2 patients withdrew as a result of drug intolerance.