Controlled multicenter trial of tiopronin and d-penicillamine for rheumatoid arthritis

Fifty-seven patients took part in a controlled double-blind trial between tiopronin and D-penicillamine as basic treatment for rheumatoid arthritis. Thirty-nine (19 receiving tiopronin, 20 receiving D-penicillamine) completed the trial after 1 year. Both drugs resulted in a decrease of the erythrocyte sedimentation rate, Ritchie index, and Lee index and in a sparing effect on symptomatic antiinflammatory therapy. Improvement in these variables was statistically highly significant at any interval with tiopronin, but was sometimes less or not at all significant with D-penicillamine. Nevertheless, the difference in effects between the 2 drugs never reached statistical significance. Six patients receiving tiopronin and 6 receiving D-penicillamine were taken out of the experiment because of side effects.