The medical records of our first 200 consecutive rheumatoid arthritis patients treated with penicillamine were analyzed retrospectively. All but 5 patients (97.5%) had undergone earlier chrysotherapy that resulted in either therapeutic failure or toxicity. Only 57 patients (28.5 %) were still receiving penicillamine on January I, 1981, and the duration of therapy ranged from 23 to 62 months. The dropout rate due to toxicity, therapeutic failure, relapse, or other reasons was very high (71.5%). Toxic effects required permanent discontinuance in 56 patients (28%). Therapy was discontinued for 36 patients (18%) because of no benefit. A striking number (20) had relapse after therapeutic success and while continuing to take penicillamine, and the therapy had to be discontinued, a relapse rate of 10%. Therapy for the remaining 15.5% was discontinued for miscellaneous reasons that were not related to penicillamine per se: patient anxiety (6%), lost to followup (5%), hospitalization for reasons unrelated to penicillamine therapy (2%), lack of cooperation and study protocol (1% each), or pregnancy (0.5%). By our criteria, 142Norman 0. Rothermich, MD: Clinical Professor of Medicine,