D-penicillamine withdrawal in rheumatoid arthritis.

Thirty-eight patients with rheumatoid arthritis in remission on penicillamine were entered into a prospective, randomised, placebo controlled study to determine the effects of gradual penicillamine withdrawal, to find a serological marker capable of predicting relapse, and to assess the effects of reintroduction of penicillamine. 80% of patients attempting gradual penicillamine withdrawal flared. There was no single serological marker capable of predicting outcome consistently. Decreasing SH levels were highly specific for recurrence of active synovitis but were insensitive. Reintroduction of penicillamine was successful. The implications of these findings, particularly concerning duration of therapy with disease modifying drugs, are discussed.