Penicillamine-induced myasthenia gravis associated with antibodies to acetylcholine receptor.

A woman with rheumatoid arthritis was treated with penicillamine and developed myasthenia gravis. This drug-induced disease was associated with characteristic autoantibodies to acetycholine receptor. After discontinuing the drug, her symptoms improved and the antibody titers fell. Penicillamine is now being used much more frequently in the treatment of rheumatoid arthritis and it is likely that this complication will become more prevalent.