Reappraisal of the use of methotrexate in rheumatic disease.

Methotrexate has been available for clinical use since 1951. Initially, it was utilized as a chemotherapeutic agent, but it has since been widely used in the treatment of such nonmalignant disorders as psoriasis and, more recently, experimentally in psoriatic arthritis and polymyositis. Its mechanism of action is imprecisely understood but it appears to involve both anti-inflammatory and immunosuppressive effects. Controlled pilot studies are underway using methotrexate in patients with severe rheumatoid arthritis.