Methotrexate therapy in polymyositis

5 of 16 patients with polymyositis, whose disease could not be controlled with corticosteroids alone, received Methotrexate therapy. 4 had pure polymyositis while one had myositis associated with systemic sclerosis. As a group, they demonstrated, clinically and chemically, more severe muscle disease than those requiring steroids alone. 3 patients clearly responded to the drug, but toxicity was a significant limiting factor. The most serious complication, namely Methotrexate pneumonitis, observed in two patients receiving oral dosage, contributed to death in one. Methotrexate therapy, while a useful adjunct in the steroid refractory patient, is highly toxic, especially when given orally, and must be used with caution.