[Therapy of rheumatoid arthritis with azathioprine--results of an open long-term study of at least 4 years with 528 patients].

In an open study 528 patients affected with rheumatoid-arthritis were treated with azathioprine, then observed for a period of at least 4 years and assessed according to Steinbrocker's therapeutic criteria. In 178 of them (33.7%) the therapy was still effective even after that time, which corresponds to grade I and II according to Steinbrocker. The therapy was cancelled in 211 patients due to ineffectiveness and in 85 patients due to side-effects. The side-effects are represented in detail. Owing to the favorable relationship between benefit and risk, azathioprine proves to be a means of first choice in all cases with a high process activity and an unfavorable prognosis.