[Leflunomide--the first specific disease-modifying drug against rheumatoid arthritis].

Rheumatoid arthritis (RA) is a disabling disorder with chronic inflammation leading to significant disability and pain if not treated early and effectively. Leflunomide is the first drug developed and registered specifically for modifying disease course in RA, and is a good complement to other forms of drug therapy currently in use. In clinical trials, leflunomide has been proven to exert an effect on clinical parameters of RA-inflammation superior to placebo and equal to methotrexate and sulphasalazine, while clinical response evidently begins somewhat earlier than on these other drugs. There appears to be a retarding effect on radiographic progression over 13 months comparable to that of methotrexate and sulphasalazine. The very long elimination half-life as well as side effects including nausea, diarrhea, and elevated liver enzymes (almost as frequent as with methotrexate) hamper its usefulness, and its definitive place in modern RA-therapy remains to be established.