Ibuprofen is a nonsteroidal drug with analgesic, antipyretic, and anti-inflammatory properties that was recently introduced for use in antiarthritis therapy in the United States. In a year-long double-blind multiclinic trial in 885 patients with rheumatoid arthritis, ibuprofen was at least as satisfactory as aspirin, considering both efficacy and tolerance. In the majority of patients, daily doses ranged from 800 to 1,600 mg of ibuprofen and 3 to 6 gm of aspirin. The drugs did not differ greatly in providing relief from arthritis symptoms, but ibuprofen was definitely better tolerated, especially in regard to gastrointestinal complaints. Seven percent of the ibuprofen group dropped out of the study because of adverse reactions, as compared with 16% of the aspirin group; 17% of the ibuprofen group and 31% of the aspirin group had gastrointestinal symptoms.