Diflunisal: six-month experience in osteoarthritis.

The analgesic efficacy and tolerance of diflunisal in patients with osteoarthritis has been compared with ibuprofen and acetylsalicylic acid (ASA) in two clinical studies carried out double-blind for 12 weeks and then continued single-blind for a further 12 weeks. The studies involved 115 patients and 695 patients, respectively. Diflunisal was superior to ibuprofen in overall response, as assessed by both patients and investigators ( < 0.01), improvement in disease activity and by improvement in internal rotation of the hip ( < 0.05). Diflunisal was superior to ASA in overall response, as assessed by both patients and investigators, therapeutic index ( < 0.01), reduction in morning stiffness, and by improvement in performance of daily activities ( < 0.05). In the first study, the mean daily dose of diflunisal during the double-blind period was 702 mg and of ibuprofen 1 161 mg. In the second study, the mean daily dose of diflunisal was 612 mg and of ASA 2 461 mg. Diflunisal produced fewer gastrointestinal side-effects after 24 weeks of therapy than did ibuprofen ( < 0.01). Diflunisal produced fewer general side-effects and fewer gastrointestinal side-effects during the double-blind and the single-blind phases of the study ( < 0.01). Fewer patients discontinued therapy because of side-effects in the diflunisal group than in the ASA group ( < 0.05). Both ASA and diflunisal decreased serum uric acid, with diflunisal being more uricosuric than aspirin ( < 0.01).