Diflunisal: six-month experience in osteoarthritis.

1 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. 2 Diflunisal was superior to ibuprofen in overall response, as assessed by both patients and investigators (P < 0.01), improvement in disease activity and by improvement in internal rotation of the hip (P < 0.05). 3 Diflunisal was superior to ASA in overall response, as assessed by both patients and investigators, therapeutic index (P < 0.01), reduction in morning stiffness, and by improvement in performance of daily activities (P < 0.05). 4 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. 5 Diflunisal produced fewer gastrointestinal side-effects after 24 weeks of therapy than did ibuprofen (P < 0.01). 6 Diflunisal produced fewer general side-effects and fewer gastrointestinal side-effects during the double-blind and the single-blind phases of the study (P < 0.01). Fewer patients discontinued therapy because of side-effects in the diflunisal group than in the ASA group (P < 0.05). 7 Both ASA and diflunisal decreased serum uric acid, with diflunisal being more uricosuric than aspirin (P < 0.01).