A comparative study of isoxicam and naproxen in rheumatoid arthritis.

A 4-week parallel-group, double-blind comparison of isoxicam 200 mg once daily and naproxen 250 mg 3 times daily was carried out on 30 patients with classic or definite rheumatoid arthritis. Fifteen patients were randomly assigned to each treatment group. The articular index, scoring on a pain scale and morning stiffness were significantly reduced after 2 and 4 weeks of treatment with both drugs. Grip strength was significantly increased after 4 weeks of naproxen treatment. The mean increase in grip strength was also comparable in isoxicam-treated patients, but did not reach statistical significance. Joint swelling and walking times showed improvement in both groups. One patient withdrew from isoxicam treatment with a pruritic rash considered to be drug-related and another stopped taking isoxicam because of dizziness, nausea and vomiting--also probably drug-related. Eight other patients, 4 treated with isoxicam and 4 with naproxen, reported adverse reactions associated with the digestive system. In this study isoxicam 200 mg taken once daily was similar in efficacy to and was associated with a similar incidence of adverse reactions as naproxen 250 mg taken 3 times daily. Both drugs were effective in the treatment of rheumatoid arthritis and were well tolerated.