Naproxen and aspirin in rheumatoid arthritis: a multicenter double-blind crossover comparison study.

One hundred nineteen adults with active definite or classical rheumatoid arthritis were studied in a multicenter double-blind crossover study of naproxen (500 mg/day) and aspirin (3.6 Gm/day). Each drug was given in sequence for a six-week study period. Patients already receiving corticosteriod and/or gold therapy were maintained at constant dose throughout the study, but analgesics and other nonsteroidal antiinflammatory agents were discontinued at baseline. Objective and subjective evaluations by both investigator and patient were carried out at two-week intervals. No significant difference in global evaluation of efficacy or individual measures of efficacy was observed between aspirin and naproxen therapy, although physicians' global evaluation tended to favor naproxen. Sedimentation rate was lower on aspirin (naproxen 43.1 mm/hr; aspirin 38.7 mm/hr; P=0.02). Naproxen, 250 mg twice daily, was significantly better tolerated than aspirin, 900 mg four times daily. Mild, moderate, and severe side effects were less frequent with naproxen. The incidence of heartburn was significantly lower on naproxen, and significantly fewer patients terminated their six-week study period on naproxen than on aspirin. There were no significant deviations from baseline values in hematocrit, white cell or differential counts, or in tests of renal and hepatic function during the course of the study.