A double-blind, comparative study of diflunisal and naproxen in the treatment of rheumatoid arthritis.

A randomized, double-blind trial was carried out in 47 hospital out-patients, with classical rheumatoid arthritis, to compare the efficacy and tolerance of diflunisal with that of naproxen. After an initial one week washout period the patients received diflunisal 1000 mg daily or naproxen 750 mg daily using a double placebo, crossover method. Each drug was administered for a three week period separated by a one week between treatment washout. With both drugs there was an improvement in objective and subjective assessments of response indicating that they each had an effective anti-inflammatory action. Diflunisal produced a significantly greater improvement in evening pain (p = 0.03), morning stiffness (p = 0.01) and the average total grip strength (p = 0.05). Nearly 60% of patients preferred diflunisal to naproxen but this was not of statistical significance. Frequency and severity of side-effects were similar. The similarity of diflunisal to aspirin in urate lowering is commented upon.