Diflunisal ('Dolobid') once-a-day in the treatment of rheumatoid arthritis.

A 4-week, double-blind, controlled multi-centre study was carried out in 235 patients with active rheumatoid arthritis to compare the efficacy and tolerance of 500 mg or 1000 mg diflunisal per day administered once daily, in the evening, or in divided, twice daily dosage. The results showed that diflunisal given once daily was at least as effective as diflunisal given twice daily. Day pain, morning stiffness, average grip strength and erythrocyte sedimentation rate improved similarly in both groups. Significant differences favouring the once-daily regimen were observed for improvement in night pain, Ritchie index and overall assessments by patient and investigator. Adverse experiences were slightly more common in patients taking diflunisal once daily (24% vs 19%) but this difference was not significant. It is concluded, therefore, that diflunisal once-a-day is an alternative regimen for the treatment of rheumatoid arthritis. It is at least as effective as the twice-daily regimen and may provide additional convenience to the patient and potential enhancement of compliance.