A Comparison of Benorylate and Aspirin in the Treatment of Rheumatoid Arthritis

Abstract

A Double-Blind double-dummy cross-over comparison was made of 4.8 g. aspirin with 8.0 g. benorylate daily, using in-patients with active rheumatoid arthritis. Compared with an initial period on paracetamol, the results showed both preparations to be equi-potent, causing significant decrease in pain score (p<0.001) and morning stiffness (p<0.001). The plateau plasma salicylate levels during aspirin therapy were significantly higher (p<0.001) than those during benorylate therapy. This was reflected in a much higher incidence of salicylism during aspirin therapy. In view of the equivalent therapeutic effect of benorylate despite the lower plasma salicylate levels, it is suggested that the parent compound, its N.A.P.A. metabolites, or both may contribute to its clinical effect. Benorylate (4-acetamidophenyl 2-acetoxybenzoate) is a lipid soluble ester of acetylsalicylic acid and N-acetyl p-aminophenol (N.A.P.A.) which has been shown to be useful in the treatment of the rheumatic diseases. The present study was designed to compare the efficacy of benorylate with an equivalent dose of aspirin under strictly controlled conditions in patients with active rheumatoid arthritis.