Abstract

In patients with ulcerative colitis mesalazine (Asacol) is an effective and often better tolerated alternative for sulphasalazine. Unlike sulphasalazine, however, the drug is not effective in rheumatoid arthritis. The discovery that mesalazine helps in ulcerative colitis raised the possibility that the 5-aminosalicylate part of the sulphasalazine molecule might explain its activity in rheumatoid arthritis.¹ Two controlled studies have shown that it does not: the activity resides either in the sulphasalazine molecule as a whole, or in the sulphapyridine moiety.^2,3