Abstract

Four drugs based on 5-aminosalicylic acid (5-ASA) are now available for the treatment of ulcerative colitis. Salazopyrin (sulphasalazine) is a chemical combination of 5-ASA plus sulphapyridine, and Dipentum (olsalazine) a chemical combination of two molecules of 5-ASA. Asacol (mesalazine e.c.) is 5-ASA alone but in an enteric-coated, delayed-release formulation and Pentasa (mesalazine s.r.) 5-ASA in a slow-release formulation. In this article we look at the pharmacokinetic properties of these alternatives and discuss how they influence choice.