Newer 5-aminosalicylic acid based drugs in chronic inflammatory bowel disease.

Since the discovery that 5-aminosalicylic acid (5-ASA) is the active moiety of sulphasalazine in the treatment of chronic inflammatory bowel disease, several new 5-ASA based drugs have been developed. These consist either of slow- or delayed-release formulations of plain 5-ASA or sulpha-free azo compounds of 5-ASA. The different formulations and compounds have varying bioavailabilities, which makes it possible to use them alternatively in different clinical situations. A review of the literature is given, together with suggestions as to how the new drugs might be used in different clinical situations.