Clinical Medicine Insights: Gastroenterology

Medical management of ulcerative colitis has continued to evolve over more than half of a century. Perhaps, the important advance was the development of sulfasalazine, a drug initially used for the treatment of inflammatory joint disease and only later in the treatment of inflammatory bowel disease. Sulfasalazine was a combination designer drug consisting of sulfapyridine, a sulfa-containing antibacterial agent, and 5-amino-salicylate (5-ASA), an anti-inflammatory agent. Its value appeared to be its ability to target a therapeutic concentration of the 5-ASA component of the medication primarily in the colon, largely avoiding proximal small intestinal absorption. With increasing experience, however, it also became evident that many patients treated with sulfasalazine developed intolerance to the drug and, in some rare instances, serious drug-induced hypersensitivity reactions, largely to the sulfapyridine portion. As a result, a number of alternative forms of delivery of 5-ASA were developed consisting of either a similar sulfasalazine-like prodrug formulation requiring luminal destruction of an azo-bond releasing the 5-ASA or a pH-dependent 5-ASA packaging system that permitted release in the distal intestine, particularly in the colon. As a result, 5-ASA—containing medications continue to provide a valuable management tool for remission induction in mildly to moderately active distal or extensive ulcerative colitis, an additional option for more severely symptomatic disease and value for maintenance therapy with limited potential side effects, even with long-term use.