Mesalamine delivery systems: do they really make much difference?

Sulfasalazine's role as the first-line of therapy in patients with inflammatory bowel disease has led to the development of other "designer" aminosalicylates, which eliminate the sulfa-moiety, and attempt to target the topically active mesalamine to the inflamed bowel. Olsalazine sodium and balsalazide disodium utilize the same azo-bond structure as sulfasalazine, requiring release of active mesalamine by colonic bacteria, and thus targeting these agents to the colon. Other mesalamine delivery systems use pH-dependant- or moisture-release to liberate the active mesalamine in both the large and small bowel. Direct application of mesalamine via enema or suppository is also effective in patients with distal colitis. The pharmacology and thus the undesirable drug absorption rates differ between drugs, although the clinical importance of these characteristics is debatable. Differences in release-systems, the impact of the fed and fasting state, and unique patient intolerances to individual agents demand an understanding of each of these products, and their application to patient therapy. (C) 2004 Elsevier B.V. All rights reserved.