Update on mesalazine for inflammatory bowel disease

The role for mesalazine in inflammatory bowel disease has become increasingly apparent although there remain several areas that need further clarification. In ulcerative colitis (UC) oral mesalazine is a proven first-line therapy for mild-to-moderate disease and the primary maintenance approach in Europe and North America. Rectally administered mesalazine is the most effective and least noxious treatment for distal UC. There is a dose response that is somewhat higher than anticipated compared to salazopyrine for oral mesalazine in active UC and, compared to salazopyrine, the optimal maintenance dose jot oral mesalazine is identical to the dose used to induce remissions in individual patients. There does not appear to be a dose-response above 1 g/day for rectally administered mesalazine. Whereas the volume of administration may impact on the proximal spread and efficiency. Patients who require rectal mesalazine will also respond best to continuation of topical therapy although transitioning to oral therapy may be preferable for compliance and quality-of-life. There are more controversies regarding the role of mesalazine in Crohn's disease (CD). The data on oral mesalazine are consistent, suggesting efficacy (induction of remission) in approximately 40% of patients with mild-to-moderate disease. The variable placebo-response necessitates adequate numbers of patients to reproduce statistical advantages. The heterogeneity of "maintenance" indications in CD requires careful scrutiny of the trials with mesalazine. Summarising the data, it appears that mesalazine will be most effective at preventing relapse for patients who have responded to mesalazine induction, have not required steroids to induce remission, and for non-smokers. Mesalazine also has been consistently effective at preventing relapse after surgical resections, Primarily proximal to ileocolonic anastomoses. A primary benefit of mesalazine in active and maintenance therapy has been the large margin of safety and the scarcity of short- or long-term side-effects at oral doses zip to 5 g/day and in combination of oral and topical doses up to 8 g/day.