The role of aminosalicylates at the beginning of the new millennium in the treatment of chronic inflammatory bowel disease

Objective: To discuss the pharmacological properties of aminosalicylates and their potential value in the treatment of chronic inflammatory bowel disease (IBD). Methods: A review of clinical studies on the pharmacokinetics and mode of action of aminosalicylates is provided. In addition, the clinical efficacy and safety of aminosalicylates in the treatment of IBD, according to several recent meta-analyses, is summarised. Results: Whereas aminosalicylates represent drugs of first choice in the acute treatment of ulcerative colitis and also for maintaining those patients in remission, their value for patients with Crohn's disease, either for achieving or maintaining remission, is at best modest. There is a large variability in the clinical results, especially in Crohn's disease, which is probably due to the variable extent and severity of IBD, different instruments in the evaluation of therapeutic outcome, and also at least partly caused by the different preparations and dosages of aminosalicylates used, as well as the high variation in drug disposition and topical availability of the active drug. The popular use of aminosalicylates is most likely due to the low incidence of side effects and the good overall safety records of mesalazine (mesalamine). Conclusions: Apparently, the full therapeutic potential of aminosalicylates has not yet been evaluated (e.g. upper dosage range, combination therapy, responding subgroups). Consequently, the imperfect treatment might be improved in the new millennium by novel insights in the complex mode of action of mesalazine as well as in the etiopathogenesis of IBD.