Update on the role of modified release mesalamine in the management of ulcerative colitis and Crohn’s disease

5-aminosalicyclates (5-ASA) remain a key first-line therapy for patients with ulcerative colitis (UC). A range of 5-ASA preparations is available and Eudragit-S(®) coated modified release formulations of mesalamine, such as Asacol(®), remain among the most popular choices. We here review the current understanding of the mechanism of action of 5-ASA in inflammatory bowel disease. We evaluate evidence supporting the efficacy and safety of modified release mesalamine for both induction and remission maintenance in UC, including a review of the data from the recent ASCEND studies. We also examine the controversial issue of the role of mesalamine in treatment of Crohn's disease (CD) and highlight data supporting its use following surgically induced remission of CD. Evidence supporting the use of mesalamine as prophylaxis for colorectal cancer and dysplasia will be considered. Finally, recent developments in our understanding of how to use modified release mesalamine in a safe and cost-effective manner are evaluated, including discussion of the importance of studying patient non-adherence as a key component of future studies in this area.