Kavinderjit Nanda, Alan C MossCenter for Inflammatory Bowel Disease, BIDMC/Harvard Medical School, Boston, MA, USAAbstract: Ulcerative colitis (UC) is a chronic inflammatory disease of the colon that typically manifests as diarrhea, abdominal pain, and bloody stool. Complications, such as colorectal cancer and extraintestinal manifestations, may also develop. The goals of management are to induce and maintain clinical remission and to screen for complications of this disease. Mesalamine is a 5-aminosalicylic acid compound that is the first-line therapy to induce and maintain clinical remission in patients with mild-to-moderate UC. For patients who are refractory to mesalamine or have more severe disease, steroids, azathioprine/mercaptopurine, cyclosporine, or infliximab may be used, induce and/or maintain remission. The various formulations of mesalamine available are primarily differentiated by the methods of delivery of the active compound of the drug to the colon. Mesalamine with Multi-Matrix System® (MMX) technology (Cosmo SpA, Milan, Italy) is an oral (1.2 g), once-daily tablet formulation of mesalamine used for the treatment of UC (Lialda® or Mezavant®, Shire Pharmaceuticals Inc, Wayne, PA). In clinical studies, MMX mesalamine (taken as a once-daily dose of 2.4 or 4.8 g) effectively induced and maintained clinical remission in patients with active mild-to-moderate UC. The overall safety profile of MMX mesalamine is similar to other oral mesalamine formulations. The use of such once-daily formulations has led to intense interest in whether simplified pill regimens can improve patient adherence to mesalamine therapy.Keywords: mesalamine, 5-ASA, ulcerative colitis, inflammatory bowel disease