Mesalamine once daily is more effective than twice daily in patients with quiescent ulcerative colitis

Oral mesalamine (5-aminosalicylate) is the current standard of care for mild-to-moderate ulcerative colitis. We investigated the efficacy and safety of once daily administration of prolonged-release mesalamine granules in maintenance of remission in patients with quiescent ulcerative colitis, compared with the well established twice daily dosing regimen.

In this multicenter, randomized, single blind, noninferiority trial, 362 patients with quiescent ulcerative colitis were randomly assigned (1:1) to groups that were given oral mesalamine 2 g, once daily, or 1 g, twice daily, for 12 months. The primary objective was to compare remission rates at 1 year, based on the ulcerative colitis disease activity index score, using Kaplan-Meier methodology.

At 1 year, 70.9% of the group given 2 g mesalamine once daily remained in remission vs 58.9% of the group given 1 g mesalamine twice daily; this difference was statistically significant (P = .024), indicating the increased efficacy of once daily, compared with twice daily, dosing. Self-reported adherence to therapy, measured by visual analog scale score after 4, 8, and 12 months, was significantly greater in the group given 2 g mesalamine once daily, compared with twice daily, at all but 1 study visit (P < .05). Compliance measured by medication taken was not significantly different between the groups. The difference between the 2 groups in overall incidence of adverse events was not statistically significant (P = .23).

Patients with ulcerative colitis given prolonged-release oral mesalamine 2 g once daily had better remission rates, acceptability, and self-reported adherence to therapy compared with patients given oral mesalamine 1 g twice daily.