BACKGROUND: High-dose (4.0 g/day) mesalazine is typically used for induction therapy, but its efficacy as maintenance therapy remains to be determined. We conducted a multicenter retrospective study to investigate the efficacy of continuous treatment with 4.0 g/day of mesalazine.

MATERIAL AND METHODS: Japanese ulcerative colitis (UC) patients receiving acute induction therapy with 4.0 g/day mesalazine were enrolled and followed. Those who clinically improved or who achieved clinical remission were categorized into 2 sub-groups according to the median duration of treatment with 4.0 g/day of mesalazine. The clinical relapse frequency and the time to relapse were analyzed.

RESULTS: We enrolled 180 patients with active UC, and then 115 patients who clinically improved or who achieved clinical remission after treatment with 4.0 g/day mesalazine were categorized into 2 sub-groups according to the median of treatment duration: a short-term treatment group (≤105 days, n=58) and a long-term treatment group (>105 days, n=57). Overall, 45 (39.1%) patients relapsed: 28 (48.3%) in the short-term treatment group and 17 (29.8%) in the long-term treatment group. This difference was statistically significant (p<0.05). The relapse-free rate in the long-term treatment group was significantly higher than that in the short-term treatment group (p<0.05). The mean time to relapse in the long-term treatment group was significantly longer than that in the short-term treatment group (425.6±243.8 days vs. 277.4±224.5 days; p<0.05).

CONCLUSIONS: Long-term continuous treatment with high-dose mesalazine (4.0 g/day) may be more effective than short-term treatment for maintenance of remission in UC patients.

Keywords: Colitis, Ulcerative - prevention & control, Cohort Studies, Dose-Response Relationship, Drug, Japan, Maintenance Chemotherapy - statistics & numerical data, Mesalamine - therapeutic use, Recurrence