The long-term efficacy of azathioprine in steroid-dependent ulcerative colitis

OBJECTIVE. The long-term efficacy of azathioprine (AZA) in steroid-dependent ulcerative colitis (UC) is still unclear. We aimed to evaluate the efficacy of AZA in patients with steroid-dependent UC. MATERIAL AND METHODS. We retrospectively reviewed the medical records of 106 patients with steroid-dependent UC who were administered AZA. Three-year outcomes of AZA therapy were evaluated. The outcome of the treatment was defined as (1) success, indicating induction and maintenance of remission throughout the study period (complete success) or remission followed by infrequent and short relapses (partial success); or (2) failure, indicating the absence of remission, frequent or prolonged relapses, infliximab administration, or colectomy. RESULTS. Of the 106 patients, 73 (68.9%) continued on AZA for >6 months (AZA therapy group) and 33 (31.1%) discontinued AZA within 6 months due to intolerance (AZA intolerance group, n = 20), colectomy (n = 6), or follow-up loss (n = 7). Three-year outcomes for 106 patients were success in 54.7% (complete success, 35.8%; partial success, 18.9%), failure in 32.1% (frequent or prolonged relapses, 12.3%; infliximab administration, 5.6%; colectomy, 14.2%), and follow-up loss or death in 13.2%. The success rate increased to 71.2% (complete success, 46.6%; partial success, 24.7%) when the analysis was confined to the 73 patients who continued AZA for > 6 months. The 3-year success rate was higher in the AZA therapy group (71.2%) than the AZA intolerance group (25.0%) (p < 0.001). CONCLUSIONS. AZA is an effective treatment for steroid-dependent UC. The efficacy of AZA is well sustained over 3 years.