Long-term efficacy and safety of azathioprine in ulcerative colitis.

BACKGROUND AND AIMS

Azathioprine (AZA) is an established treatment for ulcerative colitis (UC).However, controversy exists regarding its efficacy in inducing and maintaining clinical remission, and long-term data are lacking. We studied the effectiveness of AZA in a large cohort of UC patients treated in a single center.

METHODS

All UC patients treated with AZA were identified from a prospective electronic database. We assessed response to therapy at 4 months and sustained clinical benefit at the last point of follow-up. We also examined predictors of response and sustained clinical benefit, as well as outcomes in those treated with AZA for >5 years.

RESULTS

The study included 255 patients. At 4 months, 207 (81.2%) of 255 patients were still on AZA and 163 (63.9%) had responded to therapy. At the last point of follow-up 164 (64.3%) patients were still receiving AZA, of whom 154 (60.4%) achieved sustained clinical benefit. This effect was durable among 71 patients who received AZA for >5 years, with 61 (85.9%) considered to have achieved sustained clinical benefit. Twenty-six patients required admission to hospital for an exacerbation during AZA treatment, 20 patients ultimately required biologic therapy, and 21 underwent colectomy. Only two (2.8%) of 71 patients receiving AZA for >5 years needed to escalate to a biologic therapy, and only one (1.4%) required a colectomy.

CONCLUSIONS

AZA is a safe and effective therapy in UC patients who fail 5-aminosalisylates in both the short and long term. Escalation to a biologic therapy or colectomy was unlikely among patients who were able to continue AZA therapy beyond 5 years.