Meta-analysis: efficacy of azathioprine and mercaptopurine in ulcerative colitis.Gisbert JP, Linares PM, McNicholl AG, Maté J, Gomollón F. Aliment Pharmacol Ther. 2009 Apr 16. [Epub ahead of print]
SUMMARY OBJECTIVE: 1) To systematically review the efficacy of azathioprine(AZA) and mercaptopurine(MP) in ulcerative colitis(UC); and 2) to conduct a meta-analysis of randomized clinical trials evaluating the efficacy of AZA/MP for the induction or maintenance of UC’s clinical remission.
METHODS: Selection of studies: evaluating AZA/MP for induction and/or maintenance of clinical remission of UC. Randomized-controlled-trials comparing AZA/MP vs. placebo/5-aminosalicylates were included in the meta-analysis. Search strategy: electronic&manual. Study quality: independently assessed by two reviewers. Data synthesis: by “intention-to-treat”. RESULTS: Thirty non-controlled studies(1,632 patients) were included in the systematic review. Mean efficacy of AZA/MP was 65% for induction, and 76% for maintenance of the remission. Seven controlled studies were included in the meta-analysis. 1)Induction of remission: Four studies(89 AZA/MP-treated patients) showed mean efficacy of 73% vs. 64% in controls(OR=1.59;95%CI=0.59-4.29). 2)Maintenance of remission: Six studies(124 AZA/MP-treated patients) showed mean efficacy of 60% vs. 37% in controls(OR=2.56; 95%CI=1.51-4.34). When only studies comparing AZA/MP vs. placebo were considered, OR was 2.59(95%CI=1.26-5.3), absolute risk reduction was 23%, and number-needed-to-treat(NNT) to prevent one recurrence was 5. CONCLUSION: Thiopurine drugs (AZA/MP) are more effective than placebo for the prevention of relapse in UC, with a NNT of 5 and an absolute risk reduction of 23%.