Meta-analysis: the efficacy of azathioprine and mercaptopurine in ulcerative colitis
Article first published online: 15 APR 2009
© 2009 Blackwell Publishing Ltd
Alimentary Pharmacology & Therapeutics
Volume 30, Issue 2, pages 126–137, July 2009
How to Cite
GISBERT, J. P., LINARES, P. M., MCNICHOLL, A. G., MATÉ, J. and GOMOLLÓN, F. (2009), Meta-analysis: the efficacy of azathioprine and mercaptopurine in ulcerative colitis. Alimentary Pharmacology & Therapeutics, 30: 126–137. doi: 10.1111/j.1365-2036.2009.04023.x
- Issue published online: 26 JUN 2009
- Article first published online: 15 APR 2009
- Publication data Submitted 13 February 2009 First decision 10 March 2009 Resubmitted 13 April 2009 Accepted 14 April 2009 Epub Accepted Article 15 April 2009
Background Debate exists regarding to whether thiopurine therapy is as effective in ulcerative colitis (UC) as it is in Crohn's disease.
Aim To review systematically the efficacy of azathioprine (AZA) and mercaptopurine (MP) in UC, and to conduct a meta-analysis of randomized clinical trials evaluating the efficacy of AZA/MP for the induction or maintenance of UC 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 with placebo/5-aminosalicylates were included in the meta-analysis. Search strategy: Electronic and manual. Study quality: Independently assessed by two reviewers. Data synthesis: By ‘intention-to-treat’.
Results Thirty noncontrolled studies (1632 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. (i) 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). (ii) 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 an NNT of 5 and an absolute risk reduction of 23%.