title: Exposing the weaknesses: a systematic review of azathioprine efficacy in ulcerative colitis.
abstract: BACKGROUND
  Published trials evaluating the efficacy of 6-thioguanine anti-metabolites in the treatment of ulcerative colitis (UC) have yielded conflicting results. We performed a systematic review and meta-analysis to evaluate the clinical efficacy of 6-thioguanine anti-metabolites for the maintenance of clinical remission after standard induction with corticosteroids.
  
  
  METHODS
  A comprehensive search of online databases was conducted. Only randomized controlled trials with 6-thioguanine antimetabolites within a minimum duration of follow-up of 6 months were selected.
  
  
  RESULTS
  Five trials were included in the meta-analysis. The pooled relative risk estimate for "success of treatment" with azathioprine (AZA) compared to 5-aminosalicylic acid or placebo was 1.42 [95% confidence interval (CI): 0.93-2.17, p = 0.109]; when only trials of a higher quality were used, a pooled relative risk estimate of 2.05 (95% CI: 1.30-3.23, p = 0.002) was obtained.
  
  
  CONCLUSIONS
  Pooled results demonstrated a modest efficacy of AZA for the treatment of ulcerative colitis. However, the use of AZA for the management of UC is not based on high-quality evidence.
authors.affiliation: Division of Gastroenterology and Hepatology, University of Calgary Health Sciences Centre, G 087, 3330 Hospital Drive, NW, Calgary, AB, Canada.
authors.forename: Yvette
authors.initials: Y
authors.lastname: Leung
authors.forename: Remo
authors.initials: R
authors.lastname: Panaccione
authors.forename: Brenda
authors.initials: B
authors.lastname: Hemmelgarn
authors.forename: Jennifer
authors.initials: J
authors.lastname: Jones
mesh_terms: D000963:Antimetabolites / Q000627:therapeutic use*; D001379:Azathioprine / Q000627:therapeutic use*; D003093:Colitis, Ulcerative / Q000188:drug therapy*; D019317:Evidence-Based Medicine; D006801:Humans; D015122:Mercaptopurine / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic
chemical_list: D000963:Antimetabolites; D015122:Mercaptopurine; D001379:Azathioprine