title: Efficacy of topical 5-aminosalicylates in preventing relapse of quiescent ulcerative colitis: a meta-analysis.
abstract: OBJECTIVE
  Topical 5-aminosalicylates (5-ASAs) such as mesalamine are effective in inducing remission in patients with mild to moderately active ulcerative colitis (UC). However, there has been no meta-analysis of their efficacy in preventing relapse of quiescent UC.
  
  
  METHODS
  We searched MEDLINE, EMBASE, and the Cochrane central register of controlled trials through July 2011 for randomized controlled trials comparing the effects of topical 5-ASAs with placebo in adults with quiescent UC. Dichotomous data were pooled to obtain relative risk (RR) of relapse of disease activity. The number needed to treat (NNT) was calculated from the reciprocal of the risk difference. Adverse events data were summarized.
  
  
  RESULTS
  The search identified 3061 citations; we analyzed data from seven (555 patients). All trials used mesalamine, but only one included patients with extensive disease. The duration of therapy ranged from 6-24 months. The RR of relapse of disease activity in patients with quiescent UC who were given topical mesalamine, compared with placebo, was 0.60 (95% confidence interval, 0.49-0.73; NNT = 3); there was no significant heterogeneity between studies (I(2) = 21%, P = .27). No significant differences in rates of adverse events rates were detected (RR = 1.01; 95% confidence interval, 0.59-1.72).
  
  
  CONCLUSIONS
  On the basis of a meta-analysis of 7 randomized controlled trials, topical mesalamine is effective in preventing relapse of quiescent UC, with no greater number of adverse events than placebo. However, because most studies included only patients with left-sided disease or proctitis, the efficacy of topical mesalamine in preventing relapse in patients with more extensive quiescent UC is not known.
authors.affiliation: Leeds Gastroenterology Institute, Leeds General Infirmary, Leeds, United Kingdom. alexf12399@yahoo.com
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Ford
authors.forename: Khurram J
authors.initials: KJ
authors.lastname: Khan
authors.forename: William J
authors.initials: WJ
authors.lastname: Sandborn
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Hanauer
authors.forename: Paul
authors.initials: P
authors.lastname: Moayyedi
mesh_terms: D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage* / Q000009:adverse effects; D003093:Colitis, Ulcerative / Q000188:drug therapy* / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D019804:Mesalamine / Q000008:administration & dosage* / Q000009:adverse effects; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D055502:Secondary Prevention; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000893:Anti-Inflammatory Agents; D019804:Mesalamine