title: Ranitidine and cimetidine in the healing of duodenal ulcer: meta-analysis of comparative clinical trials.
abstract: All available ranitidine and cimetidine comparative trials in acute duodenal ulcer disease were examined: of the 44 trials, 36 favoured ranitidine, and there was an overall difference in ulcer healing of 7%. Further stratification enabled examination of trials with common attributes: the most frequent endoscopic assessment was at 4 weeks to compare ranitidine 150 mg twice daily with cimetidine 1 g day-1 or 400 mg b.d. Twenty of these trials had sufficient data to permit pooling. Ranitidine was favoured in 18/20 trials and in three the differences achieved statistical significance. Results of the trials were combined using meta-analysis to calculate differences in ulcer healing. Most studies had sample sizes that were insufficient to detect clinically-important differences; the power to detect a 20% difference was less than 80% in 15/20 trials, and for a 10% difference was less than 80% in all but one trial. Fifteen trials compared ranitidine 150 mg b.d. with cimetidine 1 g day-1: healing after 4 weeks therapy was overall 6% greater for ranitidine. This was statistically significant (P less than 0.05) and the combined total number of patients had a power of 83% to detect this difference. In five trials the dose of cimetidine used was 400 mg b.d.: the 12% difference in healing in favour of ranitidine 150 mg b.d. was statistically significant, and the combined trials had a power of 95% to detect this difference. Ranitidine 150 mg twice daily heals significantly more duodenal ulcers after 4 weeks of therapy than either cimetidine 400 mg b.d. or cimetidine 1 g day-1.
authors.affiliation: Department of Gastroenterology, Glaxo Group Research Ltd, Greenford, UK.
authors.forename: R L
authors.initials: RL
authors.lastname: McIsaac
authors.forename: I
authors.initials: I
authors.lastname: McCanless
authors.forename: K
authors.initials: K
authors.lastname: Summers
authors.forename: J R
authors.initials: JR
authors.lastname: Wood
mesh_terms: D002927:Cimetidine / Q000627:therapeutic use*; D004381:Duodenal Ulcer / Q000188:drug therapy*; D006801:Humans; D015201:Meta-Analysis as Topic; D011899:Ranitidine / Q000627:therapeutic use*
chemical_list: D002927:Cimetidine; D011899:Ranitidine