Various durations of a standard regimen (amoxycillin, metronidazole, colloidal bismuth sub-citrate for 2 weeks or with additional ranitidine for 1 or 2 weeks) on eradication of Helicobacter pylori in Iranian peptic ulcer patients. A randomized controlled trial

INTRODUCTION: One of the most economical and effective therapeutic regimens for eradication of Helicobacter pylori is the classic triple therapy with amoxycillin or tetracycline, metronidazole and a bismuth derivative. Addition of H2-receptor antagonists to these drugs may heighten the rate of eradication and shorten the duration. We therefore performed a randomized controlled trial comparing twice daily metronidazole, bismuth derivative and amoxycillin for 2 weeks with additional ranitidine for 1 or 2 weeks. PATIENTS AND METHODS: In total, 240 adult patients with duodenal ulcer and H. pylori infection were randomly assigned to one of the following regimens: (1) amoxycillin 1 g bid, metronidazole 500 mg bid, bismuth sub-citrate 240 mg bid and ranitidine 300 mg bid for 1 week; (2) triple therapy without ranitidine for 2 weeks; or (3) triple therapy plus ranitidine 300 mg bid for 2 weeks. Side-effects of the drugs were evaluated two weeks after starting the treatment. The rapid urease test and histology from antrum and corpus, and/or 14C- urea breath test were used to determine H. pylori eradication six weeks after starting the treatment. RESULTS: In total, 195 patients were followed up for 6 weeks. The most frequent drug side-effects were unpleasant taste (46%), dry mouth (41%) and fatigue (26%), which had an equal distribution in all treatment groups. Endoscopy and 14C- urea breath test were performed for 178 and 123 patients, respectively. Eradication of H. pylori was documented in 19/64 (29.7%), 29/63 (46%) and 50/68 (73.5%) of patients in groups 1, 2 and 3, respectively (P < 0.000001 for group 1 versus group 3; P < 0.0014 for group 2 versus group 3; difference not significant for group 1 versus group 2). An intention-to-treat analysis showed eradication rates of 19/80 (23.75%), 29/80 (36.25%) and 50/80 (62.5%) for groups 1, 2 and 3, respectively. At four weeks post-treatment, the most sensitive test for evaluation of eradication of H. pylori was histology. CONCLUSION: Although combined use of an H2-receptor antagonist and twice daily triple therapy in a two-week regimen is more effective than two-week triple or one-week quadruple therapy in Iranian patients, none of these regimens is ideal in countries with a probable high rate of resistant and strongly toxic strains of H. pylori.