One-week ranitidine bismuth citrate versus colloidal bismuth subcitrate-based anti-Helicobacter triple therapy:: A prospective randomized controlled trial

OBJECTIVE: The efficacy of 1 wk bismuth triple therapy is adversely influenced by the presence of metronidazole resistance. In vitro studies suggest that ranitidine bismuth citrate (RBC) plus metronidazole exhibit synergistic activity against metronidazole resistant strains of Helicobacter pylori (H. pylori). Whether this confers a superior clinical efficacy remains unproven. This study compared the efficacy of RBC-based triple therapy with bismuth triple therapy in eradication of H. pylori. METHODS: Patients with H. pylori-related ulcer disease or gastritis were randomized to receive either 400/mg of RBC twice daily plus 400/mg of metronidazole and 500/mg of tetracycline four times daily for 1 wk (RMT) or 120/mg of colloidal bismuth subcitrate, 400/mg of metronidazole, and 500/mg of tetracycline, all given four times daily for 1 wk (BMT). Metronidazole susceptibility was determined by the E-test and pretreatment resistance was defined as minimum inhibitory concentration greater than or equal to 32/mg/L. RESULTS: Of 100 consecutive patients randomized, two patients were lost to follow-up in each group. Forty-three of 85 (51%) H. pylori isolates were metronidazole resistant. Perprotocol cure rate for RMT and BMT was 49 of 41 (98%) and 37 of 44 (84%), respectively (p = 0.058). Intent-to-treat cure rate for RMT and BMT was 46 of 50 and 41 of 50, respectively (92% vs 82%,p = 0.23). A significantly higher eradication of metronidazole resistant H. pylori was observed in the RMT group (25 of 25, 100%) than in the BMT group (12 of 16, 75%), (p = 0.018). Side effects observed in the two treatment groups were comparable. CONCLUSIONS: One week of RBC triple therapy with metronidazole and tetracycline is an effective anti-Helicobacter therapy. This regimen is more appropriate in areas of high prevalence of metronidazole resistance. (Am J Gastroenterol 1999;94:721-724. (C) 1999 by Am. Cell. of Gastroenterology).