Background: Large-scale studies of rabeprazole-based Helicobacter pylori eradication therapy have not been reported in Japan.
Aims: To evaluate H. pylori eradication by rabeprazole-based therapy with reference to antibiotic susceptibility, CYP2C19 genotype, and rabeprazole and clarithromycin dosages.
Methods: From 35 centres 479 H. pylori-positive patients with gastric or duodenal ulcer were randomized to four treatment groups: Group 1 (10 mg rabeprazole + 750 mg amoxicillin + 200 mg clarithromycin twice daily for 7 days); Group 2 (10 mg, 750 mg, 400 mg); Group 3 (20 mg, 750 mg, 200 mg) and Group 4 (20 mg, 750 mg, 400 mg).
Results: Eradication rates were 86% (102 of 119), 89% (97 of 109), 91% (106 of 116) and 90% (104 of 115) for Groups 1-4, respectively. The eradication rate was 95% (360 of 379) for clarithromycin-susceptible strains, and 50% (30 of 60) for clarithromycin-resistant strains. The eradication rates were 88% (332 of 379) and 96% (77 of 80) in extensive metabolizers and poor metabolizers, respectively.
Conclusions: Rabeprazole-based therapies achieved 50% eradication of clarithromycin-resistant H. pylori, and even achieved good rates in extensive metabolizers. Accordingly, rabeprazole can be recommended as part of a first-line proton pump inhibitor-based triple therapy for H. pylori.