The Efficacy and Safety of 14-day Rabeprazole Plus Amoxicillin High Dose Dual Therapy by Comparing to 14-day Rabeprazole-Containing Hybrid Therapy for the Naïve Helicobacter pylori Infection in Taiwan: A Randomized Controlled Trial.

INTRODUCTION: High-dose dual therapy (HDDT) can attain acceptable eradication rates provided that the optimal doses, timing and treatment duration are applied. The existing evidence still shows inconsistent reports (< 90%) on HDDT therapy except in some Asian countries. We aimed to assess and compare the efficacy of 14-day HDDT by comparing it to 14-day rabeprazole-containing hybrid therapy (HT) and to investigate the host and bacterial factors predicting the treatment outcomes of eradication therapies.

METHODS: In this open-label, randomized controlled trial, we recruited 243 naïve Helicobacter pylori-infected patients from September 1, 2018, to November 30, 2021. They were randomly allocated (1:1) to the HDDT group (rabeprazole 20 mg and amoxicillin 750 mg q.i.d for 14 days, n = 122) and the HT group (rabeprazole 20 mg and amoxicillin 1 g b.i.d. for 7 days, followed by rabeprazole 20 mg, amoxicillin 1 g, clarithromycin 500 mg and metronidazole 500 mg b.i.d. for 7 days, n = 121). Twelve patients were absent during follow-up in the HDDT group and 4 in the HT group, resulting in 110 for the HDDT group and 117 for HT group in the per protocol (PP) study. The outcome was determined by urea breath tests 8 weeks later.

RESULTS: The eradication rates for the HDDT and HT groups were 77.0% (95% confidence interval [CI]: 68.5% to 84.1%) and 94.2% (95% CI: 88.4% to 97.6%) (P < 0.001) in intention-to-treat analysis; 85.5% (95% CI: 77.5% to 91.5%) and 97.4% [95% CI: 92.6% to 99.5%] (P = 0.001) in per protocol analysis. The adverse event rates were 7.3% in the HDDT group and 14.5% in the HT group (P = 0.081). The habit of coffee drinking was the dependent factor for eradication failure in the HDDT group (88.2% vs. 68.8%, P = 0.040), but had no influence in the HT group (97.9% versus 95.0%, P = 0.449) in the univariate analysis.

CONCLUSION: This study demonstrated that 14-day rabeprazole-containing HDDT did not achieve > 90% eradication rates for first-line H. pylori eradication as 14-day rabeprazole-containing HT did. HDDT is a potentially beneficial combination, which involves only two drugs with mild adverse effects; more precise studies are urged to find answers regarding these failures. This clinical trial was registered retrospectively on 28 November, 2021, as ClinicalTrials.gov identifier: NCT05152004.