Objective: To investigate the effect of different S-mephenytoin 4'-hydroxylase (CYP2C19) genotype on the eradication rate of Helicobacter pylori (Hp) by different rabeprazole-based triple therapy in Chinese.
Methods: 128 subjects with Hp positive gastritis or peptic ulcers were randomly assigned to receive 10 mg rabeprazole twice daily with 1000 mg amoxicillin twice daily and 500 mg clarithromycin (RAC group) or 400 mg metronidazole (RAM group) twice daily for 1 week. The CYP2C19 genotype (homozygous extensive metabolizer, hom-Ems; heterozygous extensive metabolizer, het-Ems; or poor metabolizer, PMs) was determined by the polymerase chain reaction-restriction fragment length polymorphism method. More than 4 weeks after completion of treatment, Hp status was assessed by (13)C-urea breath test.
Results: The hom-Ems, het-Ems and PMs were 30.5%, 50.0% and 19.5% in 128 subjects, respectively. The eradication rates in the rabeprazole-amoxicillin-clarithromycin (RAC) for clarithromycin-sensitive strains and rabeprazole-amoxicillin-metronidazole (RAM) for metronidazole-sensitive strains groups were 98.1% and 91.3%, respectively, on a per protocol basis. It decreased significantly eradication rates of Hp because the prevalence of primary antimicrobial resistance was 66.8% for metronidazole. When the statistical significance of each parameter associated with treatment outcome was assessed with logistic regression analysis, CYP2C19 genetic polymorphism did not show significant effect on the efficacy of anti-Hp therapy with rabeprazole-based triple regimens.
Conclusions: The efficacy of rabeprazole-based triple regimens is less affected by the CYP2C19 genotype, the RAC regimen can be considered in Chinese.