Abstract
Objective CYP2C19 metabolic activity influences the efficacy of Helicobacter pylori eradication therapies comprising PPIs. Rabeprazole (RPZ) and esomeprazole (EPZ) are PPIs not extensively metabolized by CYP2C19. The aim of this study was to elucidate whether or not first-line triple therapies using RPZ or EPZ are equally effective in Japanese patients with different CYP2C19 genotypes. Methods Two-hundred patients infected with H. pylori were randomized to receive one of the following regimens: amoxicillin (750 mg), clarithromycin (200 mg), and either esomeprazole (20 mg) (EAC group) or rabeprazole (10 mg) (RAC group), twice a day for one week. The CYP2C19 polymorphisms were determined by polymerase chain reaction and the serum level of pepsinogens was measured. Results The eradication rates of the EAC and RAC regimens were 79.8% (95% confidential interval: 71.7-89.0%) and 74.7% (66.0-83.4%), respectively, in a per protocol (PP) analysis (p=0.488). The eradication rates of the EAC and RAC regimens were not significantly different between patients with the homo EM genotype (p=0.999) or hetero IM or PM genotypes (p=0.286). A lower PG I/II ratio was associated with lower eradication rates (p=0.025). Conclusion Although the eradication rate was less than 80%, the EAC and RAC regimens were equally effective in each CYP2C19 genotype group. The PG I/II ratio was associated with the results of EAC and RAC therapy in this series of patients.