Background/aims: In Japan, eradication regimens consisting of a proton pump inhibitor (PPI) + amoxicillin (AMPC) + clarithromycin (CAM) (PPI/AC) for 1 week have been conducted. In the present study, we assessed the eradication rates following treatment with low doses of various PPIs.
Methodology: 135 patients were divided randomly into one of three 7-day regimens: (i) omeprazole (OPZ) 20 mg/day + AMPC 1500 mg/day + CAM 600 mg/day (OAC); (ii) lansoprazole (LPZ) 30 mg + AMPC 1500 mg/day + CAM 600 mg/day (LAC); and (iii) rabeprazole (RPZ) 10mg/day + AMPC 1500 mg/ day + CAM 600 mg/day (RAC). The genetic polymorphism of CYP2C19 was also examined.
Results: The eradication rates according to the treatment regimen were as follows: 69.9% (31/45) for OAC, 62.2% (28/45) for LAC, and 71.1% (32/45) for RPZ. No significant differences were found among the regimens. Moreover, eradication rates, according to CYP2C19 phenotype (homozygous extensive metabolizer (EM), heterozygous EM, and poor metabolizer) were: 68.6% (35/51), 77.4% (41/53), and 82.4% (14/17), respectively.
Conclusions: In PPI/AC therapy, the eradication rate for each low-dose PPI was 60-70%, which is low. Based on previous reports, it is considered that doses greater than 40 mg/day OPZ, 60 mg/day LPZ, and 20 mg/day RPZ are required.