Therapeutic effects of 10 mg/day rabeprazole administration on reflux esophagitis was not influenced by the CYP2C19 polymorphism

Background: The acid suppressive effects of omeprazole (OPZ) and lansoprazole (LPZ) are influenced by the CYP2C19 polymorphism. On the other hand, some investigators have reported that acid suppressive effect of rabeprazole (RPZ) was not significantly affected by CYP2C19. The present study was designed to investigate whether the CYP2C19 genotype is related to the healing of reflux esophagitis (RE) in treatment with RPZ 10 mg. Methods: One hundred and three Japanese patients with RE were treated with daily oral administration of 10 mg RPZ. At 4 and 8 weeks after the start of treatment, healing of RE was evaluated endoscopically. The CYP2C19 genotype was investigated before the treatment. Results: At 4 weeks after the start of treatment, the healing rates for homo‐extensive metabolizer, hetero‐extensive metabolizer, and poor metabolizer patients were 86.1% (31/36), 92.0% (46/50), and 82.4% (14/17), respectively, and at 8 weeks after the start of treatment, the healing rates were 86.1% (31/36), 92.0% (46/50), and 82.4% (14/17), respectively. There were no significant differences in the healing rate of RE among the three genotypes at either 4 or 8 weeks after the start of treatment. Conclusions: The therapeutic effects of 10 mg/day RPZ administration on RE may be uninfluenced by the CYP2C19 polymorphism.