Dose–response relationships of rabeprazole 5, 10, 20, and 40 mg once daily on suppression of gastric acid secretion through the night in healthy Japanese individuals with different CYP2C19 genotypes

Purpose This study was designed to investigate the antisecretory activity of rabeprazole administered once daily in doses of 5, 10, 20, and 40 mg and different cytochrome P450 2C19 (CYP2C19) genotypes on gastric pH in healthy individuals. Additional objectives were delineating the nighttime from the daytime effect and determining the relationships between the pharmacokinetics and pharmacodynamics of rabeprazole.