A Comparative Study of Proton-pump Inhibitor Tests for Chinese Reflux Patients in Relation to the CYP2C19 Genotypes

Backgrounds \& Aims: Proton-pump inhibitor (PPI) test has been proposed as a valuable tool in the diagnosis of gastroesophageal reflux disease (GERD) in Western populations. We assumed that a higher prevalence of poor metabolizers in Chinese population might affect the diagnostic accuracy of a PPI test. Methods: In this open-label, randomized trial, patients with symptoms suggestive of GERD were randomly assigned to receive a 2-week test with daily rabeprazole 40-mg or daily pantoprazole 80-mg after diagnostic endoscopy. Therapeutic response was assessed with a five-grade daily record. Genotypes of cytochrome P450 (CYP) 2C19 polymorphism were determined.