Esomeprazole 40 mg twice daily in triple therapy and the efficacy of Helicobacter pylori eradication related to CYP2C19 metabolism

Summary Aim : To determine whether an increased dosage of esomeprazole 40 mg twice daily in triple therapy improved the Helicobacter pylori eradication rate for patients with different genotypes of S‐mephenytoin 4′‐hydroxylase (CYP2C19). Methods : Two hundred H. pylori‐infected dyspeptic patients were randomized to receive clarithromycin 500 mg twice daily and amoxicillin 1 g twice daily plus either omeprazole 20 mg or esomeprazole 40 mg twice daily for 1 week. Six weeks later, the success of H. pylori eradication was defined. The genotyping of CYP2C19 in each patient was defined as homologous, heterologous extensive metabolizer or poor metabolizer. Results : The age, gender, drug compliance and proportion of CYP2C19 genotypes were similar between the two groups. The H. pylori eradication rates were also similar between the omeprazole group and the esomeprazole group (intention‐to‐treat analysis: 79% vs. 86%, P > 0.05; per‐protocol analysis: 85% vs. 94%, P > 0.05). For patients classified as homologous extensive metabolizers, the per‐protocol H. pylori eradication rate was significantly higher in the esomeprazole group than in the omeprazole group (93% vs. 76%, P