Effect of genetic differences in omeprazole metabolism on cure rates for Helicobacter pylori infection and peptic ulcer.

BACKGROUND

Omeprazole is metabolized by S-mephenytoin 4'-hydroxylase (CYP2C19) in the liver. In persons with a poor-metabolizer genotype for CYP2C19, the therapeutic efficacy of omeprazole may be increased.

OBJECTIVE

To investigate whether CYP2C19 genotype status is associated with cure rates for Helicobacterpylori infection and peptic ulcer achieved by using dual therapy with omeprazole and amoxicillin.

DESIGN

Prospective cohort study.

SETTING

University hospital and health service center in Hamamatsu, Japan.

PATIENTS: 62 patients with peptic ulcer and H. pylori infection.

INTERVENTION: Omeprazole and amoxicillin.

MEASUREMENTS: CYP2C19 genotype status and cure rates for H. pylori infection and peptic ulcer.

RESULTS

Cure rates for H. pylori infection were 28.6% (95% CI, 13.1% to 48.7%), 60% (CI, 38.6% to 83.0%), and 100% (CI, 66.4% to 100%) in the rapid-, intermediate-, and poor-metabolizer groups, respectively. Healing rates for both duodenal and gastric ulcer in the three groups were roughly parallel with cure rates for H. pylori infection.

CONCLUSION

The results of the genotyping test for CYP2C19 seem to predict cure of H. pylori infection and peptic ulcer in patients who receive dual therapy with omeprazole and amoxicillin.