CYP2C19 genotype-related efficacy of omeprazole for the treatment of infection caused by Helicobacter pylori

Yusuke Tanigawara, Nobuo Aoyama, Tomoko Kita, Katsuro Shirakawa, Fusao Komada, Masato Kasuga, Katsuhiko Okumura

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186 Citations (Scopus)


Objective: Omeprazole is used for the treatment of infection caused by Helicobacter pylori, and it is metabolized by the polymorphic cytochrome P4502C19 (CYP2C19). We have found that the anti-H pylori efficacy by the combination of omeprazole and antibiotics is related to the CYP2C19 genotype. Methods: One hundred eight patients with cultured H pylori-positive gastritis or peptic ulcer were treated with three regimens: quadruple treatment without proton pump inhibitors (n = 25), dual treatment with omeprazole and amoxicillin (INN, amoxicilline) (n = 26), and triple treatment with omeprazole, amoxicillin, and clarithromycin (n = 57). The CYP2C19 genotype was determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and the assessment of the eradication of H pylori was based on all negative examinations, including culture, histology, and 13C-urea breath test. Results: The eradication rates for the extensive metabolizers were 50% and 86% for the dual and triple treatments, respectively. In contrast, all of the poor metabolizers treated with omeprazole and antibiotics (n = 15) showed an eradication of H pylori. Conclusion: The anti-H pylori effect of dual treatment is highly efficient for CYP2C19 poor metabolizers, which suggests that clarithromycin is not necessary as a first line of therapy for this type of patients. Genotyping can provide a choice for the optimal regimen based on individual CYP2C19 genotype.

Original languageEnglish
Pages (from-to)528-534
Number of pages7
JournalClinical Pharmacology and Therapeutics
Issue number5
Publication statusPublished - 1999

ASJC Scopus subject areas

  • Pharmacology
  • Pharmacology (medical)


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