Importance of CYP2C19 genetic polymorphism in the eradication of Helicobacter pylori in north Indians.
OBJECTIVE
Genetic polymorphism of CYP2C19 is known to occur with a frequency of 12 per cent in north Indian population. But no study correlated CYP2C19 genetic polymorphism with eradication of Helicobacter pylori in north Indian gastritis patients positive for H. pylori and hence this study.


METHODS
Ninety one consecutive patients positive for H. pylori fulfilling the study criteria were phenotyped and genotyped for CYP2C19. They were given 20 mg omeprazole (OPZ), 750 mg amoxicillin (AMC) and 500 mg tinidazole (TNZ) (bid) for 7 days followed by 20 mg OPZ (qd) for 21 days. Non eradicated extensive metabolizers (EMs) were retreated with 40 mg OPZ (bid) and 500 mg AMC (qid) for 14 days.


RESULTS
EMs and poor metabolizers (PMs) excreted 4.26 +/- 0.34 (95% CI 3.59-4.92) and 0.73 +/- 0.05 (95% CI 0.63-0.82) micromol 5-OH-OPZ in 8 h, respectively. After initial therapy, EMs demonstrated 37 per cent (95% CI: 24.5-49.5) and PMs 92 per cent (95% CI: 77-107) eradication of H. pylori. Non eradicated EMs after retreatment demonstrated 90 per cent (95% CI: 79-101) eradication.


CONCLUSIONS
This study demonstrated a direct correlation between CYP2C19 genetic polymorphism and H. pylori eradication in north Indian patients with gastritis. Knowing the CYP2C19 phenotype of a patient may help in prescribing optimum dose of proton pump inhibitor to achieve better therapeutic outcome.
Chaudhry
A S
AS
Department of Biochemistry, Postgraduate Institute of Medical Education & Research, Chandigarh, India.
Kochhar
R
R
Kohli
K K
KK
D000477:Alkylating Agents / Q000627:therapeutic use; D000658:Amoxicillin / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000897:Anti-Ulcer Agents / Q000627:therapeutic use; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D065731:Cytochrome P-450 CYP2C19; D005838:Genotype; D016481:Helicobacter Infections / Q000188:drug therapy / Q000235:genetics*; D016480:Helicobacter pylori / Q000472:pathogenicity*; D006801:Humans; D007194:India; D009853:Omeprazole / Q000627:therapeutic use; D010641:Phenotype; D011110:Polymorphism, Genetic; D014011:Tinidazole / Q000627:therapeutic use; D016896:Treatment Outcome
D000477:Alkylating Agents; D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D014011:Tinidazole; D000658:Amoxicillin; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19; D009853:Omeprazole