Plasma OPZ area under curve (AUC) after a single oral dose of 20 mg OPZ was 421 ng.h/ml in normal homozygotes, 1403 ng.h/ml in heterozygotes and 5109 ng.h/ml in healthy Japanese mutant homozygotes.
(13) In a similar study dual therapy with 20 mg OPZ (bid) and 500 mg AMC (qid) for 1 wk demonstrated 100 per cent eradication in Japanese mutant homozygotes compared to 40 and 42 per cent in normal homozygotes and heterozygotes, respectively.
Hsu et al (15) reported that 20 mg OPZ (bid), 1000 mg AMC (bid) and 500 mg TNZ (bid) for 14 days achieved 88 per cent (95% CI: 79-96) eradication of H.
Lomac capsules (Cipla Ltd., Bombay, India) containing 20 mg OPZ were purchased from local suppliers.
The major PPIs are OPZ, lansoprazole (LPZ), pantoprazole (PPZ) and rabeprazole (RPZ).
Table I summarizes different studies correlating pharmacogenetics of CYP2C19 with pharmacokinetics and pharmacodynamics of OPZ, LPZ and RPZ in various ethnic groups.
OPZ is known to increase the concentration of AMC in gastric juice (43).