CYP2C19 polymorphism is associated with pretreatment drug response prediction, metabolism, and disposition. Pakistan consists of a population comprising of various ethnic groups residing in different regions of the country each claiming diverse ethnic origins. The identification of CYP450 genotypic composition of these populations is therefore necessary to avoid adverse drug reactions in these ...

The amino acid residues affecting the substrate specificity of human cytochrome P450 CYP2C9 and CYP2C19 for their metabolic activities were investigated using chimeras and mutant enzymes, which were constructed by replacing the corresponding residues. Although CYP2C19 showed nearly the same tolbutamide hydroxylase activity as CYP2C9, the activities for the CYP2C19(H99I) mutant and the chimeras ...

Cytochrome P450 2C19 (CYP2C19) is the enzyme responsible for the metabolism of a number of drugs, including anticonvulsants and antidepressants. We have developed a semi-quantitative competitive RT-PCR assay to estimate the degree of expression of the full-length CYP2C19 message. This assay used a known quantity of internally deleted CYP2C19 RNA to quantitate the RT-PCR products of the CYP2C19 ...

The aim of this study was to investigate the association of genetic variants of CYP2C19 (CYP2C19*2, CYP2C19*3 and CYP2C19*17 alleles) and voriconazole trough plasma concentrations in Thai patients with invasive fungal infection. A total of 285 samples from patients with invasive fungal infection and treated with voriconazole were prospectively enrolled. At steady state, trough voriconazole conc...

This study was to determine the impact of adjunctive Buchang Naoxintong Jiaonang (BNJ) to clopidogrel on volunteers with the CYP2C19*2 gene mutation accompanied with qi deficiency and blood stasis (QDBS) constitution. Eighteen males with QDBS constitution were selected, who were 6 CYP2C19*1/*1, 6 CYP2C19*1/*2, and 6 CYP2C19*2/*2, and signed informed consent. Results showed that the maximal plat...

BACKGROUND Cytochrome P450 2C19 (CYP2C19) is important in metabolism of wide range of drugs. CYP2C19*17 is a novel variant allele which increases gene transcription and therefore results in ultra-rapid metabolizer phenotype (URM). Distribution of this variant allele has not been well studied worldwide. The aim of present study was to investigate allele and genotype frequencies of CYP2C19*17 in ...

A series of clinical studies on the cytochrome P450 2C19 (CYP2C19) genotype and the pharmacokinetics and pharmacodynamics of three proton pump inhibitors (PPIs), omeprazole, lansoprazole and rabeprazole, have been conducted to establish the individualized pharmacotherapy based on the CYP2C19 genotyping, and in the present study, the CYP2C19 genotype-dependency was more pronounced for omeprazole...

Systemic exposure of the antidepressant S-citalopram (escitalopram, SCIT) differs several-fold according to variable cytochrome P450 2C19 activity, demonstrating the importance of this enzyme for the metabolic clearance of SCIT in vivo. However, previous studies have indicated that the involvement of CYP2C19 in formation of the metabolite N-desmethyl S-citalopram (SDCIT) is limited. Therefore, ...

We tested the hypothesis that the stable isotope [(13)C]pantoprazole is O-demethylated by cytochrome P450 CYP2C19 and that the (13)CO(2) produced and exhaled in breath as a result can serve as a safe, rapid, and noninvasive phenotyping marker of CYP2C19 activity in vivo. Healthy volunteers who had been genotyped for the CYP2C19(*)2, CYP2C19(*)3, and CYP2C19(*)17 alleles were administered a sing...