Cytochrome P450 (P450) protein-protein interactions have been shown to alter their catalytic activity. Furthermore, these interactions are isoform specific and can elicit activation, inhibition, or no effect on enzymatic activity. Studies show that these effects are also dependent on the protein partner cytochrome P450 reductase (CPR) and the order of protein addition to purified reconstituted ...

The requirement of varying doses of warfarin for different individuals can be explained by environmental and genetic factors. We evaluated the frequency of vitamin K epoxide reductase complex subunit 1 (VKORC1) and cytochrome P450 2C9 (CYP2C9) variants together with patientdemographic characteristics and investigated their association with warfarin dose requirement with the ob...

Cytochrome P450 2C9 (CYP2C9) is a polymorphic enzyme responsible for the metabolism of many important drugs, including diclofenac. CYP2C9*3 and CYP2C9*13 are the principal variant alleles found in the Chinese population. CYP2C9*3 has been reported to reduce the metabolism of diclofenac and alter the extent of drug-drug interactions (DDIs). The effects of CYP2C9*13 on diclofenac metabolism are n...

OBJECTIVE CYP2C9 is a major enzyme in human drug metabolism and the polymorphism observed in the corresponding gene may affect therapeutic outcome during treatment. The distribution of variant CYP2C9 alleles and prevalence of phenytoin adverse reactions were hereby investigated in a population of patients diagnosed with epilepsy. METHOD Allele-specific PCR analysis was carried out in order to...

OBJECTIVES Valproic acid (VPA)-induced adverse effects, which are sometimes serious in children, can be associated with alterations in VPA metabolism. VPA-evoked toxicity is attributed to both the parent compound and its unsaturated metabolites, primarily formed by the cytochrome P450 (CYP)2C9 enzyme. Thus, patients' CYP2C9-status may account for the predisposition to adverse reactions, and tes...

Cytochrome p450 (CYP) 2C9 hydroxylates about 16% of drugs in current clinical use. Of special interest are those with a narrow therapeutic index, such as S-warfarin, tolbutamide and phenytoin, where impairment in CYP2C9 metabolic activity might cause difficulties in dose adjustment as well as toxicity. Single-nucleotide polymorphisms (SNP) in the CYP2C9 gene have increasingly been recognized as...

background: north of iran is amongst high incidence rate areas of gastric carcinoma where environmental carcinogenic compounds especially agricultural pesticides are massively used. cytochrome p450 2e1 (cyp2e1) enzyme metabolically activates a large number of low molecular mass xenobiotics. the polymorphic nature of cyp2e1 gene control elements is associated with interindividual differences for...

The commonly prescribed antiepileptic drug phenytoin has a narrow therapeutic range and wide interindividual variability in clearance explained in part by CYP2C9 and CYP2C19 coding variants. After finding a paradoxically low urinary phenytoin metabolite (S)/(R) ratio in subjects receiving phenytoin maintenance therapy with a CYP2C9*1/*1 and CYP2C19*1/*2 genotype, we hypothesized that CYP2C9 reg...

Accumulating evidence indicates that CYP2C9 ranks amongst the most important drug metabolizing enzymes in humans. Substrates for CYP2C9 include fluoxetine, losartan, phenytoin, tolbutamide, torsemide, S-warfarin, and numerous NSAIDs. CYP2C9 activity in vivo is inducible by rifampicin. Evidence suggests that CYP2C9 substrates may also be induced variably by carbamazepine, ethanol and phenobarbit...

INTRODUCTION Genetic polymorphisms of CYP2C9 among different populations in different geographical regions could be different. CYP2C9 has been reported to be the enzyme responsible for the metabolism of many drugs, including warfarin and other drugs with a narrow therapeutic index. Realising the importance of inter-individual differences in the genetic profile in determining the outcome of a dr...