Warfarin is a commonly used anticoagulant with a narrow therapeutic range and risk of hemorrhagic complications. After CYP2C9 and VKORC1, CYP4F2 was confirmed as the third principle genetic determinant of warfarin dose variability. CYP4F2 functions as a vitamin K1 (VK1) oxidase, a counterpart to vitamin K oxidize reductase (encoded by VKORC1) in limiting excessive accumulation of VK1 in vitamin...

Warfarin is widely prescribed for patients with the risk of thromboembolism around the world. The inter-individual and inter-racial differences in appropriate dosage depend highly on age, body weight, and genetic factors. A lot of studies including genome-wide association studies revealed that vitamin K epoxide reductase complex, subunit 1 (VKORC1) G-1639A and Cytochrome P450 (CYP) 2C9 A1075C a...

Single-nucleotide polymorphisms in genes that affect warfarin metabolism (cytochrome P450 2C9 gene, CYP2C9) and response (vitamin K epoxide reductase complex 1 gene, VKORC1) have an important influence on warfarin therapy, particularly during initiation; however, there is a lack of consensus regarding the optimal pharmacogenetics-based initiation strategy. We conducted a prospective cohort stud...

BACKGROUND Wide variability exists in the frequency of pharmacogeneticmarkers for anticoagulant response in different populations. There is insufficient data on the prevalence of these variant genotypes in the Indian population. This study aims to determine the frequency of various genotype combinations of CYP2C9*2, *3 and VKORC1-1639G>A polymorphisms in the South and North Indians. METHODS G...

The systematic use of antivitamin K anticoagulants (AVK) as rodenticides caused the selection of rats resistant to AVKs. The resistance is mainly associated to genetic polymorphisms in the Vkorc1 gene encoding the VKORC1 enzyme responsible for the reduction of vitamin K 2,3-epoxide to vitamin K. Five major mutations, which are responsible for AVK resistance, have been described. Possible explan...

Current dosing algorithms do not account for genetic and environmental factors for warfarin dose determinations. This study investigated the contribution of age, CYP2C9 and VKORC1 genotype, and body size to warfarin-dose requirements. Studied were 297 patients with stable anticoagulation with a target international normalized ratio (INR) of 2.0 to 3.0. Genetic analyses for CYP2C9 (*2 and *3 all...

The aim of the study is to explore the contribution of genetic factors related either to drug metabolism (cytochrome P450 2C9) or to drug target (vitamin K epoxide reductase) to variability in the response to acenocoumarol among 222 healthy volunteers after a single oral dose. Associations between a pharmacodynamic index (reduction in factor VII activity and international normalized ratio [INR]...

Anticoagulant compounds, i.e., derivatives of either 4-hydroxycoumarin (e.g., warfarin, bromadiolone) or indane-1,3-dione (e.g., diphacinone, chlorophacinone), have been in worldwide use as rodenticides for >50 years. These compounds inhibit blood coagulation by repression of the vitamin K reductase reaction (VKOR). Anticoagulant-resistant rodent populations have been reported from many countri...

The aim of the study is to explore the contribution of genetic factors related either to drug metabolism (cytochrome P450 2C9) or to drug target (vitamin K epoxide reductase) to variability in the response to acenocoumarol among 222 healthy volunteers after a single oral dose. Associations between a pharmacodynamic index (reduction in factor VII activity and international normalized ratio [INR]...

1Food and Drug Laboratory Research Center, Ministry of Health and Medical Education, Tehran, IR Iran 2Day General Hospital Laboratory, Tehran, IR Iran 3Department of Biotechnology, Shahid Beheshti University of Medical Sciences, Tehran, IR Iran 4Department of Research and Development, Production and Research Complex, Pasteur Institute, Tehran, IR Iran 5Department of Epidemiology, Pasteur Instit...