Variability in CYP2C9 allele frequency: A pilot study of its predicted impact on warfarin response among healthy South and North Indians.
Journal Title: Pharmacological Reports - Year 2013, Vol 65, Issue 1
Abstract
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: Genotyping was carried out by PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) technique in 209 North Indians (NI) and 82 South Indians (SI). Warfarin maintenance dose was predicted for all subjects based on FDA approved genotype-based dose estimates from revised COUMADIN medication guide. Fisher exact test and Χ2 test were applied to compare categorical data among the SI and NI groups. Results: In SI and NI, the allele frequency of CYP2C9*2 was 0.006 and 0.05 (significant variation; p < 0.001); of CYP2C9*3 was 0.09 and 0.11; and of VKORC1-1639A was 0.14 and 0.19 (not significant), respectively. The variation in the frequency of combined CYP2C9/ VKORC1 genotypes revealed plausible difference in warfarin response among SI and NI. Based on the FDA approved revised dosing guidelines, significantly higher percentage of NI were likely to require intermediate dose (3-4 mg/day; p = 0.015, RR = 2.16) and were also predicted to have an increased risk of bleeding episodes and over anticoagulation (p = 0.012, RR = 1.93). Conclusions: Genotype frequency of CYP2C9 and VKORC1 SNPs is variable among the two ethno-geographically distinct Indian populations. This could translate into diverse warfarin response among the Indian population.
Authors and Affiliations
Risha Nahar, Roumi Deb, Renu Saxena, Ratna Puri, Ishwar Verma
Influence of the antagonist of the glycine site of NMDA receptors, MRZ 2/576, on the anticonvulsant activity of conventional antiepileptic drugs in mice.
The purpose of this study was to evaluate the influence of the glycine site antagonist of the NMDA receptor, MRZ 2/576 (8-chloro-4-hydroxy-1-oxo-1,2-dihydropyridazino[4,5-b]quinolin-5-oxide choline salt), on the anticonv...
Concomitant administration of fluoxetine and amantadine modulates the activity of peritoneal macrophages of rats subjected to a forced swimming test.
Recent studies show that administration of a non-competitive NMDA receptor antagonist, amantadine (AMA), potentiates the action of antidepressant drugs. Since antidepressants may modulate functioning of the immune system...
Metformin raises hydrogen sulfide tissue concentrations in various mouse organs.
Background: The epidemic of diabetes mellitus type 2 forces to intensive work on the disease medication. Metformin, the most widely prescribed insulin sensitizer, exerts pleiotropic actions on different tissues by not fu...
NADPH oxidase-derived reactive oxygen species in the regulation of endothelial phenotype.
Endothelial dysfunction comprising impairment of endothelium-dependent vasodilator function and increased endothelial activation contributes to the pathophysiology of cardiovascular diseases such as atherosclerosis, diab...
Novel variant of CYP2D6*6 is undetected by a commonly used genotyping procedure.
We report the identification of a novel and defective variant of the gene encoding cytochrome P450 2D6 (CYP2D6). This novel variant is a subtype of CYP2D6*6 that was undetected by a commercially available 5' exonuclease-...