VKORC1 and CYP2C9 polymorphisms are associated with warfarin dose requirements in Turkish patients

• Published in: European journal of clinical pharmacology 2008-09, Vol.64 (9), p.889-894
• Main Authors: Oner Ozgon, G., Langaee, T. Y., Feng, H., Buyru, N., Ulutin, T., Hatemi, A. C., Siva, A., Saip, S., Johnson, J. A.
• Format: Article
• Language: English
• Subjects: Adult; Aged; Anticoagulants - administration & dosage; Anticoagulants - therapeutic use; Aryl Hydrocarbon Hydroxylases - genetics; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cytochrome P-450 CYP2C9; Dose-Response Relationship, Drug; Drug dosages; Drug therapy; Female; Genotype & phenotype; Humans; International Normalized Ratio; Male; Medical sciences; Middle Aged; Minority & ethnic groups; Mixed Function Oxygenases - genetics; Pharmacogenetics; Pharmacology; Pharmacology. Drug treatments; Pharmacology/Toxicology; Polymorphism; Polymorphism, Genetic; Turkey; Vitamin K Epoxide Reductases; Warfarin - administration & dosage; Warfarin - therapeutic use
• ISSN: 0031-6970; 1432-1041
• DOI: 10.1007/s00228-008-0507-5

Objectives The objective of this study was to determine the quantitative influence of vitamin K epoxide reductase complex subunit 1 ( VKORC1 ) and cytochrome P450 2C9 ( CYP 2C9 ) polymorphisms on warfarin dose requirements in Turkish patients. Methods A total of 205 patients taking warfarin for >2 months were enrolled in the study. Deoxyribonucleic acid (DNA) samples from these patients were genotyped for polymorphisms in VKORC1 and CYP2C9 genes. A linear regression analysis was used to determine the independent effects of genetic and non-genetic factors on mean warfarin dose requirements. Results The VKORC1 promoter polymorphism (3673 G>A) was associated with differences in weekly mean varfarin dose: for GG genotype the dose was 43.18 mg/week, for GA genotype 33.78 mg/week and for AA genoype 25.83 mg/week ( P