Coumarin oral anticoagulant drugs have proven to be effective for the prevention of thromboembolic events. World-wide, warfarin is the most prescribed drug. In Europe, acenocoumarol and phenprocoumon are also administered. Yet it has been proven that variant alleles of the VKORC1 and CYP2C9 genotypes influence the pharmacokinetics and pharmacodynamics of these drugs. The combination of these tw...

SUMMARY Warfarin-induced bleeding complications and high inter-patient variability are major hindrances to oral anticoagulant therapy. The present study identifies the influence of VKORC1 diplotypes, CYP2C9 and CYP2C19 variants on warfarin disposition and dose requirements in Chinese patients (n=107). The study subjects were genotyped for VKORC1, CYP2C9 and CYP2C19 polymorphic variants. Weekly ...

BACKGROUND AND PURPOSE Variant alleles of CYP2C9 and VKORC1 account for differences in anticoagulation response. We sought to establish a warfarin dosing formula for individualized target International Normalization Ratio of Prothrombin Times (INRs) using data from single nucleotide polymorphisms (SNPs) in VKORC1 and CYP2C9 in Korean patients. METHODS Ischemic stroke patients displaying stabl...

Thromb Haemost 2008; 100: 175–176 More than 60 years after its successful introduction for the prevention of thromboembolic events, the coumarin anticoagulant warfarin is still one of the most frequently prescribed cardiovascular drugs. The recently conducted Active W study once again established its therapeutic superiority over even a combination of antiplatelet drugs for the prevention of str...

BACKGROUND AND AIM Warfarin is the most frequently prescribed anticoagulant worldwide. However, warfarin therapy is associated with a high risk of bleeding and thromboembolic events because of a large interindividual dose-response variability. We investigated the effect of genetic and non genetic factors on warfarin dosage in a South Italian population in the attempt to setup an algorithm easil...

Warfarin is the most widely used oral anticoagulant in the world for patients with venous thrombosis, pulmonary embolism, chronic atrial fibrillation, and prosthetic heart valves. Approximately 30 genes contribute to therapeutic effects of warfarin, and genetic polymorphisms in these genes may modulate its anticoagulant activity. In contrast to monogenic pharmacogenetic traits, warfarin drug re...

Several genome-wide association studies have been performed on warfarin. For acenocoumarol, the most frequently used coumarin in many countries worldwide, pharmacodynamic influences are expected to be comparable. Pharmacokinetics however might differ. We aimed to confirm known or identify new genetic variants contributing to interindividual variation on stabilized acenocoumarol dosage by a GWAS...

BACKGROUND Algorithms combining both clinical and genetic data have been developed to improve oral anticoagulant therapy. Three polymorphisms in two genes, VKORC1 and CYP2C9, are the main coumarin dose determinants and no additional polymorphisms of any relevant pharmacogenetic importance have been identified. OBJECTIVES To identify new genetic variations in VKORC1 with relevance for oral ant...

Background and Aims: Warfarin is an anticoagulant agent used for many years in treating various clinical conditions such as thromboembolisms in cardiovascular disease. Some patients require different doses of warfarin to reach the therapeutic international normalized ratio ratio. These patients have specific demographic characteristics. Genetic polymorphisms in specific genes have been reported...

Patients require different warfarin dosages to achieve the target therapeutic anticoagulation. The variability is largely genetically determined, and it can be only partly explained by genetic variability in the cytochrome CYP2C9 locus. In 147 patients followed from the start of anticoagulation with warfarin, we have investigated whether VKORC1 gene mutations have affected doses of drug prescri...