Chinese patients are reportedly more sensitive than Caucasians to the anticoagulant effect of warfarin. We examined warfarin dose requirements and their determinants in 151 Chinese out-patients on stable maintenance dose of warfarin with international normalized ratio of 2 to 2.5. Mean daily warfarin requirement was 3.3 +/- 1.4 mg, much lower than reported doses in Caucasian patients. The most ...

Multiple factors have been shown to influence the pharmacokinetics, pharmacodynamics and, hence, dosage requirements of the oral anticoagulant, warfarin (1-3). The relationship between patient age in the adult population and warfarin maintenance dose is controversial. Several studies (4-6) have found a significant inverse correlation between age and dose, and it has been reported (5) that the e...

Background: Warfarin is a common anticoagulant drug that has a narrow therapeutic index; higher dose causes excessive bleeding and lower dose leads to cerebrovascular clotting and stroke in patients. Genetic factors that have been associated with warfarin response are the genes of cytochrome P450 2C9 (CYP2C9), which metabolize the more active S-enantiomer of warfarin, and vitamin K epoxide redu...

Patients using warfarin for oral anticoagulant therapy need to be frequently monitored because of warfarin's narrow therapeutic range and the large variation in dose requirements among patients. Patients receiving the wrong dose have an increased risk of bleeding or thromboembolic events. The required dose is influenced by environmental factors, such as gender, age, diet and concomitant medicat...

background: warfarin is a common anticoagulant drug that has a narrow therapeutic index; higher dose causes excessive bleeding and lower dose leads to cerebrovascular clotting and stroke in patients. genetic factors that have been associated with warfarin response are the genes of cytochrome p450 2c9 (cyp2c9), which metabolize the more active s-enantiomer of warfarin, and vitamin k epoxide redu...

Warfarin induction is accomplished by titrating dosage to coagulation test results. Algorithms can guide this process but not identify the starting dose. We hypothesized that an initial warfarin dose approximating the maintenance value would safely enhance rapidity of induction. In a randomized trial we compared a fixed-dose to a maintenance-dose strategy for beginning warfarin therapy. To pred...

BACKGROUND To determine the contribution of cytochrome P4502C9 (CYP2C9), vitamin K epoxide reductase (VKORC1) and factor VII genotypes, age, body mass index (BMI), international normalized ratio (INR) and other individual patient characteristics on warfarin dose requirements in an adult Turkish population. METHODS Blood samples were collected from 101 Turkish patients. Genetic analyses for CY...

BACKGROUND In patients with kidney impairment, warfarin, a drug metabolized primarily by the cytochrome P-450 system, is initiated at similar doses and managed similarly as in the general medical population. Unfortunately, few data exist to guide dose adjustment in patients with decreased kidney function. Here, we determine the degree of warfarin dose reduction associated with kidney impairment...

BACKGROUND The management of warfarin therapy is complicated by a wide variation among patients in drug response. Variants in the gene encoding vitamin K epoxide reductase complex 1 (VKORC1) may affect the response to warfarin. METHODS We conducted a retrospective study of European-American patients receiving long-term warfarin maintenance therapy. Multiple linear-regression analysis was used...