Abstract
Polymorphisms in CYP2C9 and VKORC1 have been shown to be associated with warfarin dose requirements and could be used to predict warfarin dose. We conducted a prospective study in which warfarin dose was prescribed based on CYP2C9 and VKORC1 polymorphisms in 108 Han-Chinese patients without prior warfarin treatments. Using the genotype-based dosing, 83% of patients reached stable, therapeutic international normalized ratio (INR) within 2 weeks of treatment initiation and none of the patients developed clinical bleeding or thromboembolic event. Ten percent (11) of patients with INR >4 and no clinical bleeding were detected during this study. At 12 weeks, 69% of the patients' maintenance doses matched the prediction. Dosing algorithms incorporating genetic factors, age, and body surface area were developed, which could explain up to 62% of the total variation (R2 of 0.62). This study demonstrated that pharmacogenetics-based dosing could improve time to stable, therapeutic INR, reduce adverse events, and achieve high sensitivity.
Original language | English |
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Pages (from-to) | 83-89 |
Number of pages | 7 |
Journal | Clinical Pharmacology and Therapeutics |
Volume | 84 |
Issue number | 1 |
DOIs | |
State | Published - 07 2008 |