Genotype-Guided Anticoagulant Selection

Warfarin (an anticoagulant used for thromboembolic disease prophylaxis) is difficult to correctly dose due to its narrow therapeutic index that can cause bleeding risk and individual variability in patient response. Achieving safe and effective warfarin dosing is an urgent concern for clinicians.

The CYP2C9 gene and enzyme influence warfarin metabolism; VKORC1 influences pharmacodynamic response in expression of the enzymatic target of warfarin. Patients who carry CYP2C9*2 or *3 alleles may require lower warfarin doses due to slower metabolism compared to “wild-type” allele carriers. Patients who carry the VKORC1A haplotype may require lower warfarin doses due to lesser mRNA expression and resultant protein formation for VKORC1.