Study published in NEJM reports that variations in VKORC1 influence the drug’s effect at the earliest stage.
The gene VKORC1 plays a role in determining a patient’s initial sensitivity to the blood-thinning drug warfarin, scientists from Vanderbilt University School of Medicine report.
Their findings confirm earlier research that the two genes, VKORC1 and CYP2C9, help predict how well a patient responds to warfarin. The new results of the study indicate that although both genes significantly influence response to the drug after the first two weeks of therapy, only variations of VKORC1 predict response within the first week of therapy.
Researchers assessed CYP2C9 genotypes (CYP2C9 *1, *2, and *3) and VKORC1 haplotypes (designated A and nonA) in 297 patients starting warfarin therapy. They compared the participants’ clinical characteristics and response to therapy, determined by international normalized ratio and bleeding events.
The study is published in the March 6, issue of the New England Journal of Medicine.
