At a Glance
Why Get Tested?
To determine whether you have CYP2C9 and/or VKORC1 genetic variations and are likely to need lower, or less commonly, higher than average doses of the anticoagulant drug warfarin
When to Get Tested?
A health practitioner might order this test prior to prescribing warfarin for you if there is a history of warfarin resistance in your family, or more commonly, a health practitioner may sometimes order it when you are being treated with warfarin and have had bleeding or clotting episodes or difficulties in achieving a therapeutic dose of warfarin as determined by blood monitoring.
A blood sample taken from a vein in your arm
Test Preparation Needed?