Based in part on NIGMS-supported research on how gene variation affects a person’s response to medicines, the U.S. Food and Drug Administration has modified the prescribing instructions for warfarin (Coumadin), a widely used blood thinner.
Millions of Americans take warfarin to prevent clots after a heart attack, stroke, or major surgery.
Finding the optimal dose for each patient is tricky because it depends on many factors, including age, weight, diet, and genetic makeup.
Getting it wrong can be fatal. The new information describes variations in two genes—CYP2C9 and VKORC1—that affect the correct dose.
In the future, tests of these genes may help doctors determine a more accurate starting dose for each patient and reduce complications.