Do you know someone taking the blood thinner warfarin to prevent and treat blood clots?

Sharing this information may avoid hospitalization.

Approximately 2 million people in the United States are prescribed the blood thinner warfarin each year to prevent and treat blood clots. Prescribing the right dose of warfarin is extremely difficult for doctors to do: Too high a dose of warfarin can lead to a major bleeding episode; too little can result in blood clots that can cause strokes and other serious conditions. However, new research shows that giving a patient a genetic test can help doctors better determine the correct dosage of warfarin and can reduce the chance that the patient will end up in the hospital by 30%.

You may wonder what a genetic test has to do with a commonly used blood thinner. The answer is that genetic variations affect how people respond to certain medications. In the case of warfarin, genes determine how well the enzymes CYP2C9 and VKORC1 will inactivate the drug and how sensitive you will be to the medication. If you have genetic variations that speed up the inactivation of warfarin or make you less sensitive to it, you will need a higher dose of the drug, and if you have genetic variations that slow the inactivation of warfarin or make you overly sensitive, you’ll need a smaller dose. Just a small change in the dose can be the difference between the drug being effective or ineffective, safe or dangerous.

Despite the fact that warfarin has been the most widely used blood thinner for over a half-century, it ranks among the leading medications in drug-related emergency room visits and drug-related deaths. And while there is now a simple genetic test that can help prevent these terrible consequences, and requires only the cells that can be scraped from the inside of your cheek with a swab, the use of these tests is still very low. We encourage you to share this information with friends or family members who may be using warfarin so they can talk to their physicians about this genetic test. A swab of the cheek can ensure that their medication is prescribed at the proper dosage, which ultimately helps them avoid a hospitalization.