DNA Direct: Your Genes in Context

Login

Register as a New User

forgot your password?
view privacy policy

Problems accessing your account?
Email support@dnadirect.com or call us at 1-877-646-0222.

Testing for Drug Response

Related Genetic Tests

Warfarin Response

Includes a personalized report, a letter for your doctor, and toll-free support

Price: $199.00

Order Testing

Pre-test & Post-test Consultation

Our genetic experts can counsel you before and after testing.

Price: $250 per hour

Call to schedule: 1-877-646-0222

Related Genetic Tools

Drug Response Test Finder

Over half of all medications are affected by 3 genes that you can test for: CYP 2D6, 2C9 and 2C19. This tool to see which drugs are affected by these genes.

Start the Tool

WARFARIN RESPONSE TESTING

What Else Affects Warfarin Response?

In addition to your genetic make-up, there are many other factors that influence how you may respond to warfarin. These include:

Age: The required warfarin dose usually decreases as you get older.
Height and Weight: A higher warfarin dose is generally needed if you are taller and/or weigh more.
Ethnicity: Ancestry has long been recognized to play an important role in how much warfarin is needed. In general, people of Asian descent require lower doses than Caucasians, and those with African American heritage require higher doses. This may be explained by shared genetic variations.
Diet: Warfarin works by inhibiting vitamin K. People who consume large amounts of vitamin K (either through foods or supplements) may need higher warfarin doses.
Other Medications, Herbs, or Supplements: Many prescription and over-the-counter medications are known to interact with warfarin. It is extremely important that the doctor prescribing warfarin is aware of all the medications, herbs, and supplements you use, even those prescribed by other doctors.
Other Health Conditions: Some diseases affect how our bodies respond to medications – particularly diseases of the thyroid, liver or kidney where much of drug processing occurs.

All of this information should be taken into account when determining your optimal warfarin dose. When genetic information is combined with these factors, about 60% of the variability in individual response can be explained.

Next Article: 2C9 and Other Drugs