ClotCare: Blood Clots, Stroke, Heart Attack
Thursday, October 19, 2017
Home   |   DVT/PE   |   Blood Clots   |   Coumadin/Warfarin   |   New Patients   |   Self Testing   |   Email List   |   Donate

Pick a Topic:

Find info on a:

We subscribe to the HONcode principles of the HON Foundation. Click to verify.
ClotCare complies with the HONcode standard for trustworthy health
information:
verify here.

ClotCare is a member of the Coalition to Prevent Deep Vein Thrombosis (DVT Coalition)  ClotCare is a member organization of the Coalition to Prevent Deep Vein Thrombosis. Click here to learn more about the Coalition to Prevent Deep Vein Thrombosis and DVT Awareness Month, which is held each March.

Genetic Variation in Warfarin Metabolism

Ann K. Wittkowsky, Pharm.D., CACP
September 2004

Review: Joffe HV, Xu R, Johnson FB, Longtine J, Kucher N, Goldhaber SZ. Warfarin dosing and cytochrome P450 2C9 polymorphisms. Thromb Haemost. 2004 Jun;91(6):1123-8.

Variant genetic expression of cytochrome p450 2C9 is associated with significant reductions the metabolism of S-warfarin. Previous studies have confirmed that patients with CYP2C9 polymorphisms have decreased warfarin dosing requirements. Other studies have suggested a higher incidence of bleeding complications in patients with CUP2C9 polymorphisms.

This paper found that after excluding other reasons for low warfarin dosing requirements, 100% of patients who required < 1.5mg/day of warfarin to reach a goal INR of 2-3 had CYP2C9 polymorphisms CYP2C9*2 or CYP2C9*3. Over an average of 26 months of follow-up, these patients were more likely to experience at least 1 asymptomatic INR > 6.0. However, these patients were no more likely to experience bleeding complications than patients with mean warfarin dosing requirements of 4-6mg/day or > 10mg/day, in whom CYP2C9 polymorphisms were less common. The authors suggested that the close warfarin monitoring provided by the Anticoagulation Service that managed warfarin in these patients may have limited the risk of bleeding complications.

Ask a question about blood clots or anticoagulant medications Have questions? Ask ClotCare. Send questions by email to webmaster@clotcare.org.

ClotCare is a 501(c)(3) non-profit organization generously supported by your tax-deductible donations and grants from our industry supporters.

Blood Clot Activities Calendar

New Postings:

World Thrombosis Day - Oct. 13, 2017

Rivaroxaban or Warfarin in Stable Coronary Artery Disease – Should the COMPASS Study Lead Us Back to the Future?

Click here to view full list of new postings
ClotCare Home | New Postings | Patient Postings | Clinician Postings | Join Our Email List | Useful Web Links
CE Opportunities | Training Programs | DVT & PE Stories | Editorial Board | Financial Support
About ClotCare | DVT Coalition | Donate to ClotCare | Contact Us
Key topics discussed on ClotCare include: Blood Clots | Deep Vein Thrombosis (DVT) | Pulmonary Embolism (PE) | Atrial Fibrillation (A. Fib or AF) | Heart Attack | Stroke | Transient Ischemic Attack (TIA) | Mini Stroke | Bleeding Complications | Vascular Surgery | Surgical Blood Clot Removal | Warfarin | Coumadin | Lovenox | Low Molecular Weight Heparin (LMWH) | Heparin | Anticoagulants | Plavix | Aspirin | Antiplatelets | Blood Thinners
Copyright 2000-2014 by ClotCare. All rights reserved.
Terms, Conditions, & Privacy | Image Copyright Information
19260 Stone Oak Parkway, Suite 101 | San Antonio, TX 78258 | 210-495-4335
Send comments to webmaster@clotcare.org.
Thursday, October 19, 2017