Major Step for Personalized Medicine: Warfarin Sensitivity DNA Test Required By FDA

Implications: The FDA has announced changes in the Warfarin label, recommending that a lower initial Warfarin dose should be considered for patients with certain genetic variations. Warfarin (Coumadin) is a commonly prescribed blood thinner with an exceptionally narrow safe-dosage range that varies dramatically from patient to patient. I think this label modification is one step closer to personalized medicine. Based on modern science and pharmacogenomics (the science that predicts a response to drugs based upon a person's genetic makeup) we can give the right drug in the right dose for the right patient. Overall as a pharmacist & pharmaceutical consultant I think, this labeling change highlights the opportunity to use genetic tests to improve initial estimate of a reasonable Warfarin dose for individual patients.

Analysis:  

The FDA has announced important changes in the Warfarin label, recommending that a lower initial Warfarin dose should be considered for patients with certain genetic variations. These labeling updates are based on an analysis of recent studies that found people respond to the drug differently based, in part, on whether they have variations of certain genes. Warfarin (Coumadin) is a commonly prescribed blood thinner with an exceptionally narrow safe-dosage range that varies dramatically from patient to patient. Warfarin is the second most common drug – after insulin –implicated in emergency room visits for adverse drug events. Historically, determining the correct dose often took multiple clinical visits and blood tests over several weeks or months. Until the correct dosing was established, patients were vulnerable to potentially deadly clotting events such as stroke, and side effects such as hemorrhages, excessive bruising or internal bleeding.

I think this label modification is one step closer to personalized medicine. Based on modern science and pharmacogenomics (the science that predicts a response to drugs based upon a person's genetic makeup) we can give the right drug in the right dose for the right patient. I strongly think that this will further enhance the safety and effectiveness of Warfarin.

Overall as a pharmacist & pharmaceutical consultant I think, this labeling change highlights the opportunity to use genetic tests to improve initial estimate of a reasonable Warfarin dose for individual patients. I also think that genetic testing may help optimize the use of Warfarin and lower the risk of bleeding complications from the drug.