Special Alerts:

[Posted 08/16/2007] FDA approved updated labeling to include pharmacogenomics information to the CLINICAL PHARMACOLOGY, PRECAUTIONS, and DOSAGE AND ADMINISTRATION sections of the prescribing information for the widely used blood-thinning drug, warfarin (Coumadin). This new information explains that people’s genetic makeup may influence how they respond to the drug. Specifically, people with variations in two genes may need lower warfarin doses than people without these genetic variations. The two genes are called CYP2C9 and VKORC1. The CYP2C9 gene is involved in the breakdown (metabolism) of warfarin and the VKORC1 gene helps regulate the ability of warfarin to prevent blood from clotting.

The dosage and administration of warfarin must be individualized for each patient according to the particular patient’s prothrombin time (PT) / International Normalized Ratio (INR) response to the drug. The specific dose recommendations are described in the warfarin product labeling, along with the new information regarding the impact of genetic information upon the initial dose and the response to warfarin. Ongoing warfarin therapy should be guided by continued INR monitoring. For more information visit the FDA website at: [Web].

[Posted 10/06/2006] FDA and Bristol-Myers Squibb notified pharmacists and physicians of revisions to the labeling for warfarin (Coumadin), to include a new patient Medication Guide as well as a reorganization and highlighting of the current safety information to better inform providers and patients.

The FDA regulation 21CFR 208 requires a Medication Guide to be provided with each prescription that is dispensed for products that FDA determines pose a serious and significant public health concern. Information about all currently approved Medication Guides is available at: [Web]. For more information visit the FDA website at: [Web], and [Web].