Sample blister packs of the blood thinner Coumadin distributed to doctors throughout the United States are being recalled by the Food and Drug Administration (FDA) as a precautionary measure because some of the tablets, over time, may not meet the specification for isopropanol. Isopropanol is used to maintain the active ingredient, Coumadin, in the crystalline state, and could affect the therapeutic levels of the active ingredient.

Coumadin is prescribed to treat or prevent blood clots. A decrease of active ingredient may increase the risk of blood clots, which could lead to heart attacks or strokes. An increase of active ingredient increases the risk of bleeding. The recall only affects some lots of physician sample Coumadin 1 mg tablet blister packs and does not involve any Coumadin supplied in bottles nor any other strengths and dosage forms of the products. Patients who have physician sample blister packs that fall under the recall should contact their physicians to ensure that their anticoagulation therapy is not interrupted.

The following lot numers are included in the recall: Lot# 9A48931A, 9A48931B, 9A48931C, expiration January 2012; HUD Blister Pack: Lot# 8F34006B, 8K44272A, 8K46168A, 9F44437A and 9K58012B with expiry dates between June 2011 and November 2012.

Bristol-Myers Squibb, makers of Coumadin, has not received any reports of adverse events related to this issue. The company has issued recall communications to all physicians and other customers who may have received recalled lots of Coumadin.

Any adverse events with this or any other product should be reported to the FDA’s MedWatch Adverse Event Reporting Program at www.FDA.gov/MedWatch.