Clotting factors, anticoagulant rodenticides

Twenty to 24 million prescriptions of Coumadin were dispensed in the United States during 2003-2005. Coumadin is an anticoagulant that acts by preventing the synthesis of active vitamin K, a necessary cofactor for synthesizing active clotting factors. Thus, preventing the synthesis of active vitamin K indirectly inhibits the formation of active clotting factors, notably factor II (prothrombin), VII, IX, and X in the liver. Ironically, coumarins, of which Coumadin is a member, are also used as rodenticides. 

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