According to the Institute of Traditional Medicine website, warfarin has been used as a rodenticide since shortly after World War II. Karl Paul Link at the Wisconsin Alumni Research Foundation (WARF), associated with the University of Wisconsin, discovered coumarin, a substance that prevents blood from clotting, which is the basis for both the thinner marketed under the name Coumadin and warfarin. The original name warfarin is a tribute to the Wisconsin alumni group that funded the initial research and held the original patents.
Warfarin was developed from spoiled sweet clover hay. It was known that in some cases spoiled hay lead to livestock deaths due to hemorrhaging. Researchers at the University of Wisconsin attempted to breed a sweet clover plant that would not cause bleeding in livestock that consumed any spoiled feed made from the plant. This research isolated dicoumarol that was patented as an anti-coagulant in 1941. It was refined and synthesized as warfarin in 1948.
Warfarin was initially used as a rodenticide and rapidly became the most widely used rodent poison in the world. According to the Institute of Traditional Medicine, a 1951 attempted suicide incident where an individual consumed a large dose of warfarin but recovered lead to research concerning the use of warfarin in humans. The first human uses of warfarin, called Coumadin when used in humans, were in 1954 when President Dwight Eisenhower was treated with it after a 1955 heart attack.
How it Works
Warfarin disrupts the action of vitamin K, a substance that promotes blood clotting, as it works in the body. It also disrupts a number of proteins produced by the liver that also play a part in blood clotting. In rodents this lack of blood clotting causes fatal internal hemorrhaging. In humans, with controlled doses and blood testing, the reduction in the blood clotting function reduces the possibility of some medical conditions.
Coumadin is commonly used in patients at risk for ailments caused by excessive blood clotting. These include strokes, heart attacks and blood clots. It is usually discontinued temporarily prior to any surgery out of fear of uncontrolled bleeding.
Coumadin is only available by a doctor’s prescription and is heavily regulated. Blood tests will be performed to determine the “pro time” or prothrombin time. This test determines the bloods tendency to clot and is stated in seconds. Dosages are adjusted to achieve the ideal pro time. Frequent tests are key to a successful treatment protocol.