Coumadin, also called warfarin, is a prescription medication blood thinner, or anticoagulant. Coumadin is prescribed to people with prosthetic heart valves, certain irregular heartbeats, and to those who have had a heart attack. It is also prescribed to people who have leg vein clots or lung clots. In all of these cases, the role of Coumadin is to treat or prevent heart attack, stroke and blood clots.
How Vitamin K Works
In order to understand how Coumadin works as a blood thinner, it is best first to take a look at how vitamin K works. In the liver, proteins known as clotting factors are responsible for forming clots and stopping bleeding. These proteins are unable to function without the help of vitamin K. Vitamin K is taken up by the liver where it chemically activates the clotting factors, allowing them to continue in the process of forming a clot.
How Coumadin Works
Coumadin blocks the action of vitamin K essentially by competing for space in the liver. Since both Coumadin and vitamin K use the same uptake sites on the liver, the presence of Coumadin ends up decreasing the absorption of vitamin K, ultimately inhibiting the clotting process.
Foods Rich in Vitamin K Can Block the Action of Coumadin
People taking Coumadin are often warned to avoid eating large amounts foods that are particularly high in vitamin K, since these foods can interfere with Coumadin's ability to thin the blood. Foods rich vitamin K include leafy, green vegetables such as parsley, broccoli or spinach, soybean oil and canola oil.
Vitamin K Can Be Used to Treat Coumadin Overdose
Although most patients taking Coumadin should avoid foods rich in vitamin K, it is easy to imagine how this vitamin could be useful in cases of a Coumadin overdose. Clinical overdosage with Coumadin can result in prolonged bleeding and can be quite serious. Part of the management of Coumadin overdosing involves administration of vitamin K.
