Warfarin (Coumadin® and Jantoven®) is an anticoagulant medication or “blood thinner” you take to prevent and treat blood clots that can lead to a stroke or heart attack. Warfarin, sold under the brand name Coumadin among others, is used as an anticoagulant medication. [11][8] It is commonly used to prevent deep vein thrombosis and pulmonary embolism, and to protect against stroke in people who have atrial fibrillation, valvular heart disease, or artificial heart valves. [11] Warfarin (brand names Coumadin and Jantoven) is a prescription medication used to prevent harmful blood clots from forming or growing larger. Beneficial blood clots help control bleeding, while harmful clots can block blood flow, potentially causing serious conditions such as heart attacks, strokes, deep vein thrombosis or pulmonary embolism. Coumadin (Warfarin Sodium) may treat, side effects, dosage, drug interactions, warnings, patient labeling, reviews, and related medications including drug comparison and health resources. While COUMADIN is contraindicated during pregnancy, the potential benefits of using COUMADIN may outweigh the risks for pregnant women with mechanical heart valves at high risk of. What is Coumadin? Coumadin is prescription medicine used to treat blood clots and to lower the chance of blood clots forming in your body. Blood clots can cause a stroke, heart attack, or other serious conditions if they form in the legs or lungs. Coumadin is used to prevent heart attacks, strokes, and blood clots in veins and arteries. Learn about side effects, interactions and indications. Warfarin is used to treat or prevent blood clots in veins or arteries, which can reduce the risk of stroke, heart attack, or other serious conditions. Warfarin may also be used for purposes not listed in this medication guide. Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of food, alcohol, or tobacco. Common Brand Name (s): Coumadin, Jantoven Common Generic Name (s): warfarin, warfarin Na, warfarin sodium Pronunciation: JAN-to-ven, WAR-far-in Drug Classes: anticoagulant, vitamin K antagonist.