Coumadin / warfarin is an anticoagulant medication used to prevent and treat blood clots like deep vein thrombosis (DVT) and pulmonary embolism (PE). The PT-INR test measures the effect of warfarin (Coumadin). DESCRIPTION. COUMADIN (warfarin sodium) tablets and COUMADIN (warfarin sodium) for injection contain warfarin sodium, an anticoagulant that acts by inhibiting vitamin K⌈dependent coagulation factors. Venous thromboembolism (VTE) is a disorder that includes deep vein thrombosis and pulmonary embolism. A deep vein thrombosis (DVT) occurs when a blood clot forms in a deep vein, usually in the lower leg, thigh, or pelvis. Learn how UpToDate can help you. Select the option that best describes you Check with your Doctor, he will know what you can take, but don't take aleve or advil on warfarin. On the day of your blood test… In the morning: have your blood test. In the afternoon: ring your doctor or nurse for the result. They will tell you what dose to take until your next blood test. I had another PE but I was skipping days on my Xarelto. It's so expensive and I can't tolerate warfarin. I feel I have permanent damage from my PEs. WARNINGS: Warfarin can cause very serious (possibly fatal) bleeding. This is more likely to occur when you first start taking this medication or if you take too much warfarin. Blood Clots in the Lung (Pulmonary Embolism - PE) at 28 Years Old: Bonnie's Story Bonnie Jacobs December, 2008 I'm talking about this because I want everyone to know the risks and symptoms. Leafy foods high in vitamin K, like spinach, can affect how well warfarin works.