If you are taking coumaden, it is necessary to monitor your intake of foods that are rich in vitamin K. Consuming too much vitamin K can counteract the effects of coumaden, cancelling it's stroke prevention action. Warfarin suppresses your body's normal ability to make blood clots. This is good, to prevent an unwanted blood clot on lung or legs -- or blood clots in brain -- which can cause a heart attack or stroke. Learn about Coumadin (Warfarin Sodium) may treat, uses, dosage, side effects, drug interactions, warnings, patient labeling, reviews, and related medications. by Vin Kutty on April 22, 2010 215 Comments. OK – you tried fish oil because it’s good for you. Now you’re experiencing some minor fish oil side effects. Most people take Plavix once a day. It's a good idea to take this drug with food and lots of water in order to reduce the side effects. Never stop taking Plavix without talking to your doctor. Coumadin ® is indicated for: • Prophylaxis and treatment of venous thrombosis and its extension, pulmonary embolism (PE). • Prophylaxis and treatment of thromboembolic complications associated with atrial fibrillation (AF) and/or cardiac valve replacement. What are some side effects that I need to call my doctor about right away? WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Warfarin oral tablet is available as both a generic and brand-name drug. Brand name: Coumadin, Jantoven. Warfarin comes only as a tablet you take by mouth. Welcome. This site has been created to help you understand COUMADIN. We encourage you to learn all you can about taking COUMADIN and to use the tools we've provided to work with your healthcare provider to manage your treatment. XARELTO ® may cause serious side effects, including: Increased risk of blood clots if you stop taking XARELTO ®. People with atrial fibrillation (an irregular heart beat) that is not caused by a heart valve problem (nonvalvular) are at an increased risk of forming a blood clot in the heart, which can travel to the brain, causing a stroke, or.