WARNING

Warfarin may cause severe bleeding that can be life-threatening and even cause death. Tell your doctor if you have or have ever had a blood or bleeding disorder; bleeding problems, especially in your stomach or your esophagus (tube from the throat to the stomach), intestines, urinary tract or bladder, or lungs; high blood pressure; heart attack; angina (chest pain or pressure); heart disease; pericarditis (swelling of the lining (sac) around the heart); endocarditis (infection of one or more heart valves); a stroke or ministroke; aneurysm (weakening or tearing of an artery or vein); anemia (low number of red blood cells in the blood); cancer; chronic diarrhea; or kidney, or liver disease. Also tell your doctor if you fall often or have had a recent serious injury or surgery. Bleeding is more likely during warfarin treatment for people over 65 years of age, and it is also more likely during the first month of warfarin treatment. Bleeding is also more likely to occur for people who take high doses of warfarin, or take this medication for a long time. The risk for bleeding while taking warfarin is also higher for people participating in an activity or sport that may result in serious injury. Tell your doctor and pharmacist if you are taking or plan to take any prescription or nonprescription medications, vitamins, nutritional supplements, and herbal or botanical products (See SPECIAL PRECAUTIONS), as some of these products may increase the risk for bleeding while you are taking warfarin. If you experience any of the following symptoms, call your doctor immediately: pain, swelling, or discomfort, bleeding from a cut that does not stop in the usual amount of time, nosebleeds or bleeding from your gums, coughing up or vomiting blood or material that looks like coffee grounds, unusual bleeding or bruising, increased menstrual flow or vaginal bleeding, pink, red, or dark brown urine, red or tarry black bowel movements, headache, dizziness, or weakness. Some people may respond differently to warfarin based on their heredity or genetic make-up. Your doctor may order a blood test to help find the dose of warfarin that is best for you. Warfarin prevents blood from clotting so it may take longer than usual for you to stop bleeding if you are cut or injured. Avoid activities or sports that have a high risk of causing injury. Call your doctor if bleeding is unusual or if you fall and get hurt, especially if you hit your head. Keep all appointments with your doctor and the laboratory. Your doctor will order a blood test (PT [prothrombin test] reported as INR [international normalized ratio] value) regularly to check your body’s response to warfarin. If your doctor tells you to stop taking warfarin, the effects of this medication may last for 2 to 5 days after you stop taking it. Your doctor or pharmacist will give you the manufacturer’s patient information sheet (Medication Guide) when you begin treatment with warfarin and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (http://www.fda.gov/downloads/Drugs/DrugSafety/ucm088578.pdf) or the manufacturer’s website to obtain the Medication Guide. Talk to your doctor about the risk(s) of taking warfarin.

Why is this medication prescribed?

Warfarin is used to prevent blood clots from forming or growing larger in your blood and blood vessels. It is prescribed for people with certain types of irregular heartbeat, people with prosthetic (replacement or mechanical) heart valves, and people who have suffered a heart attack. Warfarin is also used to treat or prevent venous thrombosis (swelling and blood clot in a vein) and pulmonary embolism (a blood clot in the lung). Warfarin is in a class of medications called anticoagulants (‘blood thinners’). It works by decreasing the clotting ability of the blood.