Coumadin

Generic name: Warfarin sodium

What is Coumadin?

Coumadin is an anticoagulant (blood thinner) used to reduce clots from forming in the blood. It is also used to prevent and/or treat blood clots in the legs and lungs associated with an irregular, rapid heartbeat or those associated with heart-valve replacement. It may also be used after a heart attack to lower the risk of death, another heart attack, stroke, or blood clots moving to other parts of the body.

What is the most important information I should know about Coumadin?

The most serious risks associated with Coumadin are hemorrhage (severe bleeding resulting in the loss of a large amount of blood) in any tissue or organ and, less frequently, the destruction of skin tissue cells (necrosis) or gangrene. The risk of hemorrhage usually depends on the dosage and length of treatment with Coumadin.

Hemorrhage and necrosis have been reported to result in death or permanent disability. Severe necrosis can lead to the removal of damaged tissue or amputation of a limb. Necrosis appears to be associated with blood clots located in the area of tissue damage and usually occurs within a few days of starting Coumadin treatment.

Who should not take Coumadin?

Coumadin should not be used for any condition where the danger of hemorrhage may be greater than the potential benefits of treatment. Unless directed to do so by your doctor, do not take Coumadin if one of the following conditions or situations applies to you: a tendency to hemorrhage; alcoholism; an abnormal blood condition; aneurysm (balloon-like swelling of a blood vessel) in the brain or heart; bleeding tendencies associated with ulceration or bleeding of the stomach, intestines, respiratory tract, or the genital or urinary system; eclampsia (a rare and serious hypertensive disorder that can occur during pregnancy) or preeclampsia; excessive bleeding of brain blood vessels; inflammation, due to bacterial infection of the membrane that lines the inside of the heart; inflammation of the sac that surrounds the heart or an escape of fluid from the heart sac; malignant hypertension (extremely elevated blood pressure that damages the inner linings of blood vessels, the heart, spleen, kidneys, and brain); pregnancy; recent or scheduled surgery of the central nervous system (brain and spinal cord) or eyes; spinal puncture or any procedure that can cause uncontrollable bleeding; threatened miscarriage; or allergy to any of the drug's ingredients.

What should I tell my doctor before I take the first dose of Coumadin?

Tell your doctor about all prescription, over-the-counter, and herbal medication you are taking before beginning treatment with Coumadin. Also, talk to your doctor about your complete medical history, especially if you have an infectious disease or intestinal disorder; a family history blood clotting disorders; an implanted catheter; chronic heart failure; recent or scheduled dental procedures; high blood sugar (diabetes); inflammation of a blood vessel; kidney or liver disease; moderate to severe high blood pressure; moderate to severe kidney or liver dysfunction; a blood disorder called polycythemia vera; surgery or injury that leaves large raw surfaces; or trauma or injury that may result in internal bleeding.

What is the usual dosage?

The information below is based on the dosage guidelines your doctor uses. Depending on your condition and medical history, your doctor may prescribe a different regimen. Do not change the dosage or stop taking your medication without your doctor's approval.

Adults: A common starting dose is 2 to 5 milligrams (mg) per day. Individualized daily dosage adjustments are based on the results of blood tests that determine the amount of time it takes for the blood clotting process to begin.

A long-term dose of 2 to 10 mg per day is satisfactory for most people. The duration of treatment will be determined by your doctor.

Elderly: Low starting and long-term doses are recommended for older people.

Coumadin is not approved for use in patients <18 years.

How should I take Coumadin?

Take Coumadin exactly as prescribed. Your doctor must monitor your condition on a regular basis. Be especially careful to stick to the exact dosage schedule your doctor prescribes. Try to take Coumadin the same time every day.

Carry an identification card that indicates you are taking Coumadin.

What should I avoid while taking Coumadin?

Do not take or discontinue any other medication unless directed to do so by your doctor. Avoid alcohol, salicylates such as aspirin, larger than usual amounts of foods rich in vitamin K (eg, liver, vegetable oil, egg yolks, and green leafy vegetables) that can counteract the effect of Coumadin, or any other drastic change in diet.

Avoid activities and sports that could cause an injury and bleeding.

What are possible food and drug interactions associated with Coumadin?

Coumadin can interact with a wide variety of drugs, both prescription and over-the-counter. Check with your doctor before taking any medication or vitamin product. Be extremely cautious, too, about taking any herbal remedies and supplements. A wide assortment of herbal products, including St. John's wort, coenzyme Q10, bromelain, dan-shen, dong quai, garlic, cranberry products, and gingko biloba, are known to interact with Coumadin or otherwise affect coagulation.

What are the possible side effects of Coumadin?

Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking this drug.

Side effects may include: bleeding (signs and symptoms of bleeding include headache, dizziness, or weakness; bleeding from shaving or other cuts that does not stop; nosebleeds; bleeding of gums when brushing your teeth; throwing up blood; unusual bruising for unknown reasons; red or dark brown urine; red or black color in your stool; more bleeding than usual during your menstrual period or unexpected bleeding from the vagina; unusual pain or swelling.)

Treatment with blood thinners may increase the risk that fatty plaque will break away from the wall of an artery and lodge at another point, causing the blockage of a blood vessel. If you notice any of the following symptoms, contact your doctor immediately: Abdominal pain, abrupt and intense pain in the leg, foot or toes, blood in the urine, bluish mottling of the skin of the legs and hands, foot ulcers, gangrene, high blood pressure, muscle pain, "purple toes syndrome" (see below), rash, or thigh or back pain.

Purple toes syndrome can occur when taking Coumadin, usually 3 to 10 weeks after starting therapy. Symptoms include dark purplish or mottled color that turns white when pressure is applied and fades when you elevate your legs; pain and tenderness; and change in intensity of the color over a period of time. If any of these symptoms develop, notify your doctor immediately.

Can I receive Coumadin if I am pregnant or breastfeeding?

Do not take Coumadin if you are or may become pregnant because it can cause fatal hemorrhage in the developing baby. If you become pregnant while taking Coumadin, inform your doctor immediately. Avoid breastfeeding while you are taking Coumadin.

What should I do if I miss a dose of Coumadin?

If you forget to take a pill, tell your healthcare provider immediately. Take the missed dose as soon as possible on the same day. Do not take 2 doses at the same time.

How should I store Coumadin?

Store at room temperature in a tightly closed container away from light.