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Drugs, Devices & Supplements

Coumadin* (Anticoagulant)

What is Coumadin?

Coumadin (crystalline warfarin sodium) is a brand of anticoagulant medication. "Anti" means against and "coagulant" means causing blood clotting. Coumadin controls the way blood clots inside your blood vessels.

How does Coumadin work?

Coumadin helps your body control how fast your blood clots. It helps prevent clots from forming inside your blood vessels and heart. If you already have a blood clot, Coumadin may prevent the clot from getting larger. Coumadin does not dissolve a blood clot; however, the clot may dissolve on its own.

How do I take the medication?

Coumadin is taken as a pill each day. You will need to get regular blood tests to tell how well the medication is working. The test results help the doctor decide the dose of Coumadin that will keep a balance between clotting and bleeding. Your doctor will use the results to make changes in the dose of medication. Follow your doctor's instructions for getting blood tests and adjusting your daily Coumadin dose.

Precautions when taking Coumadin


Many medications and vitamins can affect how Coumadin works, including:

  • Some prescription medications
  • Non-prescription medications such acetaminophen, aspirin, ibuprofen, nonsteroidal anti-inflammatory drugs (NSAIDS), cold, and cough medicines
  • Antacids, laxatives or other medications for pain or discomfort
  • Vitamins containing vitamin K or large amounts of vitamin E or C

Do not stop or start any medications without first talking to your doctor.

Pregnancy, surgery, and dental work

If you are a woman taking Coumadin and planning to become pregnant, talk with your doctor about the possible risks and ways to reduce those risks. Tell your doctor right away if you become pregnant. Before receiving treatment, tell all of your doctors and dentists you are taking Coumadin.

Diet and exercise

Large amounts of foods high in vitamin K may change the way Coumadin works. Limit foods high in vitamin K to a ½-cup, cooked serving or one 3-ounce, raw serving per day. Foods rich in vitamin K include green tea, beef liver, soy oil, tofu, broccoli, brussel sprouts, cabbage, cauliflower, chick peas, kale, lettuce, turnip greens, seaweed, and spinach.

Check with your doctor before starting any exercise or sports program. Talk with your doctor if you are planning any major diet changes. Alcoholic beverages can also change the way Coumadin works. Ask your doctor about the amount of alcoholic beverages you may drink.

Daily activities

Be careful when using razors. Use an electric razor or hair-removing creams to lessen the chance of cuts. Use a soft toothbrush. Brush and floss gently to prevent bleeding from the gums.

Illness and emergencies

Keep your doctor's phone number close by in case of an emergency. Call your doctor if you have any symptoms of illness, such as vomiting, diarrhea, infection or fever. Always carry or wear identification that states you are taking Coumadin. Falls that cause bruising (bleeding under the skin) and cuts from sharp objects are more serious when you are taking Coumadin. Call your doctor if you have any injuries that involve falls or blows to the body or head.

If you cut yourself. . .

If the cut is small, apply constant pressure over the cut until the bleeding stops (this may take up to 10 minutes). If the bleeding doesn't stop, continue to apply pressure and go to the nearest emergency room.

If the cut is large, apply constant pressure and get help immediately.

Call your doctor if you notice any of the following signs of bleeding:
  • Feeling tired or looking pale (sign of anemia)
  • Bleeding from cuts that won't stop after applying pressure for 10 minutes
  • Bleeding from the nose, gums or ears
  • Menstrual bleeding that is heavier or longer than normal
  • Reddish or rusty colored urine
  • Bowel movements that look bright red, black or tarry
  • Bruises that appear without reason or become swollen; purplish spots on your skin
  • Vomiting blood (which may look like coffee grounds)
  • Coughing up blood
  • Unusual hemorrhoidal bleeding
  • Unusual pain or swelling, especially in the joints
  • Unusual headache
  • Stomach or abdominal pain

If you have any of these signs, contact your doctor right away.

*References in this document to the brand name Coumadin are made solely for the ease of patient identification. This reference does not constitute an expressed or implied endorsement of this brand.

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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition.This document was last reviewed on: 2/15/2010…#4066