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    Coumadin® (warfarin)

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    What is Coumadin® (warfarin)?


    Your doctor has started you on the medication Coumadin (generic name: warfarin). Coumadin is a "blood thinner" that helps prevent blood clots from forming in the blood vessels, the heart and the lungs. It also helps your blood flow more easily.

    Patients who are on Coumadin must be watched closely. Too much Coumadin can cause bleeding, while too little can allow blood clots to form.

    Take this medication exactly as directed by your doctor after you leave the hospital.

    • Take Coumadin at the same time each day, usually in the evening

    • Go for blood tests as directed

    • Never skip a dose

    • Never take a double dose

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    What Blood Test Do I Need?


    You will need to have your blood tested regularly. The most common blood test is called a PT/INR. This blood test measures how long it takes for your blood to clot. Your PT/INR result helps your doctor decide the best Coumadin dosage for your medical needs.

    Your Next PT/INR Appointment
    M    T    W    Th    F    ___ / ___ / ___ at ____:____ am/pm

    • Schedule your PT/INR blood test within 3 days after leaving the hospital, or as directed by your doctor/nurse.

    • Call your doctor's office the same day you have your blood test done and ask for the results. Make sure to do this before taking your next dose of Coumadin.

    • Get your PT/INR checked on a regular basis as long as you are taking Coumadin. Your doctor or nurse will inform you when this test needs to be done.
    Call Your Doctor Immediately or Go to the Emergency Room if You Have:

    • Serious bruising for no reason

    • Bleeding that does not stop quickly with direct pressure

    • A serious fall or hit on the head, even if there is no bleeding

    • Red, dark or coffee-colored urine

    • Bowel movements that are red or look like tar

    • Dizziness or weakness

    • Severe pain, such as a headache or stomach ache

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    Medication Precautions with Coumadin


    Always check with your doctor or pharmacist before taking any new medication, including over-the-counter medications, vitamins and herbal supplements (especially those containing vitamin E or vitamin K). Some examples are:

    • Aspirin

    • Plavix® (clopidogrel)

    • Aleve® (naproxen)

    • Advil® (ibuprofen)

    • Motrin® (ibuprofen)

    • Some antibiotics

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    Stay Safe While Taking Coumadin

    • Tell your doctor you are on Coumadin if you are scheduled to have a procedure, test, surgery or dental work.

    • Speak with your doctor about limiting your alcohol intake.

    • Avoid risky contact sports or other activities that increase your chance of bleeding or cause injury. Safe activities include swimming and walking.

    • Do not take Coumadin if you are pregnant or could become pregnant. Tell your doctor if you are pregnant or breastfeeding.

    • Never stop taking Coumadin without first speaking to your doctor.

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    Diet for Coumadin Users

    • A sudden change in the level of vitamin K in your diet can affect the way Coumadin works in your body. It is important to be consistent and to not make sudden changes in your dietary intake of foods high in vitamin K. Some of these foods include:
      • spinach

      • turnip greens

      • broccoli

      • cabbage

      • cauliflower

      • chickpeas (garbanzo beans)

      • soybean oil

      • lentils

      • liver

      • seaweed
    • Avoid or limit your intake of green tea and teas with chamomile or cinnamon.
    Note: This handout is also available in Chinese, Russian, and Spanish.


    Developed by: Jill Ley, RN, MS, CNS, Department of Outcomes Management.

    Reviewed by: Gary Louie, PharmD, Maile Shubin, RD, CNSC, Anita Zefo, RD, Robert Rodvien, MD, FACP, Jeffrey Tayag, NP.

    Produced by: The Center for Patient and Community Education at California Pacific Medical Center. Last updated: 5/09

    References: Lexi-Comp Inc. (1978-2004). Coumadin (warfarin). Retrieved November 14, 2004 from www.crlonline.com/crlonline. USDA National Nutrient Database for Standard Reference, Release 16. Retrieved February 4, 2009 from www.nal.usda.gov/fnic/foodcomp/Data/SR16/wtrank/sr16w430.pdf


    Funded by: A generous donation from the Mr. and Mrs. Arthur A. Ciocca Foundation.

    Note: This information is not meant to replace any information or personal medical advice which you get directly from your doctor(s). If you have any questions about this information, such as the risks or benefits of the treatment listed, please ask your doctor(s).

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