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    Warfarin and Other Blood Thinners for Heart Disease

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    How Should I Take It?

    Take your warfarin dose as instructed once a day. Try to take it at the same time every day. A good time to take warfarin is early in the evening (such as between 5 and 6 p.m.). Warfarin can be taken with or without food.

    Do not take a double dose to make up for a missed dose. Also, never change your dose without first discussing the change with your doctor.

    How Should I Store It?

    As with most drugs, store warfarin at room temperature, away from extreme cold, heat, light, or moisture. Bathroom cabinets are usually NOT suitable for storing medications because of the dampness. All medications, including warfarin, should always be kept out of the reach of children and pets.

    What Precautions Should I Take?

    It is important that you follow these precautions when taking warfarin to reduce the risk of side effects and improve the effectiveness of your medication.

    Medications and Dietary Supplements 
    Many medications and dietary supplements can affect the way warfarin works. These may include:

    Before taking any new drug, including over-the-counter medications, herbal products, vitamins, nutritionalsupplements, or medication prescribed by another doctor or dentist, check with the doctor who monitors your warfarin medication. Your warfarin doctor may need to adjust your warfarin dosage or may recommend another medication less likely to interfere with warfarin.


    • Eat a sensible, well-balanced diet.
    • Talk with your doctor if you are planning any major dietary changes such as following a weight-reducing diet or adding nutritional supplements.
    • Large amounts of food high in vitamin K (such as broccoli, spinach and turnip greens) may change the way warfarin works. Try to keep the amount of these foods in your diet about the same from week to week.
    • It is best to avoid alcohol while taking warfarin. Alcohol interferes with its effectiveness.
    • Some herbal teas may cause the INR to become high or low.


    • Check with your doctor before starting any exercise or sports program. Your doctor may want you to avoid any activity or sport that may result in a serious fall or other injury.
    • Use a soft toothbrush. Brush and floss gently to prevent bleeding from the gums.
    • Be careful when using razors. If you cut yourself, follow the guidelines below.

    Illness and Emergencies

    • If you cut yourself and 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 you cut yourself and the cut is large, apply constant pressure and get help immediately either by phone or by going to the nearest emergency room. Call your doctor if you have any symptoms of illness such as vomiting, diarrhea, infection, or fever. Illness can change the way warfarin works.
    • It is recommended that you wear or carry identification that states you are taking warfarin.
    • Avoid situations where you may get injured at home or at work.

    If you are a woman who is taking warfarin and is 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 since warfarin can have serious effects on your baby.

    Surgery and Dental Work
    Before any surgery or dental work is done, tell all your doctors and dentists that you are taking warfarin. Before having a surgical or dental procedure, you may need to have a blood test, and you may need to stop taking warfarin for a few days. Do not stop taking warfarin without first consulting with the doctor who monitors your warfarin/INR.

    Check with your doctor before you travel. Before you go on vacation, you may need to have a blood test and your warfarin dose may need to be adjusted. While traveling, carry your medications with you at all times. Do not put medications in checked baggage, and do not leave your medications in the car.

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