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    Anticoagulants for Heart Valve Disease



    Generic Name Brand Name
    warfarin Coumadin

    Low-molecular-weight heparins (LMWH)

    Generic Name Brand Name
    dalteparin Fragmin
    enoxaparin Lovenox
    tinzaparin Innohep

    Unfractionated heparins (UH)

    Generic Name

    How It Works

    Anticoagulant medicines (also known as blood thinners) help prevent the formation of blood clots by increasing the time it takes a blood clot to form. This prevents a clot that has already formed from getting larger and reduces the chances that pieces of a clot will break off and cause a heart attack or stroke.

    Why It Is Used

    Anticoagulants are used after heart valve replacement surgery. After surgery, you have a higher risk for dangerous blood clots.

    • If you have a mechanical valve (made with metal or plastic), you will take the anticoagulant warfarin (Coumadin) for the rest of your life.
    • If you have a biological valve (made with tissue), you may take warfarin for a few months after surgery. Then, when you no longer take warfarin, you may take a low-dose aspirin every day.

    After heart valve replacement surgery, both warfarin and one of several types of anticoagulant medicines-a low-molecular-weight heparin, an unfractionated heparin, or another antithrombotic medicine-are started. Coumadin is given in pill form while the other medicines are given as a shot. The injected medicines act immediately, while Coumadin takes several days to become effective. When warfarin begins to work, the other medicines are stopped.

    How Well It Works

    Anticoagulants lower the risk of dangerous blood clots after valve replacement surgery.

    Side Effects

    All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

    Here are some important things to think about:

    • Usually the benefits of the medicine are more important than any minor side effects.
    • Side effects may go away after you take the medicine for a while.
    • If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

    Allergic reaction

    Call911or other emergency services right away if you have:

    Call your doctor if you have:


    Call 911 or other emergency services right away if you have:

    Call your doctor now or seek immediate medical care if you have:

    • Any abnormal bleeding, such as:

    If you are injured, apply pressure to stop the bleeding. Realize that it will take longer than you are used to for the bleeding to stop. If you can't get the bleeding to stop, call your doctor.

    Heparin: Side effects often happen at injection sites. These side effects include:

    • Pain.
    • Irritation.
    • Bruising.

    Warfarin: Other side effects include:

    See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

    What To Think About

    When you take anticoagulants, you need to take extra steps to avoid bleeding problems.

    Warfarin. If you take warfarin, you need to:

    • Get regular blood tests.
    • Prevent falls and injuries.
    • Eat a steady diet, and pay attention to foods that contain vitamin K.
    • Tell your doctors about all other medicines and vitamins that you take.

    For more information, see:

    actionset.gif Warfarin: Taking Your Medicine Safely.

    Heparin. If you take heparin, you need to:

    • Learn how to give yourself the shot.
    • Prevent falls and injuries.
    • Prevent medicine interactions.

    For more information, see:

    actionset.gif Blood Thinners Other Than Warfarin: Taking Them Safely.

    Long-term use of heparin is not typically recommended. It requires one or two injections each day. And long-term use is linked with osteoporosis.

    Taking medicine

    Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

    There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

    Advice for women


    Do not take warfarin if you are pregnant. Warfarin can cause miscarriage or birth defects. If you are taking warfarin, talk to your doctor about how you can prevent pregnancy.

    If you think you might be pregnant: Call your doctor. If you are pregnant, you will take heparin during your pregnancy.

    If you plan on getting pregnant: Talk with your doctor. You and your doctor will decide which medicine you will take-warfarin or heparin-while trying to get pregnant.


    If you are pregnant: You will take heparin during your pregnancy. Heparin has not been shown to affect the fetus.

    For more information, see Pregnancy and the Increased Risk of Developing Blood Clots.


    Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

    Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

    ByHealthwise Staff
    Primary Medical ReviewerRakesh K. Pai, MD, FACC - Cardiology, Electrophysiology
    Specialist Medical ReviewerStephen Fort, MD, MRCP, FRCPC - Interventional Cardiology

    Current as ofAugust 8, 2014

    WebMD Medical Reference from Healthwise

    Last Updated: August 08, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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