Pulmonary Embolism

Medicines can help prevent repeated episodes of pulmonary embolism by preventing new blood clots from forming or preventing existing clots from getting larger.

Medication choices

Reference Anticoagulants are prescribed when pulmonary embolism is diagnosed or strongly suspected. Normally, when an injury that causes bleeding occurs, the body sends out signals that cause the blood to clot at the wound. The clot naturally breaks down as the wound heals. A person who is prone to abnormal clotting has an imbalance between clot formation and clot breakdown. Anticoagulants prevent the production of certain proteins that are needed for blood to clot. Although anticoagulants can prevent new clots from forming and prevent existing clots from getting larger, they do not break up or dissolve existing blood clots.

Heparin and warfarin are the two main types of anticoagulants used to treat pulmonary embolism.

Heparin

Heparin is an anticoagulant given by injection. It immediately affects the clotting system in your body. Oral anticoagulant medicine (warfarin) takes longer to start working.

• Low-molecular-weight heparin (LMWH) as initial treatment is usually preferred because it can be given as an injection once or twice a day, and it may be given at home, which allows you to leave the hospital earlier. Blood tests aren't usually needed to monitor LMWH's clotting effect.
• Unfractionated heparin is another form that can be used. It is given in the hospital. Unfractionated heparin is usually given continuously through your vein (intravenously, or IV), but it can also be given as an injection under the skin. Frequent blood tests are used to monitor the clotting effects of this medicine.

Warfarin (such as Coumadin)

Warfarin is an anticoagulant that is taken in pill form. It is usually started while a person is still being treated with heparin because it takes several days for warfarin to build up to a level that's effective. When the warfarin is at a proper level, heparin is stopped and treatment with warfarin continues.

Typically, warfarin is given for at least 3 months after pulmonary embolism to reduce the risk of having another blood clot. Treatment with anticoagulants may continue throughout your life if the risk of having another pulmonary embolism remains high.

Because warfarin can increase the risk of birth defects, Reference pregnant women with a risk of developing blood clots are limited to taking heparin.

Thrombolytics

Reference Clot-dissolving (thrombolytic) medicines are not commonly used to treat pulmonary embolism. Although they can quickly dissolve a blood clot, thrombolytics also greatly increase the risk of serious bleeding. They are occasionally used to treat a life-threatening pulmonary embolism.

What to think about

After pulmonary embolism is diagnosed, a doctor considers:

• Whether anticoagulant medicines are appropriate.
• How long anticoagulants should be used.

If you have recently had a major stroke, surgery, or active internal bleeding, you usually cannot take anticoagulant or thrombolytic medicines. A Reference vena cava filter Opens New Window may help to reduce the risk of another pulmonary embolism in this case.

Safety with anticoagulant medicine

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

Heparin

If you take heparin:

• Reference Prevent injuries.
• Reference Prevent medicine interactions. Do not take any medicines, vitamins, or minerals unless you first talk to your doctor.

Warfarin

If you take warfarin:

• 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:

Reference Reference Warfarin: Taking Your Medicine Safely.

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