How It Works
Normally, when an injury that causes bleeding occurs, the body sends out signals that cause blood to clot at the wound, and the clot naturally breaks down as the wound heals. A person prone to abnormal clotting has an imbalance between clot formation and clot breakdown.
Anticoagulant medications prevent new clots from forming and prevent existing clots from growing (extending) by stopping the production of certain proteins that are necessary for blood to clot. They do not break up or dissolve existing blood clots.
Why It Is Used
Heparin can be used to prevent and initially treat a deep vein thrombosis.
When used for prevention, heparin will be given by injection just under the skin a few hours before surgery and 2 to 3 times per day for several days after surgery.
When used for treatment, heparin is given through the vein (intravenously, or IV) in a continuous infusion or by injection just under the skin twice each day. In addition, blood tests will be done at least once per day to monitor the effect of the medication.
How Well It Works
Heparin can be used to treat or prevent a deep vein thrombosis. When used for treatment, heparin prevents new blood clots from forming and prevents existing clots from getting larger. This allows the normal body systems to dissolve the clots that are already formed.
Heparin reduces the chance that a blood clot will get larger. This reduces the risk of getting a blood clot in the lung (pulmonary embolism).
Side Effects
Bleeding is the most common side effect of heparin. This may include:
- Bleeding from an undiagnosed ulcer or growth in the digestive system.
- Serious bleeding in other areas because of an injury or fall.
- Serious bleeding that can occur in the brain, resulting in death (rare).
If you are taking an anticoagulant and develop signs of bleeding, notify your doctor immediately.
Other possible side effects include:
- Rarely, a blood disorder called thrombocytopenia.
- Localized irritation, pain, or bruising at the location where it is given.
- Bone loss, which may occur as a side effect of heparin use that lasts 1 month or more. Heparin is rarely given for longer than 3 to 7 days. However, longer treatment is sometimes required when a person cannot take warfarin (such as during pregnancy).1
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)
What To Think About
Call your doctor immediately if you are bleeding and it does not stop when you apply pressure.
Unfractionated heparin (UH) is given through an IV (intravenous). It requires hospitalization for 3 to 7 days, and frequent blood tests will be needed to monitor the effects of the medication.
Pregnant women can take unfractionated and low-molecular-weight heparin but not warfarin, an oral anticoagulant.
While you are on any blood-thinning medications, changes to your lifestyle may be needed. These changes include:
People with active stomach ulcers or severe liver or kidney disease probably should not take anticoagulants.
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Credits
| Author | Robin Parks, MS |
| Editor | Kathleen M. Ariss, MS |
| Associate Editor | Pat Truman |
| Primary Medical Reviewer | E. Gregory Thompson, MD - Internal Medicine |
| Specialist Medical Reviewer | Jeffrey J. Gilbertson, MD - Cardiovascular Surgery |
| Last Updated | January 26, 2006 |
Jeffrey J. Gilbertson, MD - Cardiovascular Surgery
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