Low Molecular Weight Heparin (LMWH) Patient Education Handout associated with UMHS Clinical Care Guideline

This information is not a tool for self-diagnosis or a substitute for medical treatment. You should speak to your health-care provider or make an appointment to be seen if you have questions or concerns about this information or your medical condition.

Spanish version

What is Low Molecular Weight Heparin?

Low molecular weight heparin (LMWH) is a medication which thins the blood. It helps prevent blood clots from forming in the veins and treats blood clots already present in the veins by preventing the blood clot from extending or getting larger. LMWH is generally used for only a short period of time for anticoagulation (blood thinning), while coumadin (a blood thinner in pill form) is for longer term anticoagulation.

It can be given once or twice a day by a simple injection under the skin. The patient or family member can be taught to give the injection. The use of LMWH has allowed patients with blood clots to be treated at home, or with only a short hospital stay in some cases.

What are the side effects?

The major side effect associated with LMWH, as with any blood thinner, is bleeding. You must notify your physician if you have any unusual bleeding, for example, heavy nosebleeds, bleeding gums, vomiting blood, blood in bowel movements, or heavy vaginal bleeding.

LMWH can cause local irritation or inflammation (tenderness and redness) at the injection site. Call your physician if you develop any generalized rash or reaction.

What else do I need to know?

You should avoid the use of any other medications which may increase your risk of bleeding while you are on LMWH. This includes aspirin, nonsteroidal anti-inflammatory medications (ibuprofen, naproxen, etc.), COX II Inhibitors (Celebrex, and Bextra), as well as some herbal medications/supplements which can cause blood thinning. Always consult your physician before you begin any new medication, including any over the counter medications. Notify all of your medical providers (dentist, podiatrist, gynecologist, etc.) that you are on a blood thinning medication.