Fondaparinux: Uses, Side Effects

Fondaparinux blocks the activity of certain clotting substances in the blood.

Fondaparinux is used to prevent a type of blood clot called deep vein thrombosis (DVT), which can lead to blood clots in the lungs (pulmonary embolism). A DVT can occur after certain types of surgery.

Fondaparinux is also used together with warfarin (Coumadin, Jantoven) to treat DVT, including pulmonary embolism.

Fondaparinux may also be used for purposes not listed in this medication guide.

Before taking this medicine

You should not use this medicine if you have ever had a severe allergic reaction to fondaparinux, or if you have:

  • active or uncontrolled bleeding;
  • severe kidney disease;
  • an infection in the lining of your heart (also called bacterial endocarditis); or
  • a low level of platelets in your blood after testing positive for a certain antibody while using fondaparinux.

You should not use fondaparinux to prevent blood clots after surgery if you weigh less than 110 pounds (50 kilograms).

Tell your doctor if you have ever had:

  • a bleeding disorder that is inherited or caused by disease;
  • a stroke;
  • eye problems caused by diabetes;
  • uncontrolled high blood pressure;
  • stomach or intestinal bleeding or ulcer;
  • brain, spine, or eye surgery;
  • an allergy to latex; or
  • liver or kidney disease.

Using fondaparinux during pregnancy may cause bleeding in the mother or the unborn baby. Tell your doctor if you are pregnant or if you become pregnant.

It may not be safe to breast-feed while using this medicine. Ask your doctor about any risk.

Side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Also seek emergency medical attention if you have symptoms of a spinal blood clot: back pain, numbness or muscle weakness in your lower body, or loss of bladder or bowel control.

Fondaparinux can cause you to bleed more easily. Call your doctor at once if you have signs of bleeding such as:

  • easy bruising or bleeding (nosebleeds, bleeding gums, heavy menstrual bleeding);
  • pain, swelling, or drainage from a wound or where a needle was injected in your skin;
  • bleeding from wounds or needle injections, any bleeding that will not stop;
  • headaches, dizziness, weakness, feeling like you might pass out;
  • urine that looks red, pink, or brown; or
  • bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds.

Also call your doctor at once if you have:

  • a light-headed feeling, like you might pass out;
  • low potassium level–leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling;
  • low red blood cells (anemia)–pale skin, unusual tiredness, feeling light-headed or short of breath, cold hands and feet;
  • low potassium–leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling;
  • low red blood cells (anemia)–pale skin, feeling light-headed or short of breath, rapid heart rate, trouble concentrating; or

Common side effects may include:

  • bleeding, bruising;
  • sleep problems (insomnia);
  • rash, blisters;
  • dizziness, confusion; or
  • minor bleeding, rash, itching, or oozing where the medicine was injected.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

What other drugs will affect fondaparinux?

Tell your doctor about all your other medicines, especially:

  • any other medications to treat or prevent blood clots;
  • a blood thinner–heparin warfarin (Coumadin, Jantoven); or
  • NSAIDs (nonsteroidal anti-inflammatory drugs) –aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib, diclofenac, indomethacin, meloxicam, and others.

This list is not complete, and many other drugs may affect fondaparinux. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.


Keyword: fondaparinux.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.