Skip to Content
Looking to save on your medications?  Find out how 


Generic name: fondaparinux sodium

What is Arixtra?

Arixtra is a prescription medicine that is used to:

  • help prevent blood clots from forming in people who have had certain surgeries of the hip, knee, or the stomach area (abdominal surgery)
  • treat people who have blood clots in their legs or blood clots that travel to their lungs, along with the blood thinner medicine warfarin.

It is not known if Arixtra is safe and effective for use in children younger than 18 years of age.

What is the most important information I should know about Arixtra?

Arixtra may cause serious side effects, including:

  • Spinal or epidural blood clots (hematoma). People who take a blood thinner medicine (anticoagulant) like Arixtra, and have medicine injected into their spinal and epidural area, or have a spinal puncture have a risk of forming a blood clot that can cause long-term or permanent loss of the ability to move (paralysis). Your risk of developing a spinal or epidural blood clot is higher if:
    • a thin tube called an epidural catheter is placed in your back to give you certain medicine
    • you take NSAIDs or a medicine to prevent blood from clotting
    • you have a history of difficult or repeated epidural or spinal punctures
    • you have a history of problems with your spine or have had surgery on your spine
  • If you take Arixtra and receive spinal anesthesia or have a spinal puncture, your doctor should watch you closely for symptoms of spinal or epidural blood clots. Tell your doctor right away if you have back pain, tingling, numbness, muscle weakness (especially in your legs and feet), loss of control of the bowels or bladder (incontinence).
  • Because the risk of bleeding may be higher, tell your doctor before taking Arixtra if you:
    • are also taking certain other medicines that affect blood clotting such as aspirin, an NSAID (for example, ibuprofen or naproxen), clopidogrel, or warfarin sodium
    • have bleeding problems
    • had problems in the past with pain medication given through the spine
    • have had surgery to your spine
    • have a spinal deformity

Who should not take Arixtra?

Do not take Arixtra if you:

  • have certain kidney problems
  • have active bleeding problems
  • have an infection in your heart
  • have low platelet counts and if you test positive for a certain antibody while you are taking Arixtra
  • weigh less than 110 pounds (50 kg) to prevent blood clots from surgery. See, “What are the possible side effects of Arixtra?
  • had a serious allergic reaction to Arixtra

What should I tell my healthcare provider before taking Arixtra?

Before taking Arixtra, tell your doctor about all of your medical conditions, including if you:

  • have had any bleeding problems (such as stomach ulcers)
  • have had a stroke
  • have had recent surgeries, including eye surgery
  • have diabetic eye disease
  • have kidney or liver problems
  • have uncontrolled high blood pressure
  • have a latex allergy. The packaging (needle guard) for Arixtra contains dry natural latex rubber.
  • are pregnant or plan to become pregnant. Arixtra may harm your unborn baby. If you are pregnant, talk to your doctor about the best way for you to prevent or treat blood clots.
  • are breastfeeding or plan to breastfeed. It is not known if Arixtra passes into breast milk. You and your doctor should decide if you will breastfeed during treatment with Arixtra.

Tell your doctor about all the medicines you take including prescriptions and over-the-counter medicines, vitamins, and herbal supplements. Some medicines can increase your risk of bleeding.

See “What is the most important information I should know about Arixtra?” Do not start taking any new medicines without first talking to your doctor.

Tell all your doctors and dentist that you take Arixtra, especially if you need to have any kind of surgery or a dental procedure. Keep a list of your medicines and show it to all your doctors and pharmacist before you start a new medicine.

How should I take Arixtra?

  • See the detailed Instructions for Use that comes with Arixtra for information about how to give an Arixtra injection.
  • If your doctor tells you that you may give yourself injections of Arixtra at home, you will be shown how to give the injections first before you do them on your own.
  • Take Arixtra exactly as your doctor tells you to.
  • Arixtra is given by injection under the skin (subcutaneous injection).
  • If you miss a dose of Arixtra, take your dose as soon as you remember. Do not take 2 doses at the same time.
  • If you take too much Arixtra, call your doctor right away.

What are the possible side effects of Arixtra?

Arixtra can cause serious side effects. See “What is the most important information I should know about Arixtra?

  • Severe bleeding. Certain conditions can increase your risk for severe bleeding, including:
    • some bleeding problems
    • some gastrointestinal problems including ulcers
    • some types of strokes
    • uncontrolled high blood pressure
    • diabetic eye disease
    • soon after brain, spine, or eye surgery
  • Certain kidney problems can also increase your risk of bleeding with Arixtra. Your doctor may check your kidney function during your treatment with Arixtra.
  • Increased bleeding risk in people undergoing certain surgeries who weigh less than 110 pounds (50 kg).
  • Low blood platelets (thrombocytopenia). Low blood platelets can happen when you take Arixtra. Platelets are blood cells that help your blood to clot normally. Your doctor may check your platelet counts during your treatment with Arixtra.
    You may bruise or bleed more easily during your treatment with Arixtra, and it may take longer than usual for bleeding to stop. Tell your doctor if you have any signs or symptoms of bleeding, bruising or rash of dark red spots under the skin during your treatment with Arixtra.

Tell your doctor if you have any bleeding, bruising, or a rash of dark spots under the skin (thrombocytopenia).

The most common side effects of Arixtra include:

  • bleeding problems
  • bleeding, rash, and itching at the injection site (injection site reactions)
  • sleep problems (insomnia)
  • low red blood cell count (anemia)
  • increased wound drainage
  • low potassium in your blood (hypokalemia)
  • dizziness
  • purplish spots on skin (purpura)
  • low blood pressure (hypotension)
  • confusion
  • fluid-filled blisters (bullous eruption)
  • blood clots (hematoma)
  • severe bleeding after surgery (post-operative hemorrhage)

These are not all the possible side effects of Arixtra. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

General information about the safe and effective use of Arixtra

Medicines are sometimes prescribed for purposes other than those listed in Patient Information leaflets. Do not use Arixtra for a condition for which it was not prescribed. Do not give Arixtra to other people, even if they have the same symptoms that you have. It may harm them.

You can ask your doctor or pharmacist for information about Arixtra that is written for healthcare professionals.

How should I store Arixtra?

  • Store Arixtra at 68° to 77°F (20° to 25°C).
  • Safely throw away Arixtra that is out of date or no longer needed.

Keep Arixtra and all medicines out of the reach of children.

What are the ingredients in Arixtra?

Active ingredient: fondaparinux sodium

Inactive ingredients: sodium chloride and water for injection

Source: National Library of Medicine. Last updated June 8, 2020.