Fondaparinux (By injection)

Fondaparinux (fon-da-PAR-in-ux)

Treats and prevents blood clots. This medicine is a blood thinner.

Brand Name(s):

Arixtra

When This Medicine Should Not Be Used:

How to Use This Medicine:

Injectable

• Your doctor will prescribe your exact dose and tell you how often it should be given. This medicine is given as a shot under your skin. It is usually given in the stomach.
• A nurse or other health provider will give you this medicine.
• You may be taught how to give your medicine at home. Make sure you understand all instructions before giving yourself an injection. Do not use more medicine or use it more often than your doctor tells you to.
• Check the liquid in the prefilled syringe. It should be clear to colorless. Do not use it if it is discolored or if you see particles in it. Do not use it if it is cracked, broken, bent, or has a leak.
• Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
• Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
• If you store this medicine at home, keep it at room temperature, away from heat and direct light. Throw away prefilled syringe that has been left at room temperature for more than 4 hours.
• Throw away used needles in a hard, closed container that the needles cannot poke through. Keep this container away from children and pets.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Some medicines can affect how fondaparinux works. Tell your doctor if you are using an NSAID pain or arthritis medicine (including aspirin, ibuprofen, naproxen) or other blood thinners (including clopidogrel, warfarin).

Warnings While Using This Medicine:

• Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease, liver disease, bleeding problems, high blood pressure, diabetic retinopathy, stomach ulcer, or a history of stroke or heart infection. Tell your doctor if you recently had brain, back, or eye surgery. Tell your doctor if you have an allergy to latex.
• This medicine may cause the following problems:
  • Increased risk of bleeding
  • Risk of spinal or epidural blood clots after spinal procedures
• This medicine lowers the number of certain blood cells, so you may bleed or bruise more easily. Be careful to avoid injuries.
• Tell any doctor or dentist who treats you that you are using this medicine. You may need to stop using this medicine several days before you have surgery or medical tests.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Blood in your urine or stools
• Change in how much or how often you urinate
• Loss of bowel or bladder control
• Numbness or tingling in your legs, back pain
• Tiny red dots on the skin, especially on the lower legs
• Unexplained nosebleeds
• Unusual bleeding, bruising, or weakness

If you notice these less serious side effects, talk with your doctor:

• Mild bleeding, itching, or rash where the shot was given

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 3/4/2025