fondaparinux sodium at a glance
Medicine class
Synthetic anticoagulant and selective indirect factor Xa inhibitor
Main roles
Preventing venous thromboembolism in selected surgical or immobilised adults, and treating eligible superficial-vein thrombosis
How it is given
A pre-filled syringe injected under the skin of the lower abdomen; it must not be injected into muscle
Important practical point
Leave the syringe’s air bubble in place and alternate injection sites
What is fondaparinux sodium used for?
The selected product is licensed in adults for:
Preventing venous thromboembolism after major lower-limb orthopaedic surgery, including hip fracture, knee or hip replacement surgery
Preventing venous thromboembolism after abdominal surgery in people judged to have a high clot risk, including some cancer surgery
Preventing venous thromboembolism in high-risk medical patients immobilised by an acute illness
Treating acute, symptomatic, spontaneous superficial-vein thrombosis of the lower limb when deep-vein thrombosis has been excluded and the product’s eligibility criteria are met
How does fondaparinux sodium work?
Fondaparinux binds to antithrombin and greatly strengthens its inhibition of activated factor X. This interrupts the clotting cascade, reduces thrombin formation and makes clot development less likely. It does not directly inhibit thrombin or normally act on platelets.
fondaparinux sodium preparations and strengths
Injection
Route: Parenteral
Strengths: 1.5 mg/0.3 mL, 2.5 mg/0.5 mL, 5 mg/0.4 mL, 7.5 mg/0.6 mL, 10 mg/0.8 mL
How to take fondaparinux sodium
Use fondaparinux exactly as demonstrated by a healthcare professional. It is supplied as a single-use pre-filled syringe for deep injection under the skin, not into muscle.
Inject into a pinched skin fold on either side of the lower abdomen, alternating sides
Insert the needle straight into the skin fold and hold the fold throughout the injection
Do not expel the air bubble before injecting
Do not rub the area afterwards, as this can increase bruising
Do not use a damaged syringe or solution containing particles or discolouration
Place used syringes directly into the supplied sharps container
fondaparinux sodium side effects
Common or expected effects
- Bleeding, such as nose, gum, wound, urinary or gastrointestinal bleeding
- Bruising or a local collection of blood
- Anaemia
Get urgent medical advice
- Severe, persistent or internal bleeding
- Bleeding in the brain or behind the abdominal cavity
- Severe allergic reaction with facial or mouth swelling, breathing difficulty or collapse
- A major fall in platelets or another clinically important clotting abnormality
fondaparinux sodium in pregnancy
Fondaparinux should be used during pregnancy only when clearly necessary. Evidence remains limited and generally low quality, so decisions should involve obstetric and anticoagulation specialists who can balance clotting and bleeding risks.
fondaparinux sodium while breastfeeding
It is unknown whether fondaparinux passes into human milk. The selected product information does not recommend breastfeeding during treatment, although absorption by the infant’s gut is considered unlikely. Discuss alternatives and feeding plans with the specialist team.
fondaparinux sodium interactions
The main interaction concern is increased bleeding risk. Tell the prescriber about prescribed, over-the-counter and herbal products.
Other anticoagulants, including heparins and warfarin
Combining anticoagulants can substantially increase bleeding risk and should occur only under a planned specialist transition or clear clinical direction.
Antiplatelet medicines, including aspirin and clopidogrel
These can add to bleeding risk, requiring a clear indication and close observation.
Non-steroidal anti-inflammatory drugs, including ibuprofen and piroxicam
These can increase bleeding, particularly from the stomach or bowel. Check with a clinician or pharmacist before use.
Common questions about fondaparinux sodium
Answers are fully visible for fast scanning and source review.
What type of anticoagulant is fondaparinux sodium?
It is a synthetic anticoagulant that indirectly and selectively inhibits factor Xa through antithrombin.
Is fondaparinux sodium the same as heparin?
No. It is a synthetic pentasaccharide with a more selective mechanism, although both reduce clot formation and can cause bleeding.
Can it be injected into muscle?
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.