Fondaparinux
Fondaparinux is a synthetic anticoagulant that works by selectively inhibiting Factor Xa through its binding to antithrombin III, preventing blood clot formation. It is primarily used for the prevention and treatment of venous thromboembolic events, including deep vein thrombosis and pulmonary embolism, particularly in patients undergoing major orthopedic surgery or those at risk of blood clots.
Fondaparinux is a injectable anticoagulant that prevents blood clots by inhibiting Factor Xa, used primarily for preventing and treating venous thromboembolism.
This medication carries a boxed (black box) warning — the strongest type of FDA warning. Review the full prescribing information before use.
Key facts at a glance
- ATC
- B01AX05
- RxNorm
- 321208
- Generic
- Fondaparinux
- Class
- atc-b01
- Brands
- Arixtra
- Availability
- rx
- Lactation
- unknown
- Routes
- —
- Forms
- prefilled syringe
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Dosage and administration
- Usual dose
- 2.5mg once daily (prophylaxis) or 5mg once daily (VTE treatment)
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- Not typically recommended; limited pediatric data available
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
- Usual dose
- 2.5mg once daily (prophylaxis) with caution due to renal function
- Maximum
- consult physician
- Frequency
- once daily
- Instructions
- Follow physician instructions
- Duration limits
- as prescribed
- Monitoring
- standard
Overdose information
Special Populations
9 groupspregnancy
first trimesteravoid if possible
avoid use during pregnancy unless benefits outweigh risks
regular fetal monitoring and ultrasound assessments
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
second trimesteravoid if possible
avoid use unless benefits outweigh risks, consider alternative anticoagulants
regular fetal monitoring, ultrasound for fetal growth
Use of this medication in this population requires careful consideration of risks and benefits.
pregnancy
third trimesteravoid if possible
discontinue before delivery if possible, avoid close to delivery
fetal monitoring, careful delivery planning, assess bleeding risk
Use of this medication in this population requires careful consideration of risks and benefits.
lactation
breastfeedingdiscontinue breastfeeding or avoid drug
fondaparinux is excreted in breast milk, breastfeeding should be discontinued during treatment
no specific monitoring required if breastfeeding discontinued
Use of this medication in this population requires careful consideration of risks and benefits.
geriatric
elderlyreduce starting dose, use lower therapeutic doses
use with caution due to increased bleeding risk, start at lower end of dosing range
regular renal function monitoring, watch for signs of bleeding, frequent CBC checks
Use with caution and monitor for adverse effects.
pediatric_age
children adolescentsnot established for pediatric use
not recommended for use in children under 18 years due to limited safety and efficacy data
no standard monitoring established, use only in specialized pediatric centers
renal_impairment
severedo not use in severe impairment
contraindicated in patients with severe renal impairment (CrCl less than 30 mL/min)
assess renal function before initiating therapy
Use of this medication in this population requires careful consideration of risks and benefits.
renal_impairment
moderateuse with caution, consider dose reduction
use with caution in moderate renal impairment (CrCl 30-50 mL/min), monitor closely
frequent renal function monitoring, monitor for signs of bleeding
Use with caution and monitor for adverse effects.
hepatic_impairment
severeuse with extreme caution, may require dose reduction
use with caution in severe hepatic impairment due to coagulopathy risk
monitor liver function, coagulation parameters, watch for bleeding
Use with caution and monitor for adverse effects.
Statistics and clinical data
FDA approval year
FDA approval year for Fondaparinux (Arixtra)
Drug class
Pharmacological classification of Fondaparinux
Common uses
Primary therapeutic indications
Mechanism of action
Pharmacodynamic mechanism
Prevention of venous thromboembolic events (VTE) in patients undergoing major orthopedic surgery of the legs or hips; treatment of acute DVT and pulmonary embolism; sometimes used in acute coronary syndromes.
Fondaparinux selectively binds to antithrombin III, potentiating its ability to neutralize Factor Xa by approximately 300-fold, thereby interrupting the coagulation cascade and preventing thrombin generation and clot formation.
Administered as a once-daily subcutaneous injection. Contraindicated in patients with severe renal impairment, active bleeding, or bacterial endocarditis. Requires careful monitoring for bleeding complications and may increase risk of spinal/epidural hematoma in patients undergoing neuraxial anesthesia.
Contraindications
Conditions and patient states where this medication should be avoided or used with caution.
Do not use (1)
Known allergy to this medication or its components
Use caution (1)
Consult healthcare provider for benefits vs risks assessment
Official drug label
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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy