Fondaparinux

The antithrombotic activity of fondaparinux sodium is the result of antithrombin III (ATIII)-mediated selective inhibition of Factor Xa. By selectively binding to ATIII, fondaparinux sodium potentiates (about 300 times) the innate neutralization of Factor Xa by ATIII.

• Fondaparinux sodium injection is a Factor Xa inhibitor (anticoagulant) indicated for: Prophylaxis of deep vein thrombosis (DVT) in patients undergoing hip fracture surgery (including extended prophylaxis), hip replacement surgery, knee replacement surgery, or abdominal surgery. (1.1) Treatment of DVT or acute pulmonary embolism (PE) when administered in conjunction with warfarin.ICD-10: I26.99, I82.409

• Fondaparinux sodium injection is contraindicated in the following conditions: Severe renal impairment (creatinine clearance [CrCl] <30 mL/min). [see Warnings and Precautions ( 5.3 ) and Use in Specific Populations (8.6) ] Active major bleeding.contraindicated

For subcutaneous use, do not mix with other injections or infusions. ( 2.1 ) Prophylaxis of deep vein thrombosis: Fondaparinux sodium 2.5 mg subcutaneously once daily after hemostasis has been established. The initial dose should be given no earlier than 6 to 8 hours after surgery and continued for 5 to 9 days. For patients undergoing hip fracture surgery, extended prophylaxis up to 24 additional days is recommended. ( 2.2 , 2.3 ) Treatment of deep vein thrombosis and pulmonary embolism: Fondaparinux sodium 5 mg (body weight <50 kg), 7.5 mg (50 to 100 kg), or 10 mg (>100 kg) subcutaneously once daily. Treatment should continue for at least 5 days until INR 2 to 3 achieved with warfarin sodium. ( 2.4 ) 2.1 Important Dosing Information Do not mix other medications or solutions with fondaparinux sodium injection. Administer fondaparinux sodium injection only subcutaneously. Discard unused portion. 2.2 Deep Vein Thrombosis Prophylaxis Following Hip Fracture, Hip Replacement, and Knee Replacement Surgery In patients undergoing hip fracture, hip replacement, or knee replacement surgery, the recommended dose of fondaparinux sodium injection is 2.5 mg administered by subcutaneous injection once daily after hemostasis has been established. Administer the initial dose no earlier than 6 to 8 hours after surgery. Administration of fondaparinux sodium injection earlier than 6 hours after surgery increases the risk of major bleeding. The usual duration of therapy is 5 to 9 days; up to 11 days of therapy was administered in clinical trials.

Spinal or epidural hematomas, which may result in long-term or permanent paralysis, can occur ( 5.1 ) Patients taking fondaparinux sodium injection with risk factors for bleeding are at increased risk of hemorrhage. ( 5.2 ) Bleeding risk is increased in renal impairment and in patients with low body weight <50 kg ( 5.3 , 5.4 ) Thrombocytopenia can occur with administration of fondaparinux sodium. ( 5.5 ) Periodic routine complete blood counts (including platelet counts), serum creatinine level, and stool occult blood tests are recommended. ( 5.6 ) 5.1 Neuraxial Anesthesia and Post-operative Indwelling Epidural Catheter Use Spinal or epidural hematomas, which may result in long-term or permanent paralysis, can occur with the use of anticoagulants and neuraxial (spinal/epidural) anesthesia or spinal puncture. The risk of these events may be higher with post-operative use of indwelling epidural catheters or concomitant use of other drugs affecting hemostasis such as NSAIDs [see Boxed Warning ]. In the postmarketing experience, epidural or spinal hematoma has been reported in association with the use of fondaparinux sodium by subcutaneous (SC) injection. Optimal timing between the administration of fondaparinux sodium and neuraxial procedures is not known. Monitor patients undergoing these procedures for signs and symptoms of neurologic impairment such as midline back pain, sensory and motor deficits (numbness, tingling, or weakness in lower limbs), and bowel or bladder dysfunction.

The following clinically significant adverse reactions are described elsewhere in the labeling: • Spinal or epidural hematomas [see Warnings and Precautions ( 5.1 ) ] • Hemorrhage [see Warnings and Precautions ( 5.2 )] • Renal impairment and bleeding risk [see Warnings and Precautions ( 5.3 ) ] • Body weight <50 kg and bleeding risk [see Warnings and Precautions ( 5.4 ) ] • Thrombocytopenia [see Warnings and Precautions ( 5.5 ) ] The most serious adverse reactions associated with the use of fondaparinux sodium are bleeding complications. ( 6.1) To report SUSPECTED ADVERSE REACTIONS, contact Dr. Reddy’s Laboratories, Inc. at 1-888-375-3784 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The adverse reaction information below is based on data from 8,877 patients exposed to fondaparinux sodium in controlled trials of hip fracture, hip replacement, major knee, or abdominal surgeries, and DVT and PE treatment. Hemorrhage During administration of fondaparinux sodium, the most common adverse reactions were bleeding complications [see Warnings and Precautions ( 5.2 ) ].

Safety and effectiveness of fondaparinux sodium in pediatric patients have not been established. Because the risk for bleeding during treatment with fondaparinux sodium is increased in adults who weigh <50 kg, bleeding may be a particular safety concern for use of fondaparinux sodium in the pediatric population. ( 4 , 5.4 ) Because elderly patients are more likely to have reduced renal function, fondaparinux sodiumshould be used with caution in these patients. (8.5) The risk of bleeding is increased with reduced renal or hepatic function. ( 8.6 , 8.7 ) 8.1 Pregnancy Risk Summary Available data from published literature and postmarketing reports have not reported a clear association with fondaparinux sodium and adverse developmental outcomes. Fondaparinux sodium plasma concentrations obtained from four women treated with fondaparinux sodium injection during pregnancy and their newborn infants demonstrated low placental transfer of fondaparinux sodium (see Data). There are risks to the mother associated with untreated venous thromboembolism in pregnancy and a risk of hemorrhage in the mother and fetus associated with use of anticoagulants (see Clinical Considerations).

Metabolism

Absorption: Fondaparinux sodium administered by subcutaneous injection is rapidly and completely absorbed (absolute bioavailability is 100%). Following a single subcutaneous dose of fondaparinux sodium 2.5 mg in young male subjects, C max of 0.34 mg/L is reached in approximately 2 hours.

There is no known antidote for fondaparinux sodium. Overdose of fondaparinux sodium may lead to hemorrhagic complications. Discontinue treatment and initiate appropriate therapy if bleeding complications associated with overdosage occur. Data obtained in patients undergoing chronic intermittent hemodialysis suggest that clearance of fondaparinux sodium can increase by 20% during hemodialysis.

• Dec 7, 2001NDANDA021345Mylan Ireland Ltd
• Jul 11, 2011ANDAANDA091316Dr Reddys Labs Ltd
• Dec 26, 2017ANDAANDA206918Eugia Pharma
• May 15, 2018ANDAANDA206812Hengrui Pharma
• Nov 14, 2018ANDAANDA208615Scinopharm Taiwan

1. 1Anaemia6107.6%
2. 2Haematoma5597.0%
3. 3Pulmonary Embolism4445.5%
4. 4Off Label Use3664.6%
5. 5Haemorrhage3514.4%
6. 6Haemoglobin Decreased3394.2%
7. 7Death2963.7%
8. 8Deep Vein Thrombosis2933.7%
9. 9Dyspnoea2703.4%
10. 10Thrombocytopenia2623.3%
11. 11Drug Ineffective2583.2%
12. 12Pyrexia2413.0%
13. 13Nausea2342.9%
14. 14Thrombosis2332.9%
15. 15Vomiting2312.9%

Recent PubMed references pinned to Fondaparinux as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

• Fondaparinux-Enabled Competitive Lateral Flow Assay for Monitoring Lactoferrin Bioactivity during Dairy Processing.
  Langmuir : the ACS journal of surfaces and colloids · 2026 · Zhai Y, Zheng X, Liu L, et al.
  PMID 42095507DOI 10.1021/acs.langmuir.6c00787
• Disproportionality analysis of fondaparinux associated adverse events based on the FDA adverse event reporting system.
  PloS one · 2026 · Kang F, Wang Y, Cai F, et al.
  PMID 41671250DOI 10.1371/journal.pone.0342548
• Design and rationale of aspirin versus aspirin and fondaparinux prior to early invasive strategy in patients with NSTEMI: The FOXY trial.
  American heart journal · 2026 · Fur CB, Olsen NT, Lassen JF, et al.
  PMID 40945808DOI 10.1016/j.ahj.2025.09.006
• Safety and efficacy of fondaparinux use in hemodialysis patients with heparin-induced thrombocytopenia: a systematic review.
  European journal of clinical pharmacology · 2025 · Stojadinovic M, Jankovic S, Zivkovic-Zaric R, et al.
  PMID 40925931DOI 10.1007/s00228-025-03913-8
• Evaluation of Antiviral Activity of Lactoferrin in Bovine Milk Toward Fondaparinux Using Ordered Porous Layer Interferometry.
  Analytical chemistry · 2025 · Zhang Y, Liu L, Wan Y, et al.
  PMID 40608812DOI 10.1021/acs.analchem.5c01351
• Efficacy and safety of fondaparinux in elective total hip arthroplasty and hip fracture surgery: a systematic review and meta-analysis.
  Journal of orthopaedic surgery and research · 2025 · Mariscal G, Tarazona-Santabalbina FJ, Marin-Peña O, et al.
  PMID 40442800DOI 10.1186/s13018-025-05950-6
• Evaluating the impact of continuous venovenous hemodiafiltration on the efficacy of prophylactic fondaparinux doses: a prospective single-center observational study.
  Scientific reports · 2025 · Aszkiełowicz A, Steckiewicz KP, Owczuk R, et al.
  PMID 40413237DOI 10.1038/s41598-025-03365-1
• A Single-Domain VNAR Nanobody Binds with High-Affinity and Selectivity to the Heparin Pentasaccharide Fondaparinux.
  International journal of molecular sciences · 2025 · Gschwandtner M, Derler R, Talker E, et al.
  PMID 40362285DOI 10.3390/ijms26094045

The 10 most recently updated of 96 ClinicalTrials.gov registrations naming Fondaparinux as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Treatment With Aspirin Alone Versus Aspirin in Combination With Fondaparinux Before Early Coronary Assessment in Patients With Non-ST-Elevation Myocardial Infarction
  Recruiting · Phase 4 · Interventional · 5,076 enrolled · University of Aarhus
  NCT06710184updated 2026-05-04
• Intravenous Immunoglobulin for the Treatment of Acute Exacerbations of Idiopathic Pulmonary Fibrosis
  Recruiting · Phase 3 · Interventional · 196 enrolled · Argyrios Tzouvelekis
  NCT07299695updated 2026-03-16
• Thromboprophylaxis in Lower Limb Immobilisation
  Recruiting · Phase 3 · Interventional · 10,044 enrolled · Queen Mary University of London
  NCT06370273updated 2026-01-06
• Hip Fracture Surgery Arterial and Venous Thrombotic Events Prevention
  Not yet recruiting · Phase 3 · Interventional · 100 enrolled · McMaster University
  NCT07228663updated 2025-11-14
• Hokusai Study in Pediatric Patients With Confirmed Venous Thromboembolism (VTE)
  Completed · Phase 3 · Interventional · 290 enrolled · Daiichi Sankyo
  NCT02798471updated 2025-02-28
• Coagulopathy of COVID-19: A Pragmatic Randomized Controlled Trial of Therapeutic Anticoagulation Versus Standard Care
  Completed · Phase 3 · Interventional · 465 enrolled · Unity Health Toronto
  NCT04362085updated 2025-01-30
• Management of Atrial Fibrillation in Patients With Cancer (MAFIC Study)
  Withdrawn · Observational · 0 enrolled · AHEPA University Hospital
  NCT04508855updated 2024-07-30
• Multicentric Prospective Validation of a Universal Test to Quantify Apixaban, Rivaroxaban, Danaparoid and Fondaparinux Levels
  Unknown · Observational · 2,100 enrolled · Nantes University Hospital
  NCT04539301updated 2024-05-07
• Endovenous Laser Ablation in Acute Thrombophlebitis of the Varicose Great Saphenous Vein
  Completed · Phase 4 · Interventional · 105 enrolled · National Medical Research Center for Therapy and Preventive Medicine
  NCT05001776updated 2023-12-20
• Direct Oral Anticoagulants (DOACs) Versus LMWH +/- Warfarin for VTE in Cancer
  Completed · Interventional · 811 enrolled · Alliance Foundation Trials, LLC.
  NCT02744092updated 2023-10-03

Frequently asked questions

How does Fondaparinux work?

The antithrombotic activity of fondaparinux sodium is the result of antithrombin III (ATIII)-mediated selective inhibition of Factor Xa. By selectively binding to ATIII, fondaparinux sodium potentiates (about 300 times) the innate neutralization of Factor Xa by ATIII.

What is Fondaparinux used for?

According to FDA labeling, Fondaparinux carries indications including: Fondaparinux sodium injection is a Factor Xa inhibitor (anticoagulant) indicated for: Prophylaxis of deep vein thrombosis (DVT) in patients undergoing hip fracture surgery (including extended prophylaxis), hip replacement surgery, knee replacement surgery, or abdominal surgery. (1.1) Treatment of DVT or acute pulmonary embolism (PE) when administered in conjunction with warfarin.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.

What class of drug is Fondaparinux?

Fondaparinux is classified as Other antithrombotic agents, Factor Xa Inhibitor, Antithrombins, Factor Xa Inhibitors, Decreased Coagulation Factor Activity.

What are the brand names for Fondaparinux?

Fondaparinux is marketed under brand names including Arixtra.

What are the contraindications for Fondaparinux?

Fondaparinux labeling lists contraindications including: Fondaparinux sodium injection is contraindicated in the following conditions: Severe renal impairment (creatinine clearance [CrCl] <30 mL/min). [see Warnings and Precautions ( 5.3 ) and Use in Specific Populations (8.6) ] Active major bleeding.. Always consult the full prescribing information and a clinician.