Fondaparinux
ARIXTRA
What it isSynthetic pentasaccharide activating antithrombin against factor Xa; VTE prophylaxis and treatment.
Why this oneNegligible HIT cross-reactivity makes it a practical anticoagulant when heparin-induced thrombocytopenia is suspected.
What limits itNo reliable reversal agent exists; renal accumulation increases bleeding, and neuraxial procedures risk spinal hematoma.
FDA-approved for
- VTE prophylaxis/treatment (2001)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| DVT prophylaxis (hip fracture, hip/knee replacement, abdominal surgery) | Adult | 2.5 mg SC QD | 2.5 mg SC QD | 2.5 mg SC QD |
| DVT/PE treatment, body weight <50 kg | Adult | 5 mg SC QD | 5 mg SC QD | 5 mg SC QD |
| DVT/PE treatment, body weight 50-100 kg | Adult | 7.5 mg SC QD | 7.5 mg SC QD | 7.5 mg SC QD |
| DVT/PE treatment, body weight >100 kg | Adult | 10 mg SC QD | 10 mg SC QD | 10 mg SC QD |
Renal Contraindicated if CrCl <30 mL/min; use with caution CrCl 30-50 mL/min
Hepatic No adjustment needed (mild to moderate impairment)
Instructions
- Subcutaneous use only; do not mix with other injections or infusions
- Prophylaxis initial dose no earlier than 6-8 hours after surgery
- Prophylaxis duration 5-9 days (up to 24 additional days for hip fracture)
- Treatment continue ≥5 days until INR 2-3 achieved with warfarin
Contraindications
- Severe renal impairment (CrCl <30 mL/min)
- Active major bleeding
- Bacterial endocarditis
- Thrombocytopenia with a positive anti-platelet antibody test in the presence of fondaparinux
- Body weight <50 kg (VTE prophylaxis only)
Cautions
- Spinal/epidural hematoma
- Hemorrhage
- Increased bleeding risk in renal impairment and low body weight <50 kg
- Thrombocytopenia
- Not for use as heparin/LMWH substitute for HIT
Adverse reactions
- Bleeding complications
- Mild local injection-site irritation
- Anemia
- Thrombocytopenia
Pregnancy Published data have not reported a clear association with adverse developmental outcomes; low placental transfer observed.
Lactation Undefined
⚠ BOXED WARNING
- Spinal or epidural hematoma with neuraxial anesthesia
Cost, est. cash$4–$300/month
Generic entry2011
Classes and tags
Clinical profile
Legacy pregnancy categoryB
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.
Mechanism of action: Fondaparinux ballicule
