fondaparinux
Brand: Arixtra
ISMP High Alert Prototype Drug
Drug Class: anticoagulant
Drug Family: anticoagulant
Subclass: synthetic pentasaccharide factor Xa inhibitor
Organ Systems: cardiovascularhematology-oncology
Mechanism of Action
Synthetic pentasaccharide that selectively binds AT-III, accelerating only Xa inhibition; too short to bridge thrombin; no activity against IIa.
factor Xa (via AT-III, selective)
Indications
- DVT/PE treatment and prevention
- ACS (NSTEMI)
- HIT management (alternative)
Contraindications
- severe renal impairment (CrCl <30)
- active bleeding
- bacterial endocarditis
Adverse Effects
Common
- bleeding
- injection site reactions
Serious
- major hemorrhage
Pharmacokinetics (ADME)
| Absorption | 100% SC bioavailability |
| Distribution | mostly intravascular |
| Metabolism | not metabolized |
| Excretion | renal unchanged |
| Half-life | 17-21 hours |
| Onset | 2 hours SC |
| Peak | 2-3 hours |
| Duration | 24 hours |
| Protein Binding | 94-97% |
| Vd | 7-11 L |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| antiplatelet agents | increased bleeding | major |
Nursing Considerations
- No antidote (protamine does not bind — no reversal agent available)
- HIT-safe: does not bind PF4 (too short)
- Once-daily SC injection
- Renal clearance only — dose-adjust for CrCl
Clinical Pearls
- HIT-safe: pentasaccharide too short to bind PF4; no cross-reactivity with HIT antibodies
- No antidote: manage bleeding with supportive care and time (17-21h half-life)
- OASIS-5: as effective as enoxaparin in NSTEMI with less bleeding
Safety Profile
Pregnancy use-with-caution
Lactation use-with-caution
Renal Adjustment Required
Hepatic Adjustment Not required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.