In ACS, fondaparinux dosing is which of the following?

• A. Heparin IV bolus
• B. Enoxaparin SQ
• C. Bivalirudin IV bolus
• D. Fondaparinux 2.5 mg SQ qd x 8 days

Answer: (D)

Fondaparinux dosing in acute coronary syndromes uses a fixed, Xa-inhibiting dose given subcutaneously once daily. The standard amount is 2.5 mg every day, continued for up to 8 days or until hospital discharge. This approach differs from unfractionated heparin given IV, enoxaparin given subcutaneously, or bivalirudin given IV, which are different agents and routes. In practice, if PCI is planned, another anticoagulant (usually UFH) is used during the procedure to prevent catheter-related thrombosis, since fondaparinux alone during PCI can increase that risk. Also, fondaparinux is avoided if kidney function is severely reduced (CrCl <30 mL/min).