What is the standard prophylaxis dose of fondaparinux?

• A. 5 mg SQ daily
• B. 7.5 mg SQ daily
• C. 10 mg SQ daily
• D. 2.5 SQ qd

Answer: (D)

Dosing fondaparinux for preventing venous thromboembolism uses a fixed, low amount given once daily. The standard prophylaxis dose is 2.5 mg subcutaneously every day. This consistent dose is chosen to reduce clot risk after surgery without raising the bleeding risk as much as higher, weight-based treatment doses do.

Doses of 5 mg, 7.5 mg, or 10 mg daily are used for treatment of established DVT or PE and are adjusted by weight, not used for routine prophylaxis. Specifically, treatment dosing typically follows weight categories (lower than 50 kg, 50–100 kg, greater than 100 kg) to achieve effective anticoagulation in active thrombosis.