What is the initial infusion rate of bivalirudin for HIT?

• A. 1.0 mg/kg/hr
• B. 0.01 mg/kg/hr
• C. 2.0 mg/kg/hr
• D. 0.15-0.2 mg/kg/hr

Answer: (D)

Direct thrombin inhibitors are used in HIT to provide anticoagulation without heparin. The starting infusion of bivalirudin is 0.15-0.2 mg/kg per hour. This range achieves therapeutic anticoagulation with a short half-life, allowing rapid adjustments if bleeding occurs. The other rates are outside the therapeutic range: 1.0 mg/kg/hr would markedly increase bleeding risk; 0.01 mg/kg/hr would be inadequate for anticoagulation; 2.0 mg/kg/hr is excessively high. Renal function affects dosing, and anticoagulation is guided by monitoring tests like aPTT or ACT.