Wednesday September 9, 2009


Case: A patient requires anticoagulation for PE. The patient has a history of HIT (Heparin Induced Thrombocytopenia), an allergy to Argatroban (per documentation), with a creatinine clearance less than 30ml/min. What is the best available agent for anticoagulation?


Answer: Heparin and LMWHs should not be used due to the history of HIT. The Argatroban allergy is questionable, may be considered, but would rather not take the chance. Fondaparinux (Arixtra) is contraindicated in patients with a creatinine clearance less than 30 ml/min.

Bivalirudin (Angiomax) would be the best available choice, even though it’s not FDA approved for HIT. Bivalirudin is a specific and reversible direct thrombin inhibitor, binding to circulating and clot-bound thrombin. The dose range is 0.05 – 0.15 mg/kg/hr , titrating to maintain aPTT 1.5 – 3 x baseline. It is eliminated renally and via enzymatic processes. An initial dose adjustment should be made if CrCl less than 50 ml/hr to 0.05 mg/kg/hr. Bivalirudin peaks in 1-2 hours, with a half life of 10-24 minutes. Unlike heparin, there are no reversal agents available. The advantage of Bivalirudin is that it may be used in multiorgan failure patients, and those on CVVHD.