Excessive Argatroban Anticoagulation for Heparin-Induced Thrombocytopenia

OBJECTIVE:To report 4 patients who became excessively anticoagulated with the recommended or lower starting doses of argatroban during treatment for heparin-induced thrombocytopenia type II (HIT-II) in a cardiothoracic intensive care unit.CASE SUMMARY:Four patients were treated with argatroban after confirmation of HIT-II after cardiac surgery. In 3 patients, argatroban was initiated at the recommended starting dose of 2 μg/kg/min; in 1 patient, therapy was initiated at 1 μg/kg/min. All patients had relatively normal hepatic function. In all cases, the resulting activated partial thromboplastin time was supertherapeutic and exceeded 100 seconds in 3 patients. Additionally, argatroban clearance appeared to be prolonged upon discontinuation.DISCUSSION:Argatroban pharmacokinetics in critically ill patients have not been investigated. Our case series demonstrates the potential over-anticoagulation that can occur in this patient population despite relatively normal hepatic function. An objective causality asse...