Treatment of heparin-induced thrombocytopenia: is there a role for bivalirudin?

The recognition and management of heparin-induced thrombocytopenia (HIT) and heparin-induced thrombocytopenia with thrombosis syndrome (HITTS) has been evolving over the past several years. Although HIT is a relatively uncommon adverse event in patients receiving heparin therapy, it bears a significant risk of thrombotic events. If patients are left untreated, 50% can develop thrombosis. Several direct thrombin inhibitors have been studied as alternative anticoagulants in patients with HIT. Lepirudin and argatroban are both approved by the United States Food and Drug Administration (FDA) for the management of HIT. Lepirudin requires dosage adjustments in patients with renal insufficiency and has potential for antibody formation. Argatroban requires dosage adjustments in patients with hepatic insufficiency. Argatroban increases the international normalized ratio when coadministered with warfarin, leading to dosage difficulties when transitioning to warfarin therapy. Bivalirudin is the most recent direct thrombin inhibitor to be introduced to the market, but it is not currently FDA approved for HIT. Controversy still exists over which direct thrombin inhibitor to use, especially in acutely ill patients and in those requiring invasive or surgical procedures. Bivalirudin has a relatively short half-life and a predictable response, which makes it attractive as an anticoagulant in patients requiring invasive or surgical procedures, those who are acutely ill, or patients with both renal and hepatic insufficiency. It offers promise as an additional direct thrombin inhibitor for use in patients with HIT, but additional studies need to be performed to further define its use.