Table 5.

Advantages of bivalirudin over heparin

Heparin	Bivalirudin
Indirect thrombin inhibitor Nonspecific binding to: Serine proteases Endothelial cells Action dependent on AT Does not inhibit fibrin-bound protein Causes platelet aggregation Variable PK-PD Risk of HIT	Direct thrombin inhibitor/Does not require cofactors Not inhibited by PF4 or anti-heparin proteins Action independent of AT Inhibits fibrin-bound protein Does not cause platelet aggregation More predictable PK and anticoagulation effect Does not cause thrombocytopenia

Abbreviations: AT, antithrombin; PK-PD, pharmacokinetics-pharmacodynamics; HIT, heparin-induced thrombocytopenia; PF4, platelet factor4; PK, pharmacokinetics.