Inhibits the action of thrombin by binding both to its catalytic site and to its anion-binding exosite. Thrombin is a serine proteinase that plays a central role in the thrombotic process, acting to cleave fibrinogen into fibrin monomers and to activate Factor XIII to Factor XIIIa, allowing fibrin to develop a covalently cross-linked framework which stabilizes the thrombus; thrombin also activates Factors V and VIII, promoting further thrombin generation, and activates platelets, stimulating aggregation and granule release.
Bivalirudin directly and reversibly inhibits thrombin by specifically binding both to the catalytic site and to the anion-binding exosite of circulating and clot-bound thrombin. The action of bivalirudin is reversible because thrombin will slowly cleave the thrombin-bivalirudin bond which recovers the active site of thrombin.
80% proteolytic cleavage
Based on a study by Gleason et al., the no-observed-adverse-effect level (NOAEL) for bivalirudin, administered to rats via intravenous infusion over a 24-hour period, was 2000 mg/kg/24 h.