Bivalirudin

Bivalirudin is an inhibitor of α - and ζ - thrombin (Kis = 2.56 and 1.84 nM, respectively), enzymes that exhibit high fibrinogen - clotting activities. It is selective for α - and ζ - thrombin, lacking activity at trypsin and γ - thrombin, which lacks clotting activity, at a >1,000 - fold excess of bivalirudin. Bivalirudin inhibits α - thrombin - stimulated activation of the clotting factors Factor X, Factor V, and prothrombin in contact - activated plasma at a concentration of 0.1 μM. Administration of bivalirudin (0.5 - 1.5 mg/kg, i.v.) reduces platelet deposition in a rat carotid endarterectomy model in a dose - dependent manner. Formulations containing bivalirudin have been used to prevent ischemic events during angioplasty for thrombus - containing lesions.