Bivalirudin (BG-8967) is a reversible inhibitor of α- and ζ-thrombin (Kis = 2.56 and 1.84 nM, respectively), enzymes that exhibit high fibrinogen-clotting activities.

α-thrombin:2.56 nM (Ki, cell free)

0.1 μM hirudin 和 0.1 μM Bivalirudin（即，血浆中 prothrombin 浓度的不到 10%）抑制了 Factor X、Factor V 以及 prothrombin 激活。与 alpha-thrombin 等摩尔以及高出 5 倍的 hirudin 和 hirulog-1 浓度分别消除了外源性 alpha-thrombin 对 Factor V 激活的作用[2]。

在接受阿司匹林治疗的组别中，随着Bivalirudin剂量的低、中、高逐渐增加，沉积量相应地以37%、44%和56%的比例呈剂量依赖性下降。同时，Bivalirudin剂量的增加导致血浆Bivalirudin浓度及激活部分凝血活酶时间比值（最终: 初始）也以剂量依赖的方式上升。血浆Bivalirudin平均浓度在低剂量组为0.74 micrograms/ml，而在高剂量组为2.55 micrograms/ml；对应的激活部分凝血活酶时间比值分别是1.5与3.3[3]。

Animals were randomly assigned to one of five groups: control (no aspirin or hirulog); aspirin alone (10 mg/kg); aspirin plus low-dose hirulog (0.2 mg/kg bolus followed by 0.5 mg/kg/hr); aspirin plus medium-dose hirulog (0.4 mg/kg bolus followed by 1.0 mg/kg/hr); or aspirin plus high-dose hirulog (0.6 mg/kg bolus followed by 1.5 mg/kg/hr). Hirulog was infused before surgery and continued until termination of the experiment 30 minutes after endarterectomy [3].