Anticoagulant activity of excess protamine administration during reversal of heparin-induced anticoagulation. (A) Protamine (10-80 μg/mL) was titrated into normal pooled plasma containing 0.3 U/mL (●) or 1.0 U/mL (○) UFH, and TF-initiated thrombin generation was determined as before. (B) The ability of protamine (10-80 μg/mL) to reverse different LMWH preparations of 1.0 U/mL tinzaparin (●) or 1.0 U/mL enoxaparin (▼) was also characterized.