Hepatic Clearance (CLh)

The volume of blood from which a drug is irreversibly removed by the liver per unit time, governed by hepatic blood flow, intrinsic clearance, and protein binding. For high-extraction drugs, hepatic clearance is flow-limited, while for low-extraction drugs, it depends on intrinsic metabolic capacity and free fraction. The well-stirred model is the most commonly used framework for predicting hepatic clearance.

Ví dụ

• Propranolol: high hepatic extraction ratio (~0.7), clearance is flow-dependent
• Warfarin: low extraction ratio (~0.003), clearance depends on intrinsic enzyme activity
• Lidocaine IV: hepatic clearance approximates liver blood flow (~1.5 L/min)