What does drug clearance measure?

Question

Clearance describes:

Answer choices

1. The amount of drug removed from the body per unit time.
2. The volume of plasma cleared of the drug per unit time.

Explanation

Clearance measures the efficiency of removing a substance from plasma. Its units are volume/time, such as mL/min or L/h.

CL = elimination rate / plasma concentration. The amount removed per unit time is the elimination rate, which differs from clearance. The volume is theoretical: the measure does not describe the complete purification of a physically separate portion of plasma.