Total volume of plasma from which drug is completely removed per unit of time (units = ml/min). May be viewed as a proportionality constant that relates the rate of elimination to Cp.
Rate of Elimination = Cl Cp (1)
Rate of Elimination = (dqT/dt) = qTke (2)
Cl Cp = qTke (3)
Cl = (qTke)/Cp = Vdke (4)
Cl = Dose/AUC
(AUC is area under plasma concentration vs. time curve )
Clearance, ml/min 1500
Rate of elimination, µg/min
500 Volume of distribution, liter
Plasma concentration, mg/liter
This table shows that a rapidly cleared drug (A) can be eliminated slowly if the Cp is low. Drug B is rapidly eliminated even though the clearance is low because the Vd is small and the Cp correspondingly high.