Pharmacokinetic Model

IV bolus

(Dose)

Drug
Vd

fm k

Metabolite
Vd(m)

k(m)

(1-fm) k

k(m)=

CLT(m)

Vd(m)
=

0.693

t1/2(m)
  • Dose : The administered dose, mg

  • Dosing interval : The dosing interval, hr

  • Vd : The volume of distribution of the parent drug, liters

  • k = (CLT/Vd) : The first order elimination rate constant of the parent drug, hour -1

  • fm: The fraction of the drug dose that is convened to the metabolite, unitless

  • Vd(m): The volume of distribution of the metabolite, liters

  • k(m) = [CLT(m)/Vd(m)]: The first order elimination rate constant of the metabolite. hour -1