Equations

Question 1

1/2 Life

Answer 1

T1/2 = (.693*Vd)/Cl

Question 2

Clearance

Answer 2

Rate of elimination/Plasma Concentration

=Vd*Ke (elimination constant)

or Cl= (.693*Vd)/T1/2

Volume cleared of drug/time = clearance

Question 3

Loading Dose

Answer 3

Loading dose = (Cp * Vd)/F
so if 100% bio –> LD = Concentration you want * Volume its going in

In renal/liver disease: Maintenance dose decreases, but not loading dose

Cp = Target plasma concentration at steady state (4-5) half lives)
t = dosage interval, if not continuous
F=bioavailability

Question 4

Maintenance Dose

Answer 4

MD= CpCLt)/F
So clearance times concentration you want

Cp = Target plasma concentration at steady state (4-5) half lives)
t = dosage interval, if not continuous
F=bioavailability