Pharmacology equations

Question 1

volume of distribution

Answer 1

Vd= (amount of drug given)/ (plasma concentration of drug)= D/C

Question 2

clearance

Answer 2

CL= Rate of elimination/ plasma concentration
= (0.7 x Vd)/ t1/2
= K*Vd

Question 3

loading dose

Answer 3

LD= (steady state concentration) (volume of distribution)= LD= CssVd

Question 4

maintenance dose

Answer 4

MD= Css*CL

maintenance dose is not affected by volume of distribution

Question 5

Bioavailability (F)

Answer 5

4 half lives for 94% of steady state level of drug to be eliminated

1 half- life: 50% eliminated/50% remaining
2 half- lives: 75% eliminated/ 25% remaining
3 half- lives: 86.5% eliminated/ 12.5% remaining
4 half- lives: 94% eliminated/ 6.35% remaining