Equations

Question 1

KD

Answer 1

KD= [D][R] / [DR]

Question 2

TI

Answer 2

TI = TD50/ED50

Question 3

CSF

Answer 3

CSF = TD1 / ED99

Question 4

Fick’s Law

Answer 4

[(Cextracellular- Cintracellular) x (area x permeability) ] / thickness

Question 5

H-H equation

Answer 5

pka - pH = log [protonated/unprotonated]

Question 6

Vd

Answer 6

A/C

Question 7

Cockcroft-Gault Equation

Answer 7

Creatinine Clearance = [(140-age) x body wt (kg)] / (serum creatine [mg/dL] x 72)

If female, multiple by 0.85

Question 8

A

Answer 8

A = dose x e ^ (-Ke x t)

Question 9

t (1/2)

Answer 9

t (1/2) = 0.7/ Ke = (0.7 x Vd) / CL

Question 10

CL

Answer 10

Ke x Vd

Question 11

Dm

Answer 11

Dm = CL x C(ss) = Ke x Vd x C(ss)

For intermittent doses: Dm = CL x C(ss) x τ

Dm = (Dm, max/ τ, max) x τ

Question 12

Bioavailability

Answer 12

F = (area under curve of route) / (area under curve of IV)

To correct: IV dose / F

Question 13

Dm, max

Answer 13

Dm, max = (Vd/F) x (C,upper - C,lower)

Question 14

τ, max

Answer 14

τ, max = (ln [C,upper/C,lower]) / Ke