Pharmacology calculations

Question 1

How to calculate volume distribution

Answer 1

Vd = amount in the body (dose) / plasma concentration at time zero

Question 2

How do you calculate clearance?

Answer 2

CL = rate of elimination / concentration

Question 3

What is the equation for calculating elimination of a first order reaction?

Answer 3

Ct = C0e-kt

Question 4

What is the equation relating rate constant, clearance and volume distribution?

Answer 4

CL = k x Vd

Question 5

How do you calculate the infusion rate?

Answer 5

infusion rate = clearance x Css

Question 6

If the drug is only 80% how do you calculate the amount

Answer 6

0.8 x dose

Question 7

What is the equation for bioavailability (F value)?

Answer 7

F = AUC (oral) / AUC (iv)

Question 8

What is the equation for an oral regime?

Answer 8

Dose = CL x Css x t / F

Question 9

How do you work out the dose given with regards to bioavailability ?

Answer 9

dose given = amount needed / F

Question 10

Urgency of onset loading dose equation

Answer 10

LD = Target level x V/D

Question 11

Urgency of onset maintenance dose equation

Answer 11

MD = Target level x CL/F