ADME intro

Question 1

What is absorption?

Answer 1

All processes from site of administration to site of measurement

Question 2

What is Bio-availability?

Answer 2

defined here as a measure of the extent of

absorption of unchanged administered compound

Question 3

What is distribution?

Answer 3

Reversible transfer of substance between site of measurement and other sites within the body

Question 4

What is metabolism?

Answer 4

Irreversible loss of unchanged substance by chemical conversion (alters physchem properties of the drug)

Question 5

What is excretion?

Answer 5

Irreversible loss of unchanged substance

Question 6

What is elimination?

Answer 6

Irreversible loss of unchanged substance from site of measurement

Question 7

What is disposition?

Answer 7

Elimination and distribution

Question 8

What is pharmacokinetic behaviour a function of?

Answer 8

o Physicochemical and structural properties of drug
o Dosage form
o Route of drug administration – i.v., oral, i.m.
o Physiology of the body

Question 9

What factors influence the pharmacokinetic properties of a drug?

Answer 9

o	Genetics
o	Size
o	Age
o	Disease
o	Co-administration of other drugs 
o	Environmental factors (e.g. smoking)

Question 10

What types of PK models are there for the ADME process?

Answer 10

1. Single equation - integrated C = C0e-kt or differential
2. Kinetic compartmental models
   • number of compartments defined by the data
   • often used for fitting of sparse clinical data – population PK modelling
3. Physiologically-based PK models
   a. Major tool for predicting in vivo pharmacokinetics from in vitro data (Simulation workshops)