Pharmacokinetics 2

Question 1

In what two phases does drug metabolism mainly occur?

Answer 1

Phase I metabolism

Phase II metabolism

Question 2

Describe phase 1 metabolism

Answer 2

• Generally oxidation, reduction or hydrolysis – Introduce/reveal a reactive chemical group
– “Functionalisation”
• Products often more reactive

Question 3

Describe phase II metabolism

Answer 3

• Synthetic, conjugative reactions

* Hydrophilic, inactive compounds generated (usually)

Question 4

What is the metabolism process for hydrophilic drugs?

Answer 4

Hydrophilic drug molecule
I
V
Kidney 
I
V
Urine

Question 5

What is the metabolism process for hydrophobic drugs?

Answer 5

Two pathways:
Hydrophobic drug molecule 
I
V
Hydrophilic metabolite that either joins the hydrophilic pathway at the kidney or the conjugate pathway as a conjugate

Hydrophobic drug molecule