WEEK 6

Question 1

The … is the principal organ of drug metabolism.

Answer 1

liver

Question 2

The ……… of the liver cell has very high concentrations of most drug-metabolizing enzymes.

Answer 2

smooth endoplasmic reticulum

Question 3

The … is the first organ perfused by chemicals absorbed in the gut.

Answer 3

liver

Question 4

Other important sites of drug metabolism for some drugs include the gastrointestinal tract, lungs, kidney and the skin. These sites are usually responsible for … metabolic reactions.

Answer 4

localised

Question 5

… is the most common chemical reaction in phase I metabolism.

Answer 5

Oxidation

Question 6

T or F
Both phases of metabolism normally decrease the lipid solubility of the drug, thus increasing the likelihood of its renal or biliary elimination.

Answer 6

T

Question 7

T or F
most lipophobic drugs need to be metabolised to more polar compounds to be excreted.

Answer 7

F
lipophilic

Question 8

Does phase II metabolism of a drug always follow phase I metabolism?

Answer 8

No. Some drugs may ‘bypass’ phase I metabolism and only undergo phase II metabolism directly. Some active metabolites are renally excreted immediately following phase I metabolism. Alternatively, some drugs might undergo multiple steps of phase I metabolism.