Drug Metabolism and Transport

Question 1

What is a prodrug?

Answer 1

A drug that needs to be metabolized into an active form.

Question 2

Is drug metabolism highly polymorphic?

Answer 2

Yeah

Question 3

In which cellular location are the majority of the CYP450 enzymes found?

Answer 3

Smooth ER (aka microsomal)

Question 4

What is the major organ of drug metabolism?

Answer 4

Liver

Question 5

What are the biggest intrinsic and extrinsic factors regarding drug metabolism, respectively?

Answer 5

Genetics and drug-drug interactions

Question 6

If you are a poor metabolizer, does first pass effect go up or down?

Answer 6

Down

Question 7

If you are a poor metabolizer, does oral bioavailability go up or down?

Answer 7

Up

Question 8

If you are a poor metabolizer, are plasma levels higher or lower? Assume the drug is not a prodrug.

Answer 8

Higher

Question 9

If you are a poor metabolizer, does clearance increase or decrease?

Answer 9

Decrease

Question 10

What are the two phases of drug metabolism and what do they involve?

Answer 10

Phase I: Oxidation or reduction or hydrolysis

Phase II: Glucuronidation or conjugation or methylation

Question 11

Name an important membrane transporter. In which direction does it pump?

Answer 11

p-glycoprotein pumps drugs into the GI lumen for excretion.

Question 12

Which class of enzymes is the most important quantitatively?

Answer 12

CYP3A enzymes.