PEBC Pharmacology Basics 2

Question 1

Which pharmacokinetic parameter describes the fraction of an administered drug that reaches systemic circulation unchanged?

Accepted Answer

Bioavailability

Answer

Bioavailability (F) represents the fraction of a drug dose that reaches systemic circulation in an active form after administration.

Question 2

A drug has a narrow therapeutic index. What does this mean clinically?

Accepted Answer

There is a small difference between therapeutic and toxic doses

Answer

A narrow therapeutic index means the toxic dose is only slightly higher than the effective dose, requiring careful monitoring.

Question 3

Which receptor type directly opens an ion channel upon ligand binding?

Accepted Answer

Ionotropic receptor

Answer

Ionotropic receptors (ligand-gated ion channels) directly gate ion channels when a ligand binds, producing rapid effects.

Question 4

What is the primary site of drug metabolism in the body?

Accepted Answer

Liver

Answer

The liver is the primary organ for drug metabolism, containing high concentrations of cytochrome P450 enzymes.

Question 5

A competitive antagonist shifts the agonist dose-response curve in which direction?

Accepted Answer

Right, with no change in Emax

Answer

A competitive antagonist shifts the agonist dose-response curve to the right (higher EC50) but Emax remains unchanged because it can be overcome with more agonist.

PEBC - Pharmacy Examining Board of Canada Practice Test

PEBC - Pharmacy Examining Board of Canada Practice Test

PEBC Pharmacology Basics 2