Pharmacology Pharmacodynamics 2

Question 1

A drug that binds to a receptor and produces a submaximal response even at full receptor occupancy is called a:

Accepted Answer

Partial agonist

Answer

A partial agonist has intrinsic efficacy between 0 and 1, so it cannot produce the maximal response even when all receptors are occupied.

Question 2

Which pharmacodynamic parameter describes the concentration of drug required to produce 50% of the maximum effect?

Accepted Answer

EC50

Answer

EC50 (effective concentration 50%) is the drug concentration that produces 50% of the maximal response and is used as a measure of drug potency.

Question 3

An inverse agonist differs from a competitive antagonist in that it:

Accepted Answer

Produces the opposite effect to the agonist by stabilizing the inactive receptor state

Answer

An inverse agonist has negative intrinsic efficacy, stabilizing the inactive conformation of the receptor and producing an effect opposite to the agonist.

Question 4

Tachyphylaxis is best defined as:

Accepted Answer

Rapid decrease in response to a drug after repeated administration in a short time

Answer

Tachyphylaxis is a rapid, short-term reduction in drug response that occurs after repeated or continuous exposure to a drug.

Question 5

Which statement correctly describes a quantal dose-response relationship?

Accepted Answer

It describes the frequency of a defined all-or-none response in a population

Answer

Quantal dose-response curves plot the percentage of a population exhibiting a defined all-or-none endpoint (e.g., death, sleep, seizure) against drug dose.

Pharmacology Practice Test

Pharmacology Practice Test

Pharmacology Pharmacodynamics 2