Pharmacology Pharmacodynamic Mechanisms 2

Question 1

Which term describes a drug that binds to a receptor and produces a submaximal response regardless of dose?

Accepted Answer

Partial agonist

Answer

A partial agonist has intrinsic efficacy between 0 and 1, so it cannot produce the maximal response even at receptor saturation.

Question 2

An inverse agonist differs from a neutral antagonist in that an inverse agonist:

Accepted Answer

Reduces receptor activity below constitutive baseline

Answer

An inverse agonist stabilizes the inactive receptor conformation, reducing constitutive (basal) receptor activity below the unliganded baseline.

Question 3

The Emax in a dose-response curve represents:

Accepted Answer

The maximum possible effect of a drug

Answer

Emax is the ceiling effect — the greatest response a drug can produce regardless of how much dose is increased.

Question 4

Two drugs are said to be equieffective when they:

Accepted Answer

Require the same dose to achieve any response

Answer

Equieffective doses produce the same magnitude of response and are the basis for comparing drug potency.

Question 5

Receptor reserve (spare receptors) means that:

Accepted Answer

Maximum effect is achieved before all receptors are occupied

Answer

When receptor reserve exists, the system reaches Emax while a fraction of receptors remains unoccupied, allowing the drug to appear more potent than its Kd would predict.

Pharmacology Practice Test

Pharmacology Practice Test

Pharmacology Pharmacodynamic Mechanisms 2