NURS 5334 Quiz 1 Pediatric Prescribing Practice Test with Rationales

NURS 5334 (2262) - Quiz 1 + Pediatric Prescribing
Exercise

Updated 200-Question Practice Test (Answers +
Detailed Rationales After Each Question)

Section 1: Pharmacodynamics
Q1. A drug produces a maximal effect (Emax) that is lower than the endogenous ligand even
when all receptors are occupied. This drug is best classified as:

, A. A full agonist

B. A partial agonist

C. A competitive antagonist

D. An inverse agonist

Correct answer: B

Rationale: Partial agonists have intrinsic activity but cannot produce the same maximal
response as a full agonist, even at high concentrations (they have lower efficacy/Emax).

Key takeaway: Potency is about dose (EC50); efficacy is about max effect (Emax).

Sources: Pharmacodynamics.PartOne.Recorded.Spring2020-English.txt;
Pharmacodynamics.PartTwoRecorded.Spring2020-English.txt;
Pharmacodynamics.PartThree.Recorded.Spring2020-English.txt; Notes - Principles
of Pharmacology 2025.docx



Q2. In a graded dose-response curve, the EC50 represents:

A. The concentration producing 50% receptor occupancy in all cases

B. The maximal effect of the drug

C. The concentration producing 50% of the maximal effect

D. The dose that kills 50% of the population

Correct answer: C

Rationale: EC50 is a graded curve parameter describing potency: the concentration that
produces 50% of that drug’s Emax.

Key takeaway: Lower EC50 = higher potency (assuming same assay/conditions).

Sources: Pharmacodynamics.PartOne.Recorded.Spring2020-English.txt;
Pharmacodynamics.PartTwoRecorded.Spring2020-English.txt;
Pharmacodynamics.PartThree.Recorded.Spring2020-English.txt; Notes - Principles
of Pharmacology 2025.docx

,Q3. Two drugs produce the same Emax, but Drug A reaches 50% effect at a lower concentration
than Drug B. Drug A is:

A. More efficacious

B. A partial agonist

C. Less potent

D. More potent

Correct answer: D

Rationale: If Emax is the same but one drug reaches effect at a lower concentration, that drug is
more potent (left-shifted curve, lower EC50).

Key takeaway: Potency ≠ efficacy.

Sources: Pharmacodynamics.PartOne.Recorded.Spring2020-English.txt;
Pharmacodynamics.PartTwoRecorded.Spring2020-English.txt;
Pharmacodynamics.PartThree.Recorded.Spring2020-English.txt; Notes - Principles
of Pharmacology 2025.docx



Q4. A competitive antagonist added to an agonist typically causes which change on a
graded dose-response curve?

A. Right shift with no change in Emax

B. Left shift with higher Emax

C. Lower Emax with no shift

D. Right shift with lower Emax

Correct answer: A

Rationale: Competitive antagonists compete at the same binding site and can be overcome with
higher agonist concentrations, producing a right shift (increased EC50) but the same Emax.

Key takeaway: Competitive antagonism is surmountable.

Sources: Pharmacodynamics.PartOne.Recorded.Spring2020-English.txt;
Pharmacodynamics.PartTwoRecorded.Spring2020-English.txt;

, Pharmacodynamics.PartThree.Recorded.Spring2020-English.txt; Notes - Principles of
Pharmacology 2025.docx



Q5. An irreversible (noncompetitive) antagonist typically causes which change on a graded
dose-response curve?

A. Right shift with no Emax change

B. Decreased Emax

C. Increased Emax

D. No change in potency or efficacy

Correct answer: B

Rationale: Noncompetitive/irreversible antagonism reduces the number of functional receptors,
which typically lowers the maximal achievable effect (Emax).

Key takeaway: Noncompetitive antagonism is not fully surmountable.

Sources: Pharmacodynamics.PartOne.Recorded.Spring2020-English.txt;
Pharmacodynamics.PartTwoRecorded.Spring2020-English.txt;
Pharmacodynamics.PartThree.Recorded.Spring2020-English.txt; Notes - Principles
of Pharmacology 2025.docx



Q6. Which receptor class directly regulates ion flow across a membrane (fast synaptic signaling)?

A. G-protein coupled receptor

B. Nuclear (intracellular) receptor

C. Enzyme-linked receptor (tyrosine kinase)

D. Ligand-gated ion channel

Correct answer: D

Rationale: Ligand-gated ion channels open/close in response to ligand binding, producing rapid
effects compared with GPCRs or gene transcription pathways.

Key takeaway: Know the four major receptor families.

Sources: Pharmacodynamics.PartOne.Recorded.Spring2020-English.txt;
Pharmacodynamics.PartTwoRecorded.Spring2020-English.txt;