NR546 Final Exam Guide | 2025/2026 Edition |
Verifi ed Psychopharmacology Q&A
Domain 1: Foundational Psychopharmacology (Questions 1-25)
Question 1:
A drug that acts as an inverse agonist at a receptor will:
A) Produce the same effect as a neutral antagonist
B) Stabilize the receptor in its inactive state, reducing constitutive activity
C) Block the receptor without affecting baseline activity
D) Activate the receptor to a greater degree than a full agonist
Correct Answer: B
Rationale: An inverse agonist stabilizes a receptor in its inactive conformation, reducing the
baseline (constitutive) activity of the receptor. A neutral antagonist simply blocks agonist
binding without affecting constitutive activity.
Question 2:
The therapeutic effect of selective serotonin reuptake inhibitors (SSRIs) is primarily mediated
by:
A) Upregulation of postsynaptic 5-HT2A receptors
B) Downregulation of presynaptic autoreceptors and desensitization
C) Immediate increase in synaptic serotonin
D) Antagonism of norepinephrine transporters
Correct Answer: B
Rationale: While SSRIs immediately increase synaptic serotonin, the therapeutic lag (2–4
weeks) is due to the time required for presynaptic 5-HT1A autoreceptors to desensitize,
allowing for sustained serotonergic transmission.
Question 3:
A drug with high affinity for the sigma-1 receptor is most likely to be used for:
A) Antipsychotic effects
B) Cognitive enhancement in depression
C) Induction of anesthesia
D) Treatment of narcolepsy
Correct Answer: B
,Rationale: Sigma-1 receptor agonism is associated with neuroplasticity, neuroprotection,
and cognitive enhancement. Fluvoxamine is an SSRI with high sigma-1 affinity, and this
property is thought to contribute to its cognitive benefits in depression.
Question 4:
Which pharmacokinetic parameter represents the time required for a drug to reach its
maximum concentration in the plasma?
A) Half-life (t½)
B) Area under the curve (AUC)
C) Time to peak (Tmax)
D) Volume of distribution (Vd)
Correct Answer: C
Rationale: Tmax is the time at which the maximum serum concentration (Cmax) is achieved.
This parameter is influenced by absorption rate.
Question 5:
A patient is a poor metabolizer (PM) of CYP2D6 substrates. Which of the following is most
likely to occur when this patient takes a drug metabolized by CYP2D6?
A) Reduced drug efficacy
B) Increased risk of adverse effects at standard doses
C) Faster clearance of the drug
D) Reduced half-life
Correct Answer: B
Rationale: Poor metabolizers have reduced or absent CYP2D6 enzyme activity, leading to
higher serum concentrations and prolonged half-life of CYP2D6 substrates, increasing the
risk of dose-dependent adverse effects.
Question 6:
Which of the following best describes pharmacodynamics?
A) The study of drug absorption, distribution, metabolism, and excretion
B) The study of what the drug does to the body, including receptor binding and effects
C) The genetic variations that affect drug metabolism
D) The process of drug formulation and delivery
Correct Answer: B
Rationale: Pharmacodynamics refers to the biochemical and physiological effects of drugs
on the body, including receptor interactions, signal transduction, and dose-response
relationships.
,Question 7:
A drug that is a weak base (pKa 8.4) will be most rapidly absorbed in which part of the
gastrointestinal tract?
A) Stomach (pH 1.5–3.5)
B) Duodenum (pH 5–6)
C) Jejunum (pH 6–7)
D) Ileum (pH 7–8)
Correct Answer: D
Rationale: Weak bases are more lipid-soluble and better absorbed in environments where
they are un-ionized. In basic pH (ileum, pH 7–8), a weak base with pKa 8.4 will be
predominantly un-ionized, facilitating absorption.
Question 8:
The volume of distribution (Vd) of a drug is 500 L. This suggests that the drug:
A) Is highly protein-bound
B) Is primarily confined to the vascular space
C) Is extensively distributed into tissues
D) Has poor bioavailability
Correct Answer: C
Rationale: A very large Vd (greater than total body water, ~42 L) indicates that the drug is
extensively sequestered in tissues, often due to high lipophilicity or tissue binding.
Question 9:
Which of the following drug interactions is primarily pharmacokinetic?
A) Additive sedation from two CNS depressants
B) Antagonism of warfarin by vitamin K
C) Inhibition of CYP3A4 by ketoconazole, increasing simvastatin levels
D) Synergistic antihypertensive effects of two agents
Correct Answer: C
Rationale: Pharmacokinetic interactions involve changes in drug absorption, distribution,
metabolism, or excretion. CYP enzyme inhibition is a classic pharmacokinetic interaction.
Question 10:
The blood-brain barrier (BBB) limits drug entry into the CNS primarily due to:
A) High lipid solubility of most psychotropic drugs
B) Tight junctions between endothelial cells and efflux transporters like P-glycoprotein
C) Low protein binding in the cerebral circulation
, D) Rapid metabolism by cerebral monoamine oxidase
Correct Answer: B
Rationale: The BBB is formed by tight junctions of endothelial cells and the presence of
efflux transporters (e.g., P-glycoprotein) that actively pump drugs back into the bloodstream.
Question 11:
A drug with a narrow therapeutic index requires:
A) Less frequent monitoring of serum levels
B) Careful titration and therapeutic drug monitoring
C) No adjustment for renal impairment
D) Loading dose only
Correct Answer: B
Rationale: Narrow therapeutic index drugs (e.g., lithium, valproate, carbamazepine) have a
small margin between therapeutic and toxic doses, necessitating careful titration and
routine monitoring of serum concentrations.
Question 12:
Which cytochrome P450 enzyme is most commonly involved in drug-drug interactions due
to its high abundance and susceptibility to inhibition?
A) CYP1A2
B) CYP2C19
C) CYP2D6
D) CYP3A4
Correct Answer: D
Rationale: CYP3A4 is responsible for metabolizing approximately 50% of all marketed drugs.
It is highly susceptible to inhibition (e.g., by ketoconazole, grapefruit juice) and induction
(e.g., by carbamazepine, rifampin).
Question 13:
A full agonist at a G-protein-coupled receptor (GPCR) will:
A) Produce a maximal response by activating the receptor
B) Block the receptor without activating it
C) Produce a submaximal response even at full receptor occupancy
D) Reverse the activity of an inverse agonist
Correct Answer: A
Verifi ed Psychopharmacology Q&A
Domain 1: Foundational Psychopharmacology (Questions 1-25)
Question 1:
A drug that acts as an inverse agonist at a receptor will:
A) Produce the same effect as a neutral antagonist
B) Stabilize the receptor in its inactive state, reducing constitutive activity
C) Block the receptor without affecting baseline activity
D) Activate the receptor to a greater degree than a full agonist
Correct Answer: B
Rationale: An inverse agonist stabilizes a receptor in its inactive conformation, reducing the
baseline (constitutive) activity of the receptor. A neutral antagonist simply blocks agonist
binding without affecting constitutive activity.
Question 2:
The therapeutic effect of selective serotonin reuptake inhibitors (SSRIs) is primarily mediated
by:
A) Upregulation of postsynaptic 5-HT2A receptors
B) Downregulation of presynaptic autoreceptors and desensitization
C) Immediate increase in synaptic serotonin
D) Antagonism of norepinephrine transporters
Correct Answer: B
Rationale: While SSRIs immediately increase synaptic serotonin, the therapeutic lag (2–4
weeks) is due to the time required for presynaptic 5-HT1A autoreceptors to desensitize,
allowing for sustained serotonergic transmission.
Question 3:
A drug with high affinity for the sigma-1 receptor is most likely to be used for:
A) Antipsychotic effects
B) Cognitive enhancement in depression
C) Induction of anesthesia
D) Treatment of narcolepsy
Correct Answer: B
,Rationale: Sigma-1 receptor agonism is associated with neuroplasticity, neuroprotection,
and cognitive enhancement. Fluvoxamine is an SSRI with high sigma-1 affinity, and this
property is thought to contribute to its cognitive benefits in depression.
Question 4:
Which pharmacokinetic parameter represents the time required for a drug to reach its
maximum concentration in the plasma?
A) Half-life (t½)
B) Area under the curve (AUC)
C) Time to peak (Tmax)
D) Volume of distribution (Vd)
Correct Answer: C
Rationale: Tmax is the time at which the maximum serum concentration (Cmax) is achieved.
This parameter is influenced by absorption rate.
Question 5:
A patient is a poor metabolizer (PM) of CYP2D6 substrates. Which of the following is most
likely to occur when this patient takes a drug metabolized by CYP2D6?
A) Reduced drug efficacy
B) Increased risk of adverse effects at standard doses
C) Faster clearance of the drug
D) Reduced half-life
Correct Answer: B
Rationale: Poor metabolizers have reduced or absent CYP2D6 enzyme activity, leading to
higher serum concentrations and prolonged half-life of CYP2D6 substrates, increasing the
risk of dose-dependent adverse effects.
Question 6:
Which of the following best describes pharmacodynamics?
A) The study of drug absorption, distribution, metabolism, and excretion
B) The study of what the drug does to the body, including receptor binding and effects
C) The genetic variations that affect drug metabolism
D) The process of drug formulation and delivery
Correct Answer: B
Rationale: Pharmacodynamics refers to the biochemical and physiological effects of drugs
on the body, including receptor interactions, signal transduction, and dose-response
relationships.
,Question 7:
A drug that is a weak base (pKa 8.4) will be most rapidly absorbed in which part of the
gastrointestinal tract?
A) Stomach (pH 1.5–3.5)
B) Duodenum (pH 5–6)
C) Jejunum (pH 6–7)
D) Ileum (pH 7–8)
Correct Answer: D
Rationale: Weak bases are more lipid-soluble and better absorbed in environments where
they are un-ionized. In basic pH (ileum, pH 7–8), a weak base with pKa 8.4 will be
predominantly un-ionized, facilitating absorption.
Question 8:
The volume of distribution (Vd) of a drug is 500 L. This suggests that the drug:
A) Is highly protein-bound
B) Is primarily confined to the vascular space
C) Is extensively distributed into tissues
D) Has poor bioavailability
Correct Answer: C
Rationale: A very large Vd (greater than total body water, ~42 L) indicates that the drug is
extensively sequestered in tissues, often due to high lipophilicity or tissue binding.
Question 9:
Which of the following drug interactions is primarily pharmacokinetic?
A) Additive sedation from two CNS depressants
B) Antagonism of warfarin by vitamin K
C) Inhibition of CYP3A4 by ketoconazole, increasing simvastatin levels
D) Synergistic antihypertensive effects of two agents
Correct Answer: C
Rationale: Pharmacokinetic interactions involve changes in drug absorption, distribution,
metabolism, or excretion. CYP enzyme inhibition is a classic pharmacokinetic interaction.
Question 10:
The blood-brain barrier (BBB) limits drug entry into the CNS primarily due to:
A) High lipid solubility of most psychotropic drugs
B) Tight junctions between endothelial cells and efflux transporters like P-glycoprotein
C) Low protein binding in the cerebral circulation
, D) Rapid metabolism by cerebral monoamine oxidase
Correct Answer: B
Rationale: The BBB is formed by tight junctions of endothelial cells and the presence of
efflux transporters (e.g., P-glycoprotein) that actively pump drugs back into the bloodstream.
Question 11:
A drug with a narrow therapeutic index requires:
A) Less frequent monitoring of serum levels
B) Careful titration and therapeutic drug monitoring
C) No adjustment for renal impairment
D) Loading dose only
Correct Answer: B
Rationale: Narrow therapeutic index drugs (e.g., lithium, valproate, carbamazepine) have a
small margin between therapeutic and toxic doses, necessitating careful titration and
routine monitoring of serum concentrations.
Question 12:
Which cytochrome P450 enzyme is most commonly involved in drug-drug interactions due
to its high abundance and susceptibility to inhibition?
A) CYP1A2
B) CYP2C19
C) CYP2D6
D) CYP3A4
Correct Answer: D
Rationale: CYP3A4 is responsible for metabolizing approximately 50% of all marketed drugs.
It is highly susceptible to inhibition (e.g., by ketoconazole, grapefruit juice) and induction
(e.g., by carbamazepine, rifampin).
Question 13:
A full agonist at a G-protein-coupled receptor (GPCR) will:
A) Produce a maximal response by activating the receptor
B) Block the receptor without activating it
C) Produce a submaximal response even at full receptor occupancy
D) Reverse the activity of an inverse agonist
Correct Answer: A
