Psychopharmacology Q&A | Psychiatric-Mental Health Nurse
Practitioner
1. Which term describes the study of what the body does to a drug, including absorption,
distribution, metabolism, and excretion?
A) Pharmacodynamics
B) Pharmacokinetics
C) Pharmacogenomics
D) Pharmacotherapeutics
Correct Answer: Pharmacokinetics
Rationale: Pharmacokinetics specifically refers to the movement and processing of drugs within the
body through absorption, distribution, metabolism, and excretion. Pharmacodynamics, by contrast,
describes what the drug does to the body at the receptor level. Understanding this distinction is
foundational to psychopharmacology practice.
2. What is the primary mechanism of action for first-generation antipsychotic medications?
A) Selective serotonin reuptake inhibition
B) Strong dopamine D2 receptor antagonism
C) GABA-A receptor positive allosteric modulation
D) Norepinephrine reuptake blockade
Correct Answer: Strong dopamine D2 receptor antagonism
Rationale: First-generation antipsychotics produce their therapeutic effects primarily through potent
blockade of dopamine D2 receptors in the mesolimbic pathway. This mechanism effectively reduces
positive psychotic symptoms but also causes extrapyramidal symptoms due to D2 blockade in the
nigrostriatal pathway. Second-generation agents have a broader receptor profile.
3. Which antipsychotic medication requires mandatory monitoring of absolute neutrophil count
due to agranulocytosis risk?
A) Risperidone
B) Quetiapine
C) Clozapine
D) Olanzapine
Correct Answer: Clozapine
Rationale: Clozapine carries a black box warning for severe neutropenia and agranulocytosis,
occurring in approximately 1% of patients. The FDA requires enrollment in a REMS program with
,regular ANC monitoring to detect bone marrow suppression early. This monitoring requirement
distinguishes clozapine from all other antipsychotic medications.
4. A patient taking haloperidol develops sudden involuntary muscle contractions causing the
neck to twist and eyes to deviate upward. Which extrapyramidal symptom is this?
A) Akathisia
B) Acute dystonia
C) Tardive dyskinesia
D) Pseudoparkinsonism
Correct Answer: Acute dystonia
Rationale: Acute dystonia presents as sudden, sustained involuntary muscle contractions, often
affecting the neck, jaw, or eyes, and typically emerges within hours to days of initiating antipsychotic
treatment. This reaction is more common with high-potency first-generation agents like haloperidol.
Treatment involves anticholinergic agents such as benztropine.
5. Which dopamine pathway is associated with the therapeutic reduction of positive psychotic
symptoms when D2 receptors are blocked?
A) Nigrostriatal pathway
B) Mesocortical pathway
C) Mesolimbic pathway
D) Tuberoinfundibular pathway
Correct Answer: Mesolimbic pathway
Rationale: The mesolimbic pathway projects from the ventral tegmental area to the nucleus
accumbens and is associated with reward, motivation, and psychosis. Hyperactivity in this pathway is
linked to positive symptoms such as hallucinations and delusions. D2 blockade in this region produces
the desired antipsychotic effect.
6. What is the primary mechanism of action for benzodiazepines in treating anxiety disorders?
A) Inhibition of serotonin reuptake
B) Antagonism of dopamine D2 receptors
C) Positive allosteric modulation of GABA-A receptors
D) Blockade of norepinephrine alpha-1 receptors
Correct Answer: Positive allosteric modulation of GABA-A receptors
Rationale: Benzodiazepines bind to a specific site on the GABA-A receptor complex and enhance the
inhibitory effect of GABA, the primary inhibitory neurotransmitter in the central nervous system. This
increases the frequency of chloride channel opening, producing sedative, anxiolytic, and
anticonvulsant effects. They do not directly activate the receptor but require endogenous GABA.
7. Which neurotransmitter is the primary inhibitory neurotransmitter in the central nervous
system?
,A) Glutamate
B) Dopamine
C) GABA
D) Norepinephrine
Correct Answer: GABA
Rationale: Gamma-aminobutyric acid serves as the principal inhibitory neurotransmitter in the brain,
counterbalancing the excitatory effects of glutamate. Many psychotropic medications, including
benzodiazepines, barbiturates, and certain anticonvulsants, exert their effects by enhancing
GABAergic transmission. A deficiency in GABA activity has been implicated in anxiety disorders.
8. A patient is prescribed a medication that acts as a partial agonist at dopamine D2 receptors.
What is the functional outcome when endogenous dopamine levels are high?
A) Further increase in dopamine signaling
B) No effect due to competitive inhibition
C) Net decrease in dopamine signaling
D) Immediate receptor upregulation
Correct Answer: Net decrease in dopamine signaling
Rationale: A partial agonist has lower intrinsic activity than a full agonist like dopamine. When
endogenous dopamine levels are elevated, the partial agonist competes for receptor occupancy and
produces a net reduction in dopaminergic transmission. Aripiprazole is a clinically relevant example of
this mechanism, which helps stabilize dopamine activity across different pathways.
9. Which cytochrome P450 enzyme is responsible for the metabolism of approximately 25% of
all drugs, including many psychotropic agents?
A) CYP1A2
B) CYP2C19
C) CYP2D6
D) CYP3A4
Correct Answer: CYP2D6
Rationale: CYP2D6 metabolizes a substantial proportion of psychiatric medications, including many
antidepressants and antipsychotics. Genetic polymorphisms in this enzyme can classify patients as
poor, intermediate, extensive, or ultrarapid metabolizers, significantly affecting drug levels and
clinical response. Clinicians must consider CYP2D6 status when selecting medications or encountering
therapeutic failures.
10. What is the primary excitatory neurotransmitter in the central nervous system?
A) GABA
B) Glutamate
, C) Dopamine
D) Serotonin
Correct Answer: Glutamate
Rationale: Glutamate is the most abundant excitatory neurotransmitter in the CNS, playing critical
roles in learning, memory, and synaptic plasticity. Its activity is balanced by the inhibitory effects of
GABA. Glutamatergic dysfunction has been implicated in schizophrenia, depression, and anxiety
disorders, making it a target for emerging psychopharmacological treatments.
11. A patient taking an SSRI reports new-onset confusion, hyperreflexia, and autonomic
instability after adding an herbal supplement. Which supplement most likely caused this
reaction?
A) Acetaminophen
B) St. John's Wort
C) Lorazepam
D) Diphenhydramine
Correct Answer: St. John's Wort
Rationale: St. John's Wort possesses serotonergic properties and can precipitate serotonin syndrome
when combined with SSRIs or other serotonergic agents. Symptoms include altered mental status,
neuromuscular abnormalities, and autonomic dysfunction. Clinicians must routinely screen for herbal
supplement use during medication reconciliation to prevent this potentially life-threatening
interaction.
12. Which medication is most appropriate for acute management of severe agitation in a patient
who refuses oral medications?
A) Oral risperidone
B) Intramuscular haloperidol plus benztropine
C) Oral clozapine
D) Intravenous lithium
Correct Answer: Intramuscular haloperidol plus benztropine
Rationale: For acute agitation when oral medications are refused or impractical, intramuscular
haloperidol provides rapid antipsychotic effect. Benztropine or diphenhydramine is co-administered to
reduce the risk of acute dystonia, which is more likely with high-potency first-generation agents. This
combination is a standard approach in psychiatric emergencies.
13. What is the first-line treatment for antipsychotic-induced akathisia?
A) Benztropine
B) Propranolol
C) Lorazepam
D) Diphenhydramine