NR 546 Psychopharmacology for the Psychiatric-
Mental Health Nurse Practitioner – Chamberlain
College of Nursing – Midterm Exam 2 2026/2027
Question 1: A 34-year-old patient with major depressive disorder is prescribed
an SSRI. The PMHNP explains that the therapeutic effect of SSRIs is most
closely associated with which downstream cellular mechanism?
A. Direct agonism of postsynaptic 5-HT2A receptors
B. Inhibition of monoamine oxidase in the presynaptic terminal
C. Desensitization of presynaptic 5-HT1A autoreceptors leading to enhanced
serotonergic neurotransmission
D. Blockade of voltage-gated sodium channels in the prefrontal cortex
CORRECT ANSWER: C. Desensitization of presynaptic 5-HT1A autoreceptors
leading to enhanced serotonergic neurotransmission
Rationale: SSRIs acutely block the serotonin transporter (SERT), increasing synaptic
serotonin. However, this initial increase activates presynaptic 5-HT1A autoreceptors,
which inhibit further serotonin release. With chronic administration (over 2-4 weeks),
these autoreceptors desensitize. This loss of negative feedback is what allows
serotonergic neurotransmission to fully increase and is believed to be a key mechanism
for the therapeutic effect and explains the delayed onset of action of SSRIs .
Question 2: A patient with schizophrenia is experiencing gynecomastia and
galactorrhea. The PMHNP suspects the antipsychotic medication is
responsible. Which pathway's dopamine D2 receptor blockade most directly
explains this side effect?
A. Mesolimbic pathway
B. Mesocortical pathway
C. Nigrostriatal pathway
D. Tuberoinfundibular pathway
CORRECT ANSWER: D. Tuberoinfundibular pathway
Rationale: The tuberoinfundibular pathway connects the hypothalamus to the anterior
pituitary. Dopamine released in this pathway is the primary prolactin-inhibiting factor
(PIF). D2 receptor blockade by antipsychotics in the anterior pituitary removes this
inhibitory tone, leading to hyperprolactinemia, which can cause gynecomastia,
galactorrhea, and sexual dysfunction .
Question 3: The lipophilicity of a psychotropic medication is a primary
determinant of which pharmacokinetic property?
A. Its affinity for a specific receptor subtype
B. Its ability to cross the blood-brain barrier (BBB)
C. Its rate of metabolism by CYP450 enzymes in the liver
D. Its volume of distribution in adipose tissue
CORRECT ANSWER: B. Its ability to cross the blood-brain barrier (BBB)
,Rationale: The blood-brain barrier is composed of endothelial cells with tight junctions.
For a drug to passively diffuse through these cell membranes and reach its target in the
CNS, it must be lipophilic (fat-soluble). Lipophilic drugs can readily cross the BBB via
passive diffusion, while hydrophilic drugs cannot .
Question 4: A PMHNP is reviewing the mechanism of action of a mood
stabilizer. Which medication's primary mechanism is associated with blocking
voltage-gated sodium channels and inhibiting glutamate release?
A. Lithium carbonate
B. Lamotrigine
C. Valproic acid
D. Carbamazepine
CORRECT ANSWER: B. Lamotrigine
Rationale: Lamotrigine's primary mechanism of action is the blockade of voltage-gated
sodium channels in a use-dependent manner. This inhibits the release of excitatory
neurotransmitters, particularly glutamate, which is thought to be central to its mood-
stabilizing and anticonvulsant effects . While valproic acid and carbamazepine also
affect sodium channels, lamotrigine is most known for this specific glutamate-inhibiting
action.
Question 5: A patient with a known CYP2D6 poor metabolizer phenotype is
prescribed a medication that is a substrate for this enzyme. The PMHNP
should anticipate which clinical outcome?
A. A sub-therapeutic response requiring a higher dose
B. An increased risk of adverse effects at standard doses
C. A faster clearance of the drug from the body
D. No significant difference in drug metabolism
CORRECT ANSWER: B. An increased risk of adverse effects at standard doses
Rationale: CYP2D6 poor metabolizers have reduced or absent enzyme activity. When
a drug is a CYP2D6 substrate, its metabolism is impaired, leading to higher-than-
expected plasma concentrations at standard doses. This significantly increases the risk
of dose-dependent adverse effects and potential toxicity .
Question 6: Which genetic variant screening is most critical to perform before
initiating carbamazepine therapy in a patient of Asian ancestry?
A. CYP2D6
B. CYP3A4
C. HLA-B1502
D. HLA-B5701
CORRECT ANSWER: C. HLA-B*1502
,Rationale: The presence of the HLA-B*1502 allele is a strong genetic risk factor for the
development of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN),
severe and potentially fatal skin reactions, in patients treated with carbamazepine. This
allele is more common in individuals of Asian descent, making screening essential
before initiating therapy in this population .
Question 7: The "neurotrophic hypothesis" of depression posits that the
pathophysiology is linked to:
A. An excess of norepinephrine at the synapse
B. A deficit in GABAergic neurotransmission
C. Reduced BDNF expression leading to hippocampal atrophy
D. An overactivity of the hypothalamic-pituitary-adrenal (HPA) axis
CORRECT ANSWER: C. Reduced BDNF expression leading to hippocampal
atrophy
Rationale: The neurotrophic hypothesis suggests that chronic stress and depression
are associated with a decrease in brain-derived neurotrophic factor (BDNF). This
reduction contributes to impaired neurogenesis and neuronal atrophy, particularly in the
hippocampus. The therapeutic effect of antidepressants is partly attributed to increasing
BDNF and promoting neuroplasticity, which explains the delay in clinical response .
Question 8: A patient presents with symptoms of serotonin syndrome. The
classic triad of symptoms for this condition includes:
A. Fever, bradycardia, and hyporeflexia
B. Miosis, constipation, and urinary retention
C. Tinnitus, ataxia, and nystagmus
D. Mental status changes, autonomic instability, and neuromuscular excitability
CORRECT ANSWER: D. Mental status changes, autonomic instability, and
neuromuscular excitability
Rationale: Serotonin syndrome is a potentially life-threatening condition characterized
by a classic triad of symptoms: altered mental status (agitation, confusion), autonomic
instability (hyperthermia, tachycardia, diaphoresis), and neuromuscular abnormalities
(clonus, hyperreflexia, rigidity) .
Question 9: When switching a patient from fluoxetine to a monoamine oxidase
inhibitor (MAOI), which washout period is required to avoid the risk of
serotonin syndrome?
A. 1 week
B. 2 weeks
C. 5 weeks
D. 24 hours
CORRECT ANSWER: C. 5 weeks
, Rationale: Fluoxetine has a very long half-life (approximately 1-3 days) and its active
metabolite, norfluoxetine, has an even longer half-life (7-15 days). Due to this prolonged
presence in the body, a washout period of 5 weeks is recommended after stopping
fluoxetine before initiating an MAOI to prevent the potentially fatal serotonin syndrome .
Question 10: A PMHNP prescribes low-dose trazodone (25-100 mg) for a
patient. What is the most common primary indication for this medication at
this dose?
A. First-line treatment for major depressive disorder
B. Augmentation of an antipsychotic for schizophrenia
C. Insomnia
D. Bipolar depression
CORRECT ANSWER: C. Insomnia
Rationale: At low doses (25-100 mg), trazodone is a potent histamine H1 and 5-HT2A
antagonist, which produces significant sedative effects. It is widely used off-label as a
sleep aid for insomnia, particularly as an alternative to benzodiazepines and Z-drugs
due to its lower potential for dependence .
Question 11: A patient with bipolar depression is being treated with lithium.
Adding an antidepressant to this regimen carries the most significant risk of:
A. Nephrogenic diabetes insipidus
B. Hyponatremia
C. Switch to mania or hypomania
D. A drug-drug interaction leading to lithium toxicity
CORRECT ANSWER: C. Switch to mania or hypomania
Rationale: One of the major risks of using antidepressant monotherapy in bipolar
disorder is the potential to induce a switch from depression to mania or hypomania.
While all antidepressants carry this risk, it is a critical clinical consideration that must be
weighed carefully when considering an antidepressant for a patient with bipolar
disorder .
Question 12: Which statement best describes the role of a "second messenger"
in neurotransmission?
A. It is the primary neurotransmitter that binds to the postsynaptic receptor.
B. It transports neurotransmitters back into the presynaptic neuron.
C. It amplifies the intracellular signal initiated by a neurotransmitter binding to a
receptor.
D. It degrades monoamines in the synaptic cleft.
CORRECT ANSWER: C. It amplifies the intracellular signal initiated by a
neurotransmitter binding to a receptor.
Mental Health Nurse Practitioner – Chamberlain
College of Nursing – Midterm Exam 2 2026/2027
Question 1: A 34-year-old patient with major depressive disorder is prescribed
an SSRI. The PMHNP explains that the therapeutic effect of SSRIs is most
closely associated with which downstream cellular mechanism?
A. Direct agonism of postsynaptic 5-HT2A receptors
B. Inhibition of monoamine oxidase in the presynaptic terminal
C. Desensitization of presynaptic 5-HT1A autoreceptors leading to enhanced
serotonergic neurotransmission
D. Blockade of voltage-gated sodium channels in the prefrontal cortex
CORRECT ANSWER: C. Desensitization of presynaptic 5-HT1A autoreceptors
leading to enhanced serotonergic neurotransmission
Rationale: SSRIs acutely block the serotonin transporter (SERT), increasing synaptic
serotonin. However, this initial increase activates presynaptic 5-HT1A autoreceptors,
which inhibit further serotonin release. With chronic administration (over 2-4 weeks),
these autoreceptors desensitize. This loss of negative feedback is what allows
serotonergic neurotransmission to fully increase and is believed to be a key mechanism
for the therapeutic effect and explains the delayed onset of action of SSRIs .
Question 2: A patient with schizophrenia is experiencing gynecomastia and
galactorrhea. The PMHNP suspects the antipsychotic medication is
responsible. Which pathway's dopamine D2 receptor blockade most directly
explains this side effect?
A. Mesolimbic pathway
B. Mesocortical pathway
C. Nigrostriatal pathway
D. Tuberoinfundibular pathway
CORRECT ANSWER: D. Tuberoinfundibular pathway
Rationale: The tuberoinfundibular pathway connects the hypothalamus to the anterior
pituitary. Dopamine released in this pathway is the primary prolactin-inhibiting factor
(PIF). D2 receptor blockade by antipsychotics in the anterior pituitary removes this
inhibitory tone, leading to hyperprolactinemia, which can cause gynecomastia,
galactorrhea, and sexual dysfunction .
Question 3: The lipophilicity of a psychotropic medication is a primary
determinant of which pharmacokinetic property?
A. Its affinity for a specific receptor subtype
B. Its ability to cross the blood-brain barrier (BBB)
C. Its rate of metabolism by CYP450 enzymes in the liver
D. Its volume of distribution in adipose tissue
CORRECT ANSWER: B. Its ability to cross the blood-brain barrier (BBB)
,Rationale: The blood-brain barrier is composed of endothelial cells with tight junctions.
For a drug to passively diffuse through these cell membranes and reach its target in the
CNS, it must be lipophilic (fat-soluble). Lipophilic drugs can readily cross the BBB via
passive diffusion, while hydrophilic drugs cannot .
Question 4: A PMHNP is reviewing the mechanism of action of a mood
stabilizer. Which medication's primary mechanism is associated with blocking
voltage-gated sodium channels and inhibiting glutamate release?
A. Lithium carbonate
B. Lamotrigine
C. Valproic acid
D. Carbamazepine
CORRECT ANSWER: B. Lamotrigine
Rationale: Lamotrigine's primary mechanism of action is the blockade of voltage-gated
sodium channels in a use-dependent manner. This inhibits the release of excitatory
neurotransmitters, particularly glutamate, which is thought to be central to its mood-
stabilizing and anticonvulsant effects . While valproic acid and carbamazepine also
affect sodium channels, lamotrigine is most known for this specific glutamate-inhibiting
action.
Question 5: A patient with a known CYP2D6 poor metabolizer phenotype is
prescribed a medication that is a substrate for this enzyme. The PMHNP
should anticipate which clinical outcome?
A. A sub-therapeutic response requiring a higher dose
B. An increased risk of adverse effects at standard doses
C. A faster clearance of the drug from the body
D. No significant difference in drug metabolism
CORRECT ANSWER: B. An increased risk of adverse effects at standard doses
Rationale: CYP2D6 poor metabolizers have reduced or absent enzyme activity. When
a drug is a CYP2D6 substrate, its metabolism is impaired, leading to higher-than-
expected plasma concentrations at standard doses. This significantly increases the risk
of dose-dependent adverse effects and potential toxicity .
Question 6: Which genetic variant screening is most critical to perform before
initiating carbamazepine therapy in a patient of Asian ancestry?
A. CYP2D6
B. CYP3A4
C. HLA-B1502
D. HLA-B5701
CORRECT ANSWER: C. HLA-B*1502
,Rationale: The presence of the HLA-B*1502 allele is a strong genetic risk factor for the
development of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN),
severe and potentially fatal skin reactions, in patients treated with carbamazepine. This
allele is more common in individuals of Asian descent, making screening essential
before initiating therapy in this population .
Question 7: The "neurotrophic hypothesis" of depression posits that the
pathophysiology is linked to:
A. An excess of norepinephrine at the synapse
B. A deficit in GABAergic neurotransmission
C. Reduced BDNF expression leading to hippocampal atrophy
D. An overactivity of the hypothalamic-pituitary-adrenal (HPA) axis
CORRECT ANSWER: C. Reduced BDNF expression leading to hippocampal
atrophy
Rationale: The neurotrophic hypothesis suggests that chronic stress and depression
are associated with a decrease in brain-derived neurotrophic factor (BDNF). This
reduction contributes to impaired neurogenesis and neuronal atrophy, particularly in the
hippocampus. The therapeutic effect of antidepressants is partly attributed to increasing
BDNF and promoting neuroplasticity, which explains the delay in clinical response .
Question 8: A patient presents with symptoms of serotonin syndrome. The
classic triad of symptoms for this condition includes:
A. Fever, bradycardia, and hyporeflexia
B. Miosis, constipation, and urinary retention
C. Tinnitus, ataxia, and nystagmus
D. Mental status changes, autonomic instability, and neuromuscular excitability
CORRECT ANSWER: D. Mental status changes, autonomic instability, and
neuromuscular excitability
Rationale: Serotonin syndrome is a potentially life-threatening condition characterized
by a classic triad of symptoms: altered mental status (agitation, confusion), autonomic
instability (hyperthermia, tachycardia, diaphoresis), and neuromuscular abnormalities
(clonus, hyperreflexia, rigidity) .
Question 9: When switching a patient from fluoxetine to a monoamine oxidase
inhibitor (MAOI), which washout period is required to avoid the risk of
serotonin syndrome?
A. 1 week
B. 2 weeks
C. 5 weeks
D. 24 hours
CORRECT ANSWER: C. 5 weeks
, Rationale: Fluoxetine has a very long half-life (approximately 1-3 days) and its active
metabolite, norfluoxetine, has an even longer half-life (7-15 days). Due to this prolonged
presence in the body, a washout period of 5 weeks is recommended after stopping
fluoxetine before initiating an MAOI to prevent the potentially fatal serotonin syndrome .
Question 10: A PMHNP prescribes low-dose trazodone (25-100 mg) for a
patient. What is the most common primary indication for this medication at
this dose?
A. First-line treatment for major depressive disorder
B. Augmentation of an antipsychotic for schizophrenia
C. Insomnia
D. Bipolar depression
CORRECT ANSWER: C. Insomnia
Rationale: At low doses (25-100 mg), trazodone is a potent histamine H1 and 5-HT2A
antagonist, which produces significant sedative effects. It is widely used off-label as a
sleep aid for insomnia, particularly as an alternative to benzodiazepines and Z-drugs
due to its lower potential for dependence .
Question 11: A patient with bipolar depression is being treated with lithium.
Adding an antidepressant to this regimen carries the most significant risk of:
A. Nephrogenic diabetes insipidus
B. Hyponatremia
C. Switch to mania or hypomania
D. A drug-drug interaction leading to lithium toxicity
CORRECT ANSWER: C. Switch to mania or hypomania
Rationale: One of the major risks of using antidepressant monotherapy in bipolar
disorder is the potential to induce a switch from depression to mania or hypomania.
While all antidepressants carry this risk, it is a critical clinical consideration that must be
weighed carefully when considering an antidepressant for a patient with bipolar
disorder .
Question 12: Which statement best describes the role of a "second messenger"
in neurotransmission?
A. It is the primary neurotransmitter that binds to the postsynaptic receptor.
B. It transports neurotransmitters back into the presynaptic neuron.
C. It amplifies the intracellular signal initiated by a neurotransmitter binding to a
receptor.
D. It degrades monoamines in the synaptic cleft.
CORRECT ANSWER: C. It amplifies the intracellular signal initiated by a
neurotransmitter binding to a receptor.
