,NSG 552 Exam 1 - Psychopharmacology - Wilkes
University – (2026–2027) Actual (PDF)
1. A patient with schizophrenia is prescribed a first-generation antipsychotic (FGA). The nurse
practitioner explains that FGAs exert their therapeutic effect primarily through which receptor
mechanism?
A) 5-HT2A receptor antagonism
B) D2 receptor antagonism
C) D1 receptor agonism
D) GABA-A receptor positive allosteric modulation
Correct Answer: D2 receptor antagonism
Rationale: First-generation antipsychotics (FGAs) exert their antipsychotic effect primarily through
potent D2 receptor antagonism in the mesolimbic pathway, reducing positive symptoms of
schizophrenia. 5-HT2A antagonism is more characteristic of second-generation antipsychotics. D1
agonism and GABA modulation are not primary mechanisms of FGAs.
2. The nurse practitioner understands that the cytochrome P450 enzyme responsible for metabolizing
approximately 25% of all psychiatric medications, including many antidepressants and antipsychotics,
is:
A) CYP1A2
B) CYP2D6
C) CYP3A4
D) CYP2C19
Correct Answer: CYP2D6
Rationale: CYP2D6 is a highly polymorphic enzyme that metabolizes approximately 25% of psychiatric
medications. Genetic variations in CYP2D6 can lead to poor or ultrarapid metabolism, affecting drug
efficacy and toxicity. CYP3A4 metabolizes the largest percentage of all drugs overall, but CYP2D6 is
particularly important in psychopharmacology.
3. A patient is prescribed fluoxetine for major depressive disorder. Which pharmacokinetic process
describes the movement of fluoxetine from the gastrointestinal tract into the systemic circulation?
A) Distribution
B) Absorption
,C) Metabolism
D) Excretion
Correct Answer: Absorption
Rationale: Absorption is the process by which a drug moves from its site of administration into the
bloodstream. This process is influenced by the drug's lipid solubility and the pH of the environment.
Understanding absorption is critical for determining the onset of action for psychiatric medications.
4. In signal transduction, the enzyme responsible for the degradation of cyclic adenosine
monophosphate (cAMP) is:
A) Protein Kinase A
B) Adenylate Cyclase
C) Monoamine Oxidase
D) Phosphodiesterase
Correct Answer: Phosphodiesterase
Rationale: Phosphodiesterase breaks down second messengers like cAMP to terminate a signal. By
inhibiting this enzyme, certain drugs can prolong the intracellular effects of neurotransmitters. This
mechanism is central to the action of several pharmacological agents used in mental health.
5. Which enzyme catalyzes the rate-limiting step in the synthesis of serotonin from tryptophan?
A) Aromatic L-amino acid decarboxylase
B) Monoamine oxidase
C) Tryptophan hydroxylase
D) Catechol-O-methyltransferase
Correct Answer: Tryptophan hydroxylase
Rationale: Tryptophan hydroxylase catalyzes the conversion of tryptophan to 5-hydroxytryptophan (5-
HTP), which is the rate-limiting step in serotonin synthesis. Aromatic L-amino acid decarboxylase
converts 5-HTP to serotonin but is not rate-limiting. Monoamine oxidase and COMT are involved in
neurotransmitter degradation.
6. A patient taking fluoxetine reports agitation and muscle twitching. Which neurotransmitter system
is most likely overstimulated?
A) Dopamine
, B) Norepinephrine
C) GABA
D) Serotonin
Correct Answer: Serotonin
Rationale: Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) that increases synaptic
serotonin levels. Excessive serotonin can lead to Serotonin Syndrome, characterized by
neuromuscular excitability, autonomic instability, agitation, and muscle twitching. Clinicians must
assess for hyperreflexia and clonus.
7. Overactivity of which dopamine receptor subtype in the mesolimbic pathway is primarily implicated
in the positive symptoms of schizophrenia?
A) D1 receptor
B) D2 receptor
C) D3 receptor
D) D4 receptor
Correct Answer: D2 receptor
Rationale: The dopamine hypothesis of schizophrenia posits that hyperactivity of D2 receptors in the
mesolimbic pathway (ventral tegmental area to nucleus accumbens) mediates positive symptoms
such as hallucinations and delusions. D1 receptors in the mesocortical pathway are more implicated in
negative and cognitive symptoms.
8. The conversion of tyrosine to L-DOPA is mediated by which enzyme?
A) DOPA decarboxylase
B) Tyrosine hydroxylase
C) Monoamine oxidase
D) Catechol-O-methyltransferase
Correct Answer: Tyrosine hydroxylase
Rationale: Tyrosine hydroxylase catalyzes the conversion of tyrosine to L-DOPA, which is the rate-
limiting step in dopamine synthesis. DOPA decarboxylase converts L-DOPA to dopamine. MAO and
COMT are involved in catecholamine degradation.
University – (2026–2027) Actual (PDF)
1. A patient with schizophrenia is prescribed a first-generation antipsychotic (FGA). The nurse
practitioner explains that FGAs exert their therapeutic effect primarily through which receptor
mechanism?
A) 5-HT2A receptor antagonism
B) D2 receptor antagonism
C) D1 receptor agonism
D) GABA-A receptor positive allosteric modulation
Correct Answer: D2 receptor antagonism
Rationale: First-generation antipsychotics (FGAs) exert their antipsychotic effect primarily through
potent D2 receptor antagonism in the mesolimbic pathway, reducing positive symptoms of
schizophrenia. 5-HT2A antagonism is more characteristic of second-generation antipsychotics. D1
agonism and GABA modulation are not primary mechanisms of FGAs.
2. The nurse practitioner understands that the cytochrome P450 enzyme responsible for metabolizing
approximately 25% of all psychiatric medications, including many antidepressants and antipsychotics,
is:
A) CYP1A2
B) CYP2D6
C) CYP3A4
D) CYP2C19
Correct Answer: CYP2D6
Rationale: CYP2D6 is a highly polymorphic enzyme that metabolizes approximately 25% of psychiatric
medications. Genetic variations in CYP2D6 can lead to poor or ultrarapid metabolism, affecting drug
efficacy and toxicity. CYP3A4 metabolizes the largest percentage of all drugs overall, but CYP2D6 is
particularly important in psychopharmacology.
3. A patient is prescribed fluoxetine for major depressive disorder. Which pharmacokinetic process
describes the movement of fluoxetine from the gastrointestinal tract into the systemic circulation?
A) Distribution
B) Absorption
,C) Metabolism
D) Excretion
Correct Answer: Absorption
Rationale: Absorption is the process by which a drug moves from its site of administration into the
bloodstream. This process is influenced by the drug's lipid solubility and the pH of the environment.
Understanding absorption is critical for determining the onset of action for psychiatric medications.
4. In signal transduction, the enzyme responsible for the degradation of cyclic adenosine
monophosphate (cAMP) is:
A) Protein Kinase A
B) Adenylate Cyclase
C) Monoamine Oxidase
D) Phosphodiesterase
Correct Answer: Phosphodiesterase
Rationale: Phosphodiesterase breaks down second messengers like cAMP to terminate a signal. By
inhibiting this enzyme, certain drugs can prolong the intracellular effects of neurotransmitters. This
mechanism is central to the action of several pharmacological agents used in mental health.
5. Which enzyme catalyzes the rate-limiting step in the synthesis of serotonin from tryptophan?
A) Aromatic L-amino acid decarboxylase
B) Monoamine oxidase
C) Tryptophan hydroxylase
D) Catechol-O-methyltransferase
Correct Answer: Tryptophan hydroxylase
Rationale: Tryptophan hydroxylase catalyzes the conversion of tryptophan to 5-hydroxytryptophan (5-
HTP), which is the rate-limiting step in serotonin synthesis. Aromatic L-amino acid decarboxylase
converts 5-HTP to serotonin but is not rate-limiting. Monoamine oxidase and COMT are involved in
neurotransmitter degradation.
6. A patient taking fluoxetine reports agitation and muscle twitching. Which neurotransmitter system
is most likely overstimulated?
A) Dopamine
, B) Norepinephrine
C) GABA
D) Serotonin
Correct Answer: Serotonin
Rationale: Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) that increases synaptic
serotonin levels. Excessive serotonin can lead to Serotonin Syndrome, characterized by
neuromuscular excitability, autonomic instability, agitation, and muscle twitching. Clinicians must
assess for hyperreflexia and clonus.
7. Overactivity of which dopamine receptor subtype in the mesolimbic pathway is primarily implicated
in the positive symptoms of schizophrenia?
A) D1 receptor
B) D2 receptor
C) D3 receptor
D) D4 receptor
Correct Answer: D2 receptor
Rationale: The dopamine hypothesis of schizophrenia posits that hyperactivity of D2 receptors in the
mesolimbic pathway (ventral tegmental area to nucleus accumbens) mediates positive symptoms
such as hallucinations and delusions. D1 receptors in the mesocortical pathway are more implicated in
negative and cognitive symptoms.
8. The conversion of tyrosine to L-DOPA is mediated by which enzyme?
A) DOPA decarboxylase
B) Tyrosine hydroxylase
C) Monoamine oxidase
D) Catechol-O-methyltransferase
Correct Answer: Tyrosine hydroxylase
Rationale: Tyrosine hydroxylase catalyzes the conversion of tyrosine to L-DOPA, which is the rate-
limiting step in dopamine synthesis. DOPA decarboxylase converts L-DOPA to dopamine. MAO and
COMT are involved in catecholamine degradation.
