NU 643 Exam 1 V2 | NU 643 Advanced
Psychopharmacology | Actual Q&A with
Rationale (NU643 Exam 1) | Regis
University
1. Which neurotransmitter is primarily associated with the ‘reward’ pathway and is
frequently targeted in treatments for substance use disorders and schizophrenia?
A. Serotonin
B. Dopamine
C. GABA
D. Acetylcholine
Answer: B
Rationale: Dopamine is the primary neurotransmitter involved in the mesolimbic reward
system and executive function. Dysregulation of dopamine pathways is a hallmark of both
schizophrenia and addictive behaviors. Understanding dopamine’s role is essential for
managing psychotropic medications that target these specific neuropsychiatric conditions.
2. A patient is prescribed Fluoxetine and reports significant improvement in depressive
symptoms but experiences new onset insomnia. Which mechanism of action is most likely
responsible?
A. Antagonism of 5-HT2C receptors
,B. Inhibition of the serotonin transporter (SERT)
C. Blockade of H1 histamine receptors
D. Activation of GABA-A receptors
Answer: B
Rationale: Fluoxetine’s primary action is the inhibition of the serotonin transporter
(SERT), which increases synaptic serotonin levels. While therapeutic, elevated serotonin
can stimulate 5-HT2A and 5-HT2C receptors, leading to side effects like insomnia or
agitation. This stimulating effect is particularly noted with Fluoxetine compared to other
SSRIs due to its unique pharmacodynamic profile.
3. When considering the metabolism of psychotropic drugs, which cytochrome P450 enzyme
is responsible for metabolizing approximately 25% of all clinical drugs, including many
antidepressants and antipsychotics?
A. CYP2D6
B. CYP1A2
C. CYP3A4
D. CYP2C19
Answer: A
Rationale: CYP2D6 is a critical enzyme in the metabolism of many psychotropic agents,
including TCAs, SSRIs, and various antipsychotics. Genetic polymorphism in this enzyme
, can lead to significant variation in drug plasma levels among different patients. Identifying
whether a patient is a poor or ultra-rapid metabolizer helps in tailoring dosage to avoid
toxicity or therapeutic failure.
4. Which of the following describes the ‘Inverse Agonist’ effect on a receptor?
A. It binds to the receptor and produces the same effect as the endogenous
neurotransmitter.
B. It binds to the receptor and produces an effect opposite to that of an agonist.
C. It binds to the receptor and blocks the endogenous neurotransmitter from binding.
D. It binds to an allosteric site to enhance the effect of the primary ligand.
Answer: B
Rationale: An inverse agonist binds to the same receptor as an agonist but induces a
pharmacological response opposite to that of the agonist. This requires the receptor to
have constitutive activity (baseline activity in the absence of a ligand). This concept is vital
in psychopharmacology for understanding how certain drugs modulate neurotransmission
beyond simple blockade.
5. The ‘therapeutic window’ of Lithium is narrow. Which of the following plasma levels is
generally considered the standard range for maintenance therapy?
A. 0.6 - 1.2 mEq/L
B. 0.2 - 0.5 mEq/L
C. 1.5 - 2.0 mEq/L
Psychopharmacology | Actual Q&A with
Rationale (NU643 Exam 1) | Regis
University
1. Which neurotransmitter is primarily associated with the ‘reward’ pathway and is
frequently targeted in treatments for substance use disorders and schizophrenia?
A. Serotonin
B. Dopamine
C. GABA
D. Acetylcholine
Answer: B
Rationale: Dopamine is the primary neurotransmitter involved in the mesolimbic reward
system and executive function. Dysregulation of dopamine pathways is a hallmark of both
schizophrenia and addictive behaviors. Understanding dopamine’s role is essential for
managing psychotropic medications that target these specific neuropsychiatric conditions.
2. A patient is prescribed Fluoxetine and reports significant improvement in depressive
symptoms but experiences new onset insomnia. Which mechanism of action is most likely
responsible?
A. Antagonism of 5-HT2C receptors
,B. Inhibition of the serotonin transporter (SERT)
C. Blockade of H1 histamine receptors
D. Activation of GABA-A receptors
Answer: B
Rationale: Fluoxetine’s primary action is the inhibition of the serotonin transporter
(SERT), which increases synaptic serotonin levels. While therapeutic, elevated serotonin
can stimulate 5-HT2A and 5-HT2C receptors, leading to side effects like insomnia or
agitation. This stimulating effect is particularly noted with Fluoxetine compared to other
SSRIs due to its unique pharmacodynamic profile.
3. When considering the metabolism of psychotropic drugs, which cytochrome P450 enzyme
is responsible for metabolizing approximately 25% of all clinical drugs, including many
antidepressants and antipsychotics?
A. CYP2D6
B. CYP1A2
C. CYP3A4
D. CYP2C19
Answer: A
Rationale: CYP2D6 is a critical enzyme in the metabolism of many psychotropic agents,
including TCAs, SSRIs, and various antipsychotics. Genetic polymorphism in this enzyme
, can lead to significant variation in drug plasma levels among different patients. Identifying
whether a patient is a poor or ultra-rapid metabolizer helps in tailoring dosage to avoid
toxicity or therapeutic failure.
4. Which of the following describes the ‘Inverse Agonist’ effect on a receptor?
A. It binds to the receptor and produces the same effect as the endogenous
neurotransmitter.
B. It binds to the receptor and produces an effect opposite to that of an agonist.
C. It binds to the receptor and blocks the endogenous neurotransmitter from binding.
D. It binds to an allosteric site to enhance the effect of the primary ligand.
Answer: B
Rationale: An inverse agonist binds to the same receptor as an agonist but induces a
pharmacological response opposite to that of the agonist. This requires the receptor to
have constitutive activity (baseline activity in the absence of a ligand). This concept is vital
in psychopharmacology for understanding how certain drugs modulate neurotransmission
beyond simple blockade.
5. The ‘therapeutic window’ of Lithium is narrow. Which of the following plasma levels is
generally considered the standard range for maintenance therapy?
A. 0.6 - 1.2 mEq/L
B. 0.2 - 0.5 mEq/L
C. 1.5 - 2.0 mEq/L
