NSG 552 WILKES
PSYCHOPHARMACOLOGY
COMPREHENSIVE EXAM QUESTIONS
AND ANSWERS
1. Which cytochrome P450 enzyme is responsible for the metabolism of approximately 25%
of all psychiatric medications, and is notably inhibited by fluoxetine and paroxetine?
A. CYP2D6
B. CYP3A4
C. CYP1A2
D. CYP2C19
Answer: A
Conceptual Explanation: CYP2D6 is a major metabolic pathway for many antidepressants
and antipsychotics. Fluoxetine and paroxetine are potent inhibitors, which can lead to
increased serum levels of co-administered substrates like TCAs or certain antipsychotics.
2. In the treatment of schizophrenia, the ‘mesolimbic dopamine hypothesis’ suggests that
positive symptoms are primarily caused by:
A. Dopamine excess in the nucleus accumbens
,B. Dopamine deficiency in the prefrontal cortex
C. Serotonin excess in the basal ganglia
D. Glutamate deficiency in the hippocampus
Answer: A
Conceptual Explanation: The mesolimbic pathway projects from the ventral tegmental
area to the nucleus accumbens; overactivity (excess dopamine) in this region is associated
with positive symptoms like hallucinations and delusions.
3. Which of the following describes the mechanism of action of Buspirone (Buspar)?
A. GABA-A receptor positive allosteric modulator
B. Norepinephrine reuptake inhibitor
C. Alpha-2 delta subunit calcium channel blocker
D. 5-HT1A receptor partial agonist
Answer: D
Conceptual Explanation: Buspirone is a 5-HT1A partial agonist used primarily for
Generalized Anxiety Disorder. It does not possess the sedative or addictive properties of
benzodiazepines.
4. A patient taking Clozapine presents with an Absolute Neutrophil Count (ANC) of 900/mm³.
According to REMS guidelines, what is the appropriate action?
A. Interrupt treatment and consult a hematologist
, B. Reduce the dose by 50% and retest in 48 hours
C. Continue treatment but monitor ANC weekly
D. Increase the dose to compensate for metabolic shift
Answer: A
Conceptual Explanation: For a general population patient, an ANC below 1000/mm³ is
classified as moderate neutropenia, requiring treatment interruption and hematology
consultation per Clozapine REMS protocols.
5. What is the primary mechanism by which Valproic Acid (Depakote) may cause neural tube
defects in a developing fetus?
A. Inhibition of dihydrofolate reductase
B. Antagonism of Vitamin K-dependent clotting factors
C. Interference with folate metabolism and HDAC inhibition
D. Direct neurotoxicity to the fetal pons
Answer: C
Conceptual Explanation: Valproic acid interferes with folate metabolism and acts as a
histone deacetylase (HDAC) inhibitor, significantly increasing the risk of spina bifida and
other neural tube defects.
PSYCHOPHARMACOLOGY
COMPREHENSIVE EXAM QUESTIONS
AND ANSWERS
1. Which cytochrome P450 enzyme is responsible for the metabolism of approximately 25%
of all psychiatric medications, and is notably inhibited by fluoxetine and paroxetine?
A. CYP2D6
B. CYP3A4
C. CYP1A2
D. CYP2C19
Answer: A
Conceptual Explanation: CYP2D6 is a major metabolic pathway for many antidepressants
and antipsychotics. Fluoxetine and paroxetine are potent inhibitors, which can lead to
increased serum levels of co-administered substrates like TCAs or certain antipsychotics.
2. In the treatment of schizophrenia, the ‘mesolimbic dopamine hypothesis’ suggests that
positive symptoms are primarily caused by:
A. Dopamine excess in the nucleus accumbens
,B. Dopamine deficiency in the prefrontal cortex
C. Serotonin excess in the basal ganglia
D. Glutamate deficiency in the hippocampus
Answer: A
Conceptual Explanation: The mesolimbic pathway projects from the ventral tegmental
area to the nucleus accumbens; overactivity (excess dopamine) in this region is associated
with positive symptoms like hallucinations and delusions.
3. Which of the following describes the mechanism of action of Buspirone (Buspar)?
A. GABA-A receptor positive allosteric modulator
B. Norepinephrine reuptake inhibitor
C. Alpha-2 delta subunit calcium channel blocker
D. 5-HT1A receptor partial agonist
Answer: D
Conceptual Explanation: Buspirone is a 5-HT1A partial agonist used primarily for
Generalized Anxiety Disorder. It does not possess the sedative or addictive properties of
benzodiazepines.
4. A patient taking Clozapine presents with an Absolute Neutrophil Count (ANC) of 900/mm³.
According to REMS guidelines, what is the appropriate action?
A. Interrupt treatment and consult a hematologist
, B. Reduce the dose by 50% and retest in 48 hours
C. Continue treatment but monitor ANC weekly
D. Increase the dose to compensate for metabolic shift
Answer: A
Conceptual Explanation: For a general population patient, an ANC below 1000/mm³ is
classified as moderate neutropenia, requiring treatment interruption and hematology
consultation per Clozapine REMS protocols.
5. What is the primary mechanism by which Valproic Acid (Depakote) may cause neural tube
defects in a developing fetus?
A. Inhibition of dihydrofolate reductase
B. Antagonism of Vitamin K-dependent clotting factors
C. Interference with folate metabolism and HDAC inhibition
D. Direct neurotoxicity to the fetal pons
Answer: C
Conceptual Explanation: Valproic acid interferes with folate metabolism and acts as a
histone deacetylase (HDAC) inhibitor, significantly increasing the risk of spina bifida and
other neural tube defects.
