NR 546 PSYCHOPHARMACOLOGY
ADVANCED FINAL EXAMINATION
QUESTIONS AND ANSWERS
1. Which cytochrome P450 enzyme is most commonly involved in the metabolism of the
majority of psychotropic medications, and what occurs when a strong inhibitor of this
enzyme is introduced?
A. CYP3A4; Drug levels of the substrate increase.
B. CYP2D6; Drug levels of the substrate decrease.
C. CYP1A2; Drug levels of the substrate stay the same.
D. CYP2C19; Drug levels of the substrate decrease.
Answer: A
Conceptual Explanation: CYP3A4 is responsible for metabolizing about 50% of all drugs.
An inhibitor blocks the enzyme, leading to decreased metabolism and increased serum
levels of the substrate.
2. A patient taking Clozapine presents with a Neutrophil count of 900/mm3. According to the
Clozapine REMS program, what is the appropriate clinical action?
A. Continue Clozapine but monitor CBC daily.
,B. Reduce the dose by 50% and recheck in 48 hours.
C. Administer Vitamin B12 and continue therapy.
D. Administer Vitamin B12 and continue therapy.
D. Interrupt Clozapine treatment and consult hematology.
Answer: D
Conceptual Explanation: For Clozapine, an Absolute Neutrophil Count (ANC) below
1000/mm3 (Moderate Neutropenia) requires treatment interruption to prevent
agranulocytosis.
3. Which of the following describes the mechanism of action of Aripiprazole that distinguishes
it from Haloperidol?
A. It is a potent D2 receptor antagonist in all pathways.
B. It is a D2 partial agonist and 5-HT2A antagonist.
C. It acts exclusively on the Mesocortical pathway as an agonist.
D. It is a 5-HT1A antagonist and D2 antagonist.
Answer: B
Conceptual Explanation: Aripiprazole is a D2 partial agonist, which means it stabilizes
dopamine activity, whereas Haloperidol is a pure D2 antagonist.
, 4. A patient prescribed Lithium Carbonate for Bipolar I Disorder presents with coarse tremors,
ataxia, and confusion. What is the most likely serum Lithium level?
A. 0.6 mEq/L
B. 0.9 mEq/L
C. 2.1 mEq/L
D. 1.2 mEq/L
Answer: C
Conceptual Explanation: Serum levels above 1.5 mEq/L indicate toxicity. Coarse tremors,
ataxia, and confusion are signs of moderate to severe toxicity (typically >2.0 mEq/L).
5. When switching a patient from a Tranylcypromine (MAOI) to Fluoxetine (SSRI), how long
must the washout period be to avoid Serotonin Syndrome?
A. 7 days
B. 14 days
C. 21 days
D. 5 weeks
Answer: B
Conceptual Explanation: When switching from an MAOI to an SSRI, a 14-day washout is
required. Note: If switching FROM Fluoxetine TO an MAOI, a 5-week washout is needed due
to Fluoxetine’s long half-life.
ADVANCED FINAL EXAMINATION
QUESTIONS AND ANSWERS
1. Which cytochrome P450 enzyme is most commonly involved in the metabolism of the
majority of psychotropic medications, and what occurs when a strong inhibitor of this
enzyme is introduced?
A. CYP3A4; Drug levels of the substrate increase.
B. CYP2D6; Drug levels of the substrate decrease.
C. CYP1A2; Drug levels of the substrate stay the same.
D. CYP2C19; Drug levels of the substrate decrease.
Answer: A
Conceptual Explanation: CYP3A4 is responsible for metabolizing about 50% of all drugs.
An inhibitor blocks the enzyme, leading to decreased metabolism and increased serum
levels of the substrate.
2. A patient taking Clozapine presents with a Neutrophil count of 900/mm3. According to the
Clozapine REMS program, what is the appropriate clinical action?
A. Continue Clozapine but monitor CBC daily.
,B. Reduce the dose by 50% and recheck in 48 hours.
C. Administer Vitamin B12 and continue therapy.
D. Administer Vitamin B12 and continue therapy.
D. Interrupt Clozapine treatment and consult hematology.
Answer: D
Conceptual Explanation: For Clozapine, an Absolute Neutrophil Count (ANC) below
1000/mm3 (Moderate Neutropenia) requires treatment interruption to prevent
agranulocytosis.
3. Which of the following describes the mechanism of action of Aripiprazole that distinguishes
it from Haloperidol?
A. It is a potent D2 receptor antagonist in all pathways.
B. It is a D2 partial agonist and 5-HT2A antagonist.
C. It acts exclusively on the Mesocortical pathway as an agonist.
D. It is a 5-HT1A antagonist and D2 antagonist.
Answer: B
Conceptual Explanation: Aripiprazole is a D2 partial agonist, which means it stabilizes
dopamine activity, whereas Haloperidol is a pure D2 antagonist.
, 4. A patient prescribed Lithium Carbonate for Bipolar I Disorder presents with coarse tremors,
ataxia, and confusion. What is the most likely serum Lithium level?
A. 0.6 mEq/L
B. 0.9 mEq/L
C. 2.1 mEq/L
D. 1.2 mEq/L
Answer: C
Conceptual Explanation: Serum levels above 1.5 mEq/L indicate toxicity. Coarse tremors,
ataxia, and confusion are signs of moderate to severe toxicity (typically >2.0 mEq/L).
5. When switching a patient from a Tranylcypromine (MAOI) to Fluoxetine (SSRI), how long
must the washout period be to avoid Serotonin Syndrome?
A. 7 days
B. 14 days
C. 21 days
D. 5 weeks
Answer: B
Conceptual Explanation: When switching from an MAOI to an SSRI, a 14-day washout is
required. Note: If switching FROM Fluoxetine TO an MAOI, a 5-week washout is needed due
to Fluoxetine’s long half-life.
