NR 546 PSYCHOPHARMACOLOGY
ADVANCED EXAM GUIDE 2026/2027
1. Which cytochrome P450 enzyme is primarily inhibited by Fluoxetine and Paroxetine,
potentially increasing the levels of metoprolol or codeine?
A. CYP3A4
B. CYP1A2
C. CYP2D6
D. CYP2C19
Answer: C
Conceptual Explanation: Fluoxetine and Paroxetine are potent inhibitors of CYP2D6. This
enzyme is responsible for metabolizing many beta-blockers and converting codeine into its
active form, morphine.
2. A patient taking Lithium presents with coarse tremors, ataxia, and confusion. The serum
lithium level is 2.1 mEq/L. What is the most appropriate next step?
A. Hold Lithium and prepare for possible hemodialysis
B. Increase fluid intake and decrease the dose by half
C. Maintain the current dose and retest in 24 hours
,D. Administer activated charcoal immediately
Answer: A
Conceptual Explanation: Lithium levels above 1.5 mEq/L indicate toxicity; levels above
2.0 mEq/L often require hospitalization and consideration of hemodialysis, especially with
neurological symptoms like ataxia and confusion.
3. Which antipsychotic medication requires mandatory monitoring of Absolute Neutrophil
Count (ANC) due to the risk of agranulocytosis?
A. Quetiapine
B. Olanzapine
C. Clozapine
D. Risperidone
Answer: C
Conceptual Explanation: Clozapine is associated with a risk of life-threatening
agranulocytosis. The Clozapine REMS program requires regular ANC monitoring to ensure
the patient’s immune system is stable.
4. What is the primary mechanism of action of Aripiprazole?
A. D2 receptor antagonist
B. Serotonin-Norepinephrine reuptake inhibitor
C. D2 receptor partial agonist
, D. Selective 5-HT2A antagonist
Answer: C
Conceptual Explanation: Aripiprazole is a ‘dopamine stabilizer’ because it acts as a partial
agonist at the D2 receptor, reducing dopamine activity in overactive pathways and
increasing it in underactive ones.
5. Which neurotransmitter pathway is primarily associated with the ‘positive’ symptoms of
schizophrenia, such as hallucinations and delusions?
A. Mesocortical pathway
B. Mesolimbic pathway
C. Tuberoinfundibular pathway
D. Nigrostriatal pathway
Answer: B
Conceptual Explanation: Overactivity of dopamine in the mesolimbic pathway is the
primary biological correlate for positive symptoms in schizophrenia.
6. A patient experiences ‘shuffling gait’ and ‘muscle rigidity’ shortly after starting Haloperidol.
This is likely due to dopamine blockade in which pathway?
A. Nigrostriatal
B. Mesolimbic
C. Mesocortical
ADVANCED EXAM GUIDE 2026/2027
1. Which cytochrome P450 enzyme is primarily inhibited by Fluoxetine and Paroxetine,
potentially increasing the levels of metoprolol or codeine?
A. CYP3A4
B. CYP1A2
C. CYP2D6
D. CYP2C19
Answer: C
Conceptual Explanation: Fluoxetine and Paroxetine are potent inhibitors of CYP2D6. This
enzyme is responsible for metabolizing many beta-blockers and converting codeine into its
active form, morphine.
2. A patient taking Lithium presents with coarse tremors, ataxia, and confusion. The serum
lithium level is 2.1 mEq/L. What is the most appropriate next step?
A. Hold Lithium and prepare for possible hemodialysis
B. Increase fluid intake and decrease the dose by half
C. Maintain the current dose and retest in 24 hours
,D. Administer activated charcoal immediately
Answer: A
Conceptual Explanation: Lithium levels above 1.5 mEq/L indicate toxicity; levels above
2.0 mEq/L often require hospitalization and consideration of hemodialysis, especially with
neurological symptoms like ataxia and confusion.
3. Which antipsychotic medication requires mandatory monitoring of Absolute Neutrophil
Count (ANC) due to the risk of agranulocytosis?
A. Quetiapine
B. Olanzapine
C. Clozapine
D. Risperidone
Answer: C
Conceptual Explanation: Clozapine is associated with a risk of life-threatening
agranulocytosis. The Clozapine REMS program requires regular ANC monitoring to ensure
the patient’s immune system is stable.
4. What is the primary mechanism of action of Aripiprazole?
A. D2 receptor antagonist
B. Serotonin-Norepinephrine reuptake inhibitor
C. D2 receptor partial agonist
, D. Selective 5-HT2A antagonist
Answer: C
Conceptual Explanation: Aripiprazole is a ‘dopamine stabilizer’ because it acts as a partial
agonist at the D2 receptor, reducing dopamine activity in overactive pathways and
increasing it in underactive ones.
5. Which neurotransmitter pathway is primarily associated with the ‘positive’ symptoms of
schizophrenia, such as hallucinations and delusions?
A. Mesocortical pathway
B. Mesolimbic pathway
C. Tuberoinfundibular pathway
D. Nigrostriatal pathway
Answer: B
Conceptual Explanation: Overactivity of dopamine in the mesolimbic pathway is the
primary biological correlate for positive symptoms in schizophrenia.
6. A patient experiences ‘shuffling gait’ and ‘muscle rigidity’ shortly after starting Haloperidol.
This is likely due to dopamine blockade in which pathway?
A. Nigrostriatal
B. Mesolimbic
C. Mesocortical
