NU 643 Exam 1 V1 | NU 643 Advanced
Psychopharmacology | Actual Q&A with
Rationale (NU643 Exam 1) | Regis
University
1. A 28-year-old male with schizophrenia is prescribed Haloperidol. He presents with acute
muscle spasms of the neck and back. Which mechanism is primarily responsible for this
extrapyramidal symptom?
A. Norepinephrine reuptake inhibition in the locus coeruleus
B. Muscarinic M1 receptor blockade in the frontal cortex
C. Serotonin 5-HT2A receptor antagonism in the mesocortical tract
D. Dopamine D2 receptor antagonism in the nigrostriatal pathway
Answer: D
Rationale: Acute dystonia results from the blockade of D2 receptors in the nigrostriatal
dopamine pathway. This pathway is responsible for controlling motor movements and
posture. When typical antipsychotics like Haloperidol reduce dopamine activity here, an
imbalance between dopamine and acetylcholine occurs, leading to involuntary muscle
contractions. Effective management often involves anticholinergic medications like
benztropine.
,2. Which cytochrome P450 enzyme is primarily induced by cigarette smoking, potentially
requiring higher doses of Olanzapine or Clozapine?
A. CYP1A2
B. CYP3A4
C. CYP2D6
D. CYP2C19
Answer: A
Rationale: Cigarette smoke contains polycyclic aromatic hydrocarbons that act as potent
inducers of the CYP1A2 enzyme. Induction of this enzyme increases the metabolism of
drugs like olanzapine and clozapine, leading to lower serum concentrations. If a patient
stops smoking abruptly while on these medications, levels may rise to toxic ranges,
necessitating careful monitoring and dose adjustment.
3. A patient taking Phenelzine (an MAOI) consumes a large amount of aged cheese and wine.
What is the most likely pathological outcome of this interaction?
A. Hypotensive crisis due to volume depletion
B. Serotonin syndrome due to excessive 5-HT
C. Hypertensive crisis due to tyramine accumulation
D. Neuroleptic malignant syndrome
Answer: C
, Rationale: Tyramine is an amino acid normally metabolized by Monoamine Oxidase (MAO)
in the gut. When MAOIs inhibit this process, tyramine enters the systemic circulation and
triggers a massive release of stored norepinephrine from sympathetic nerve terminals.
This results in severe vasoconstriction and a dangerous rise in blood pressure, known as a
hypertensive crisis.
4. The ‘therapeutic window’ for Lithium is narrow. Which of the following serum ranges is
generally considered therapeutic for acute mania?
A. 0.2 to 0.5 mEq/L
B. 2.5 to 3.5 mEq/L
C. 1.5 to 2.0 mEq/L
D. 0.8 to 1.2 mEq/L
Answer: D
Rationale: For the treatment of acute manic episodes, a lithium level of 0.8 to 1.2 mEq/L is
the standard target. Maintenance levels are typically lower, ranging from 0.6 to 1.0 mEq/L
to reduce long-term side effects. Monitoring is critical because toxicity can occur at levels
as low as 1.5 mEq/L, leading to neurological and renal complications.
5. A patient is prescribed Fluoxetine for depression. How long is the washout period required
before starting an MAOI to avoid serotonin syndrome?
A. 5 weeks
B. 1 week
Psychopharmacology | Actual Q&A with
Rationale (NU643 Exam 1) | Regis
University
1. A 28-year-old male with schizophrenia is prescribed Haloperidol. He presents with acute
muscle spasms of the neck and back. Which mechanism is primarily responsible for this
extrapyramidal symptom?
A. Norepinephrine reuptake inhibition in the locus coeruleus
B. Muscarinic M1 receptor blockade in the frontal cortex
C. Serotonin 5-HT2A receptor antagonism in the mesocortical tract
D. Dopamine D2 receptor antagonism in the nigrostriatal pathway
Answer: D
Rationale: Acute dystonia results from the blockade of D2 receptors in the nigrostriatal
dopamine pathway. This pathway is responsible for controlling motor movements and
posture. When typical antipsychotics like Haloperidol reduce dopamine activity here, an
imbalance between dopamine and acetylcholine occurs, leading to involuntary muscle
contractions. Effective management often involves anticholinergic medications like
benztropine.
,2. Which cytochrome P450 enzyme is primarily induced by cigarette smoking, potentially
requiring higher doses of Olanzapine or Clozapine?
A. CYP1A2
B. CYP3A4
C. CYP2D6
D. CYP2C19
Answer: A
Rationale: Cigarette smoke contains polycyclic aromatic hydrocarbons that act as potent
inducers of the CYP1A2 enzyme. Induction of this enzyme increases the metabolism of
drugs like olanzapine and clozapine, leading to lower serum concentrations. If a patient
stops smoking abruptly while on these medications, levels may rise to toxic ranges,
necessitating careful monitoring and dose adjustment.
3. A patient taking Phenelzine (an MAOI) consumes a large amount of aged cheese and wine.
What is the most likely pathological outcome of this interaction?
A. Hypotensive crisis due to volume depletion
B. Serotonin syndrome due to excessive 5-HT
C. Hypertensive crisis due to tyramine accumulation
D. Neuroleptic malignant syndrome
Answer: C
, Rationale: Tyramine is an amino acid normally metabolized by Monoamine Oxidase (MAO)
in the gut. When MAOIs inhibit this process, tyramine enters the systemic circulation and
triggers a massive release of stored norepinephrine from sympathetic nerve terminals.
This results in severe vasoconstriction and a dangerous rise in blood pressure, known as a
hypertensive crisis.
4. The ‘therapeutic window’ for Lithium is narrow. Which of the following serum ranges is
generally considered therapeutic for acute mania?
A. 0.2 to 0.5 mEq/L
B. 2.5 to 3.5 mEq/L
C. 1.5 to 2.0 mEq/L
D. 0.8 to 1.2 mEq/L
Answer: D
Rationale: For the treatment of acute manic episodes, a lithium level of 0.8 to 1.2 mEq/L is
the standard target. Maintenance levels are typically lower, ranging from 0.6 to 1.0 mEq/L
to reduce long-term side effects. Monitoring is critical because toxicity can occur at levels
as low as 1.5 mEq/L, leading to neurological and renal complications.
5. A patient is prescribed Fluoxetine for depression. How long is the washout period required
before starting an MAOI to avoid serotonin syndrome?
A. 5 weeks
B. 1 week
