NR 546 Week 8 Neurotransmitter Table
Completed Guide - Advanced
Psychopharmacology Solutions
Question 1
A 24-year-old male diagnosed with schizophrenia is initiated on haloperidol.
Within 48 hours, he develops severe, painful spasms of his neck muscles,
causing his head to twist involuntarily to one side. Which of the following
neurotransmitter mechanisms is directly responsible for this acute
extrapyramidal symptom (EPS)?
,A. Direct activation of muscarinic acetylcholine receptors in the striatum
B. Profound blockade of dopamine D₂ receptors in the nigrostriatal pathway
C. Downregulation of serotonin 5-HT₂A receptors in the prefrontal cortex
D. Hyper-activation of GABAergic interneurons within the nucleus accumbens
Verified Answer: B. Profound blockade of dopamine D₂ receptors in the
nigrostriatal pathway
Explanation: Acute dystonic reactions are extrapyramidal symptoms (EPS)
caused by a high degree of dopamine D₂ receptor antagonism within the
nigrostriatal pathway. When D₂ receptors are intensely blocked by First-
Generation Antipsychotics (FGAs) like haloperidol, the normal inhibitory
effect of dopamine on cholinergic neurons is lost. This leads to a relative
excess of acetylcholine output, triggering acute, severe muscular spasms.
Treatment consists of anticholinergic medications like benztropine or
diphenhydramine.
Question 2
A PMHNP is considering a switch from a Second-Generation Antipsychotic
(SGA) with high metabolic risk to one with a lower metabolic profile. The
patient has a history of severe weight gain and hyperlipidemia. Which receptor
profile combination is most characteristic of an atypical antipsychotic that
carries the lowest risk for weight gain and metabolic syndrome?
A. High affinity for Histamine H₁ and Serotonin 5-HT₂C receptors
B. Minimal affinity for Histamine H₁ and Serotonin 5-HT₂C receptors, with 5-
HT₁A partial agonism
C. Strong antagonism of Muscarinic M₁ and Alpha-1 adrenergic receptors
D. Selective and potent inhibition of Dopamine D₄ receptors
Verified Answer: B. Minimal affinity for Histamine H₁ and Serotonin 5-HT₂C
receptors, with 5-HT₁A partial agonism
Explanation: Drug-induced weight gain and metabolic dysregulation
associated with atypical antipsychotics are primarily mediated by intense
antagonism at Histamine H₁ and Serotonin 5-HT₂C receptors (as seen heavily
with clozapine and olanzapine). Agents that avoid or have very low affinity for
these two specific targets—such as aripiprazole, ziprasidone, or lurasidone—
,demonstrate significantly lower metabolic risk. 5-HT₁A partial agonism
further assists by modulating downstream dopamine and serotonin balance
favorably.
Question 3
A 43-year-old female stabilized on a standard dose of duloxetine for Major
Depressive Disorder presents with persistent complaints of severe nocturnal
sweating and an increased heart rate. Which neurochemical action of duloxetine
is primarily responsible for these physical side effects?
A. Chronic up-regulation of postsynaptic 5-HT₁A receptors
B. Potentiation of norepinephrine within the sympathetic nervous system
C. Antagonism of central histamine H₁ receptors
D. Alpha-1 adrenergic receptor blockade in peripheral blood vessels
Verified Answer: B. Potentiation of norepinephrine within the sympathetic
nervous system
Explanation: Duloxetine is a Serotonin-Norepinephrine Reuptake Inhibitor
(SNRI). By inhibiting the norepinephrine transporter (NET), it increases
synaptic concentrations of norepinephrine. Centrally and peripherally,
elevated noradrenergic tone stimulates alpha-1 and beta-1 adrenergic
receptors within the sympathetic nervous system. This manifests clinically as
side effects such as diaphoresis (sweating), tachycardia (increased heart rate),
elevated blood pressure, and dry mouth.
Question 4
A patient presents to the emergency department with altered mental status,
neuromuscular rigidity, hyperthermia, and autonomic instability. The family
notes the patient recently started taking an antidepressant alongside an over-the-
counter cough suppressant containing dextromethorphan. What is the
fundamental pathophysiology underlying this condition?
A. Hypo-activation of the dopamine D₂ receptor pathway in the hypothalamus
, B. Toxic accumulation of intrasynaptic serotonin (5-HT) causing hyper-
stimulation of 5-HT₁A and 5-HT₂A receptors
C. Abrupt withdrawal of gamma-aminobutyric acid (GABA) mediated
hyperpolarization
D. Excitotoxic surges of glutamate secondary to NMDA receptor over-
stimulation
Verified Answer: B. Toxic accumulation of intrasynaptic serotonin (5-HT)
causing hyper-stimulation of 5-HT₁A and 5-HT₂A receptors
Explanation: This patient is presenting with Serotonin Syndrome, a
potentially life-threatening condition caused by therapeutic drug
management, intentional overdose, or drug-drug interactions (such as
combining an SSRI/SNRI with dextromethorphan, which has weak serotonin
reuptake inhibiting properties). This interaction causes a toxic accumulation
of serotonin in the synaptic cleft, leading to overstimulation of postsynaptic
serotonin receptors, particularly 5-HT₁A and 5-HT₂A, resulting in
hyperreflexia, clonus, autonomic instability, and hyperthermia.
Question 5
When managing a patient on clozapine, the PMHNP tracks the Absolute
Neutrophil Count (ANC) regularly. If a patient develops severe neutropenia
(ANC below 500/µL), what immediate physiological danger demands the
absolute cessation of the drug and emergency medical intervention?
A. A sudden, catastrophic drop in systemic blood pressure due to alpha-
adrenergic collapse
B. Overwhelming systemic bacterial or fungal infection due to loss of innate
immune defenses
C. Acute bone marrow aplasia leading to immediate and fatal internal
hemorrhaging
D. Malignant hyperthermia secondary to structural changes in white blood cells
Verified Answer: B. Overwhelming systemic bacterial or fungal infection due
to loss of innate immune defenses
Explanation: Clozapine carries a black box warning for severe neutropenia
(formerly referred to heavily as agranulocytosis). Neutrophils are the body’s
Completed Guide - Advanced
Psychopharmacology Solutions
Question 1
A 24-year-old male diagnosed with schizophrenia is initiated on haloperidol.
Within 48 hours, he develops severe, painful spasms of his neck muscles,
causing his head to twist involuntarily to one side. Which of the following
neurotransmitter mechanisms is directly responsible for this acute
extrapyramidal symptom (EPS)?
,A. Direct activation of muscarinic acetylcholine receptors in the striatum
B. Profound blockade of dopamine D₂ receptors in the nigrostriatal pathway
C. Downregulation of serotonin 5-HT₂A receptors in the prefrontal cortex
D. Hyper-activation of GABAergic interneurons within the nucleus accumbens
Verified Answer: B. Profound blockade of dopamine D₂ receptors in the
nigrostriatal pathway
Explanation: Acute dystonic reactions are extrapyramidal symptoms (EPS)
caused by a high degree of dopamine D₂ receptor antagonism within the
nigrostriatal pathway. When D₂ receptors are intensely blocked by First-
Generation Antipsychotics (FGAs) like haloperidol, the normal inhibitory
effect of dopamine on cholinergic neurons is lost. This leads to a relative
excess of acetylcholine output, triggering acute, severe muscular spasms.
Treatment consists of anticholinergic medications like benztropine or
diphenhydramine.
Question 2
A PMHNP is considering a switch from a Second-Generation Antipsychotic
(SGA) with high metabolic risk to one with a lower metabolic profile. The
patient has a history of severe weight gain and hyperlipidemia. Which receptor
profile combination is most characteristic of an atypical antipsychotic that
carries the lowest risk for weight gain and metabolic syndrome?
A. High affinity for Histamine H₁ and Serotonin 5-HT₂C receptors
B. Minimal affinity for Histamine H₁ and Serotonin 5-HT₂C receptors, with 5-
HT₁A partial agonism
C. Strong antagonism of Muscarinic M₁ and Alpha-1 adrenergic receptors
D. Selective and potent inhibition of Dopamine D₄ receptors
Verified Answer: B. Minimal affinity for Histamine H₁ and Serotonin 5-HT₂C
receptors, with 5-HT₁A partial agonism
Explanation: Drug-induced weight gain and metabolic dysregulation
associated with atypical antipsychotics are primarily mediated by intense
antagonism at Histamine H₁ and Serotonin 5-HT₂C receptors (as seen heavily
with clozapine and olanzapine). Agents that avoid or have very low affinity for
these two specific targets—such as aripiprazole, ziprasidone, or lurasidone—
,demonstrate significantly lower metabolic risk. 5-HT₁A partial agonism
further assists by modulating downstream dopamine and serotonin balance
favorably.
Question 3
A 43-year-old female stabilized on a standard dose of duloxetine for Major
Depressive Disorder presents with persistent complaints of severe nocturnal
sweating and an increased heart rate. Which neurochemical action of duloxetine
is primarily responsible for these physical side effects?
A. Chronic up-regulation of postsynaptic 5-HT₁A receptors
B. Potentiation of norepinephrine within the sympathetic nervous system
C. Antagonism of central histamine H₁ receptors
D. Alpha-1 adrenergic receptor blockade in peripheral blood vessels
Verified Answer: B. Potentiation of norepinephrine within the sympathetic
nervous system
Explanation: Duloxetine is a Serotonin-Norepinephrine Reuptake Inhibitor
(SNRI). By inhibiting the norepinephrine transporter (NET), it increases
synaptic concentrations of norepinephrine. Centrally and peripherally,
elevated noradrenergic tone stimulates alpha-1 and beta-1 adrenergic
receptors within the sympathetic nervous system. This manifests clinically as
side effects such as diaphoresis (sweating), tachycardia (increased heart rate),
elevated blood pressure, and dry mouth.
Question 4
A patient presents to the emergency department with altered mental status,
neuromuscular rigidity, hyperthermia, and autonomic instability. The family
notes the patient recently started taking an antidepressant alongside an over-the-
counter cough suppressant containing dextromethorphan. What is the
fundamental pathophysiology underlying this condition?
A. Hypo-activation of the dopamine D₂ receptor pathway in the hypothalamus
, B. Toxic accumulation of intrasynaptic serotonin (5-HT) causing hyper-
stimulation of 5-HT₁A and 5-HT₂A receptors
C. Abrupt withdrawal of gamma-aminobutyric acid (GABA) mediated
hyperpolarization
D. Excitotoxic surges of glutamate secondary to NMDA receptor over-
stimulation
Verified Answer: B. Toxic accumulation of intrasynaptic serotonin (5-HT)
causing hyper-stimulation of 5-HT₁A and 5-HT₂A receptors
Explanation: This patient is presenting with Serotonin Syndrome, a
potentially life-threatening condition caused by therapeutic drug
management, intentional overdose, or drug-drug interactions (such as
combining an SSRI/SNRI with dextromethorphan, which has weak serotonin
reuptake inhibiting properties). This interaction causes a toxic accumulation
of serotonin in the synaptic cleft, leading to overstimulation of postsynaptic
serotonin receptors, particularly 5-HT₁A and 5-HT₂A, resulting in
hyperreflexia, clonus, autonomic instability, and hyperthermia.
Question 5
When managing a patient on clozapine, the PMHNP tracks the Absolute
Neutrophil Count (ANC) regularly. If a patient develops severe neutropenia
(ANC below 500/µL), what immediate physiological danger demands the
absolute cessation of the drug and emergency medical intervention?
A. A sudden, catastrophic drop in systemic blood pressure due to alpha-
adrenergic collapse
B. Overwhelming systemic bacterial or fungal infection due to loss of innate
immune defenses
C. Acute bone marrow aplasia leading to immediate and fatal internal
hemorrhaging
D. Malignant hyperthermia secondary to structural changes in white blood cells
Verified Answer: B. Overwhelming systemic bacterial or fungal infection due
to loss of innate immune defenses
Explanation: Clozapine carries a black box warning for severe neutropenia
(formerly referred to heavily as agranulocytosis). Neutrophils are the body’s
