NR546 | NR546 Advanced Pharmacology
Psychopharmacology for the PMHNP Week 1 Exam
1 | Questions with Correct Answers and Expert
Explanation for Each Question | Chamberlain
1. Which neurotransmitter is considered the primary inhibitory neurotransmitter in
the mammalian central nervous system?
A. Glutamate
B. Dopamine
C. GABA
D. Norepinephrine
Correct Answer: C
Expert Explanation: Gamma-aminobutyric acid (GABA) is the principal inhibitory
neurotransmitter in the brain, working to reduce neuronal excitability. It
counterbalances the effects of excitatory neurotransmitters like glutamate to
maintain homeostasis. In clinical practice, medications that enhance GABAergic
activity are often used to treat anxiety and insomnia.
2. When an agonist binds to a G-protein-coupled receptor, which of the following best
describes the outcome?
A. It stabilizes the receptor in an inactive state.
,B. It blocks the binding of the endogenous neurotransmitter without activating the
receptor.
C. It stimulates the receptor to produce a maximum biological response.
D. It causes the receptor to perform the opposite of its intended function.
Correct Answer: C
Expert Explanation: An agonist mimics the action of an endogenous
neurotransmitter by binding to the receptor and initiating a full biological response.
This interaction typically shifts the receptor into an active conformation, triggering
downstream signaling cascades. Understanding the agonist spectrum is crucial for
predicting the efficacy and potency of psychotropic medications.
3. The cytochrome P450 (CYP450) enzyme system is primarily responsible for which
phase of drug metabolism?
A. Phase IV
B. Phase II
C. Phase III
D. Phase I
Correct Answer: D
,Expert Explanation: Phase I metabolism involves oxidative, reductive, and
hydrolytic reactions, with the CYP450 enzyme family being the most significant
players. These reactions often introduce or expose a functional group on the drug
molecule to prepare it for further processing. Phase II metabolism usually follows,
involving conjugation to make the drug more water-soluble for excretion.
4. Which dopamine pathway is associated with the development of extrapyramidal
symptoms (EPS) when D2 receptors are blocked?
A. Mesolimbic pathway
B. Nigrostriatal pathway
C. Mesocortical pathway
D. Tuberoinfundibular pathway
Correct Answer: B
Expert Explanation: The nigrostriatal pathway projects from the substantia nigra
to the striatum and is responsible for motor control. Chronic blockade of D2
receptors in this pathway by first-generation antipsychotics leads to movement
disorders like akathisia and parkinsonism. Clinicians must monitor this pathway
closely when managing patients on high-potency neuroleptics.
5. Which of the following describes the ‘constitutive activity’ of a receptor?
A. The baseline level of activity occurring even in the absence of a ligand.
, B. The activity level only when an agonist is present.
C. The state of the receptor when it is being degraded by enzymes.
D. The rate at which the receptor is synthesized by the cell.
Correct Answer: A
Expert Explanation: Constitutive activity refers to the inherent signaling of a
receptor when no ligand is bound to it. Some receptors exhibit a ‘leak’ of signal that
maintains a certain physiological tone. Inverse agonists are unique because they
reduce this constitutive activity below the baseline level.
6. An ‘inverse agonist’ does which of the following at a receptor site?
A. Produces the same effect as an agonist but with less intensity.
B. Blocks the effects of an agonist but has no activity of its own.
C. Reduces the constitutive activity of the receptor.
D. Permanently binds and destroys the receptor.
Correct Answer: C
Expert Explanation: Inverse agonists do more than just block a receptor; they
actually decrease the baseline or constitutive activity of the receptor. This is
different from a simple antagonist, which only prevents other ligands from binding.
Psychopharmacology for the PMHNP Week 1 Exam
1 | Questions with Correct Answers and Expert
Explanation for Each Question | Chamberlain
1. Which neurotransmitter is considered the primary inhibitory neurotransmitter in
the mammalian central nervous system?
A. Glutamate
B. Dopamine
C. GABA
D. Norepinephrine
Correct Answer: C
Expert Explanation: Gamma-aminobutyric acid (GABA) is the principal inhibitory
neurotransmitter in the brain, working to reduce neuronal excitability. It
counterbalances the effects of excitatory neurotransmitters like glutamate to
maintain homeostasis. In clinical practice, medications that enhance GABAergic
activity are often used to treat anxiety and insomnia.
2. When an agonist binds to a G-protein-coupled receptor, which of the following best
describes the outcome?
A. It stabilizes the receptor in an inactive state.
,B. It blocks the binding of the endogenous neurotransmitter without activating the
receptor.
C. It stimulates the receptor to produce a maximum biological response.
D. It causes the receptor to perform the opposite of its intended function.
Correct Answer: C
Expert Explanation: An agonist mimics the action of an endogenous
neurotransmitter by binding to the receptor and initiating a full biological response.
This interaction typically shifts the receptor into an active conformation, triggering
downstream signaling cascades. Understanding the agonist spectrum is crucial for
predicting the efficacy and potency of psychotropic medications.
3. The cytochrome P450 (CYP450) enzyme system is primarily responsible for which
phase of drug metabolism?
A. Phase IV
B. Phase II
C. Phase III
D. Phase I
Correct Answer: D
,Expert Explanation: Phase I metabolism involves oxidative, reductive, and
hydrolytic reactions, with the CYP450 enzyme family being the most significant
players. These reactions often introduce or expose a functional group on the drug
molecule to prepare it for further processing. Phase II metabolism usually follows,
involving conjugation to make the drug more water-soluble for excretion.
4. Which dopamine pathway is associated with the development of extrapyramidal
symptoms (EPS) when D2 receptors are blocked?
A. Mesolimbic pathway
B. Nigrostriatal pathway
C. Mesocortical pathway
D. Tuberoinfundibular pathway
Correct Answer: B
Expert Explanation: The nigrostriatal pathway projects from the substantia nigra
to the striatum and is responsible for motor control. Chronic blockade of D2
receptors in this pathway by first-generation antipsychotics leads to movement
disorders like akathisia and parkinsonism. Clinicians must monitor this pathway
closely when managing patients on high-potency neuroleptics.
5. Which of the following describes the ‘constitutive activity’ of a receptor?
A. The baseline level of activity occurring even in the absence of a ligand.
, B. The activity level only when an agonist is present.
C. The state of the receptor when it is being degraded by enzymes.
D. The rate at which the receptor is synthesized by the cell.
Correct Answer: A
Expert Explanation: Constitutive activity refers to the inherent signaling of a
receptor when no ligand is bound to it. Some receptors exhibit a ‘leak’ of signal that
maintains a certain physiological tone. Inverse agonists are unique because they
reduce this constitutive activity below the baseline level.
6. An ‘inverse agonist’ does which of the following at a receptor site?
A. Produces the same effect as an agonist but with less intensity.
B. Blocks the effects of an agonist but has no activity of its own.
C. Reduces the constitutive activity of the receptor.
D. Permanently binds and destroys the receptor.
Correct Answer: C
Expert Explanation: Inverse agonists do more than just block a receptor; they
actually decrease the baseline or constitutive activity of the receptor. This is
different from a simple antagonist, which only prevents other ligands from binding.
