NR 566 Week 7 Exam – CNS Disorders:
Comprehensive Exam Questions with Correct
Answers (VerifiedAnswers) Plus Rationales
2026 Q&A Instant Download PDF
Question 1
A patient with Parkinson disease is prescribed
carbidopa/levodopa. What is the primary purpose of adding
carbidopa?
A. To stimulate dopamine receptors directly in the brain
B. To increase dopamine breakdown in the CNS
C. To inhibit peripheral conversion of levodopa to dopamine
D. To prevent levodopa from crossing the blood-brain barrier
Rationale: Carbidopa inhibits peripheral dopa decarboxylase,
reducing the conversion of levodopa to dopamine outside the
brain. This allows a greater proportion of levodopa to reach the
CNS, where it can be converted to dopamine. Carbidopa also
reduces peripheral adverse effects such as nausea, vomiting,
and cardiovascular effects associated with peripheral dopamine.
Question 2
Which adverse effect should the nurse anticipate in a patient
beginning carbidopa/levodopa therapy?
,A. Severe constipation only
B. Nausea and orthostatic hypotension
C. Profound hypoglycemia
D. Severe neutropenia
Rationale: Levodopa can cause nausea, vomiting, orthostatic
hypotension, dyskinesias, hallucinations, and other
dopaminergic effects. Orthostatic hypotension is particularly
important because it increases the risk of dizziness and falls.
Patients should be taught to rise slowly from sitting or lying
positions.
Question 3
A patient taking levodopa reports that the medication does not
seem to work as well after eating a high-protein meal. What is
the best explanation?
A. Protein permanently destroys levodopa
B. Protein prevents carbidopa from working
C. Protein increases renal elimination of dopamine
D. Large amounts of dietary amino acids can interfere with
levodopa absorption and transport
Rationale: Levodopa and dietary amino acids use related
transport mechanisms in the gastrointestinal tract and across
the blood-brain barrier. A high-protein diet may therefore
reduce levodopa absorption or CNS availability in some patients.
,Consistency in the timing and composition of meals can help
minimize fluctuations in therapeutic response.
Question 4
Which medication is a dopamine agonist commonly used to
treat Parkinson disease?
A. Entacapone
B. Selegiline
C. Pramipexole
D. Benztropine
Rationale: Pramipexole directly stimulates dopamine receptors
and can improve motor symptoms of Parkinson disease. Other
dopamine agonists include ropinirole and rotigotine. These
agents can cause hallucinations, somnolence, orthostatic
hypotension, and impulse-control problems.
Question 5
A patient taking pramipexole reports compulsive gambling that
was not present before treatment. What should the clinician
recognize?
A. This is an expected sign of therapeutic effectiveness
B. This indicates serotonin syndrome
C. This is evidence of worsening dementia
D. This may represent a dopamine agonist–associated
impulse-control disorder
, Rationale: Dopamine agonists can produce impulse-control
disorders, including compulsive gambling, shopping, eating, or
sexual behaviors. These effects may be distressing and may not
be recognized by the patient initially. The prescriber should
assess the severity and consider dose reduction or an
alternative treatment when appropriate.
Question 6
What is the primary mechanism of entacapone in Parkinson
disease?
A. Direct stimulation of dopamine receptors
B. Inhibition of acetylcholinesterase
C. Inhibition of peripheral catechol-O-methyltransferase
(COMT)
D. Blockade of muscarinic receptors
Rationale: Entacapone inhibits COMT, an enzyme involved in
levodopa metabolism. By reducing peripheral levodopa
breakdown, entacapone increases the amount of levodopa
available to reach the brain and can prolong its therapeutic
effect. It is generally used with levodopa/carbidopa rather than
as monotherapy.
Question 7
Which adverse effect is particularly important to monitor in a
patient receiving entacapone?
Comprehensive Exam Questions with Correct
Answers (VerifiedAnswers) Plus Rationales
2026 Q&A Instant Download PDF
Question 1
A patient with Parkinson disease is prescribed
carbidopa/levodopa. What is the primary purpose of adding
carbidopa?
A. To stimulate dopamine receptors directly in the brain
B. To increase dopamine breakdown in the CNS
C. To inhibit peripheral conversion of levodopa to dopamine
D. To prevent levodopa from crossing the blood-brain barrier
Rationale: Carbidopa inhibits peripheral dopa decarboxylase,
reducing the conversion of levodopa to dopamine outside the
brain. This allows a greater proportion of levodopa to reach the
CNS, where it can be converted to dopamine. Carbidopa also
reduces peripheral adverse effects such as nausea, vomiting,
and cardiovascular effects associated with peripheral dopamine.
Question 2
Which adverse effect should the nurse anticipate in a patient
beginning carbidopa/levodopa therapy?
,A. Severe constipation only
B. Nausea and orthostatic hypotension
C. Profound hypoglycemia
D. Severe neutropenia
Rationale: Levodopa can cause nausea, vomiting, orthostatic
hypotension, dyskinesias, hallucinations, and other
dopaminergic effects. Orthostatic hypotension is particularly
important because it increases the risk of dizziness and falls.
Patients should be taught to rise slowly from sitting or lying
positions.
Question 3
A patient taking levodopa reports that the medication does not
seem to work as well after eating a high-protein meal. What is
the best explanation?
A. Protein permanently destroys levodopa
B. Protein prevents carbidopa from working
C. Protein increases renal elimination of dopamine
D. Large amounts of dietary amino acids can interfere with
levodopa absorption and transport
Rationale: Levodopa and dietary amino acids use related
transport mechanisms in the gastrointestinal tract and across
the blood-brain barrier. A high-protein diet may therefore
reduce levodopa absorption or CNS availability in some patients.
,Consistency in the timing and composition of meals can help
minimize fluctuations in therapeutic response.
Question 4
Which medication is a dopamine agonist commonly used to
treat Parkinson disease?
A. Entacapone
B. Selegiline
C. Pramipexole
D. Benztropine
Rationale: Pramipexole directly stimulates dopamine receptors
and can improve motor symptoms of Parkinson disease. Other
dopamine agonists include ropinirole and rotigotine. These
agents can cause hallucinations, somnolence, orthostatic
hypotension, and impulse-control problems.
Question 5
A patient taking pramipexole reports compulsive gambling that
was not present before treatment. What should the clinician
recognize?
A. This is an expected sign of therapeutic effectiveness
B. This indicates serotonin syndrome
C. This is evidence of worsening dementia
D. This may represent a dopamine agonist–associated
impulse-control disorder
, Rationale: Dopamine agonists can produce impulse-control
disorders, including compulsive gambling, shopping, eating, or
sexual behaviors. These effects may be distressing and may not
be recognized by the patient initially. The prescriber should
assess the severity and consider dose reduction or an
alternative treatment when appropriate.
Question 6
What is the primary mechanism of entacapone in Parkinson
disease?
A. Direct stimulation of dopamine receptors
B. Inhibition of acetylcholinesterase
C. Inhibition of peripheral catechol-O-methyltransferase
(COMT)
D. Blockade of muscarinic receptors
Rationale: Entacapone inhibits COMT, an enzyme involved in
levodopa metabolism. By reducing peripheral levodopa
breakdown, entacapone increases the amount of levodopa
available to reach the brain and can prolong its therapeutic
effect. It is generally used with levodopa/carbidopa rather than
as monotherapy.
Question 7
Which adverse effect is particularly important to monitor in a
patient receiving entacapone?
