NCLEX-RN Pharmacology Neurological
System Practice Questions
20 Original NGN-Style MCQs with
Detailed Rationales, Medication Safety,
Clinical Judgment & Nursing Exam
Review
Question 1
Clinical Scenario
A 72-year-old client with Parkinson disease is prescribed
carbidopa/levodopa. The nurse is reviewing the medication
history and learns that the client frequently takes an over-the-
counter iron supplement with breakfast. The client reports that
the medication "doesn't seem to work as well" in the morning
and has increasing difficulty initiating movement.
Question Stem
Which instruction should the nurse provide to improve the
therapeutic response to carbidopa/levodopa?
,A. Take the medication with a high-protein meal to improve
absorption.
B. Take the medication at the same time as the iron supplement
to prevent stomach irritation.
C. Separate the medication from iron-containing supplements
and discuss persistent symptoms with the provider.
D. Stop taking the medication whenever involuntary
movements occur.
Correct Answer
Correct Answer: C. Separate the medication from iron-
containing supplements and discuss persistent symptoms with
the provider.
Detailed Rationale
Carbidopa/levodopa is converted to dopamine in the brain,
improving motor symptoms associated with Parkinson disease.
Iron-containing supplements can reduce the absorption and
bioavailability of levodopa, potentially decreasing its
therapeutic effect. The nurse should instruct the client to
separate carbidopa/levodopa from iron supplements according
to prescribing guidance and to notify the provider if motor
symptoms remain poorly controlled.
Option A is incorrect because high-protein meals may interfere
with levodopa absorption and competition with amino acids
can reduce its transport into the brain; however, dietary protein
,should not be eliminated without individualized guidance.
Option B is incorrect because taking iron and levodopa together
may worsen, rather than improve, the medication's
effectiveness. Option D is unsafe because abrupt
discontinuation of antiparkinsonian therapy can result in severe
worsening of symptoms and potentially serious complications.
The nurse should also monitor for orthostatic hypotension,
dyskinesias, hallucinations, and involuntary movements.
Patients should rise slowly and avoid abruptly discontinuing
therapy.
Learning Objective
After completing this question, the learner should be able to:
• Identify an interaction that can decrease levodopa
effectiveness.
• Provide safe medication-administration teaching for
carbidopa/levodopa.
• Recognize the importance of monitoring therapeutic
response and adverse effects.
Medication Safety Focus
Drug interaction
Question 2
, Clinical Scenario
A 34-year-old client with generalized tonic-clonic seizures is
prescribed phenytoin. During a follow-up visit, the nurse notes
that the client has a serum phenytoin concentration of 28
mcg/mL (therapeutic range commonly approximately 10–20
mcg/mL). The client reports unsteady gait, blurred vision, and
nausea.
Question Stem
Which action should the nurse take first?
A. Administer the next scheduled dose with food.
B. Hold the medication and notify the provider of suspected
phenytoin toxicity.
C. Encourage the client to increase fluid intake and continue
therapy.
D. Reassure the client that these findings indicate effective
seizure control.
Correct Answer
Correct Answer: B. Hold the medication and notify the
provider of suspected phenytoin toxicity.
Detailed Rationale
The client has a supratherapeutic phenytoin concentration
accompanied by classic manifestations of toxicity, including
nystagmus or visual disturbances, ataxia, and gastrointestinal
System Practice Questions
20 Original NGN-Style MCQs with
Detailed Rationales, Medication Safety,
Clinical Judgment & Nursing Exam
Review
Question 1
Clinical Scenario
A 72-year-old client with Parkinson disease is prescribed
carbidopa/levodopa. The nurse is reviewing the medication
history and learns that the client frequently takes an over-the-
counter iron supplement with breakfast. The client reports that
the medication "doesn't seem to work as well" in the morning
and has increasing difficulty initiating movement.
Question Stem
Which instruction should the nurse provide to improve the
therapeutic response to carbidopa/levodopa?
,A. Take the medication with a high-protein meal to improve
absorption.
B. Take the medication at the same time as the iron supplement
to prevent stomach irritation.
C. Separate the medication from iron-containing supplements
and discuss persistent symptoms with the provider.
D. Stop taking the medication whenever involuntary
movements occur.
Correct Answer
Correct Answer: C. Separate the medication from iron-
containing supplements and discuss persistent symptoms with
the provider.
Detailed Rationale
Carbidopa/levodopa is converted to dopamine in the brain,
improving motor symptoms associated with Parkinson disease.
Iron-containing supplements can reduce the absorption and
bioavailability of levodopa, potentially decreasing its
therapeutic effect. The nurse should instruct the client to
separate carbidopa/levodopa from iron supplements according
to prescribing guidance and to notify the provider if motor
symptoms remain poorly controlled.
Option A is incorrect because high-protein meals may interfere
with levodopa absorption and competition with amino acids
can reduce its transport into the brain; however, dietary protein
,should not be eliminated without individualized guidance.
Option B is incorrect because taking iron and levodopa together
may worsen, rather than improve, the medication's
effectiveness. Option D is unsafe because abrupt
discontinuation of antiparkinsonian therapy can result in severe
worsening of symptoms and potentially serious complications.
The nurse should also monitor for orthostatic hypotension,
dyskinesias, hallucinations, and involuntary movements.
Patients should rise slowly and avoid abruptly discontinuing
therapy.
Learning Objective
After completing this question, the learner should be able to:
• Identify an interaction that can decrease levodopa
effectiveness.
• Provide safe medication-administration teaching for
carbidopa/levodopa.
• Recognize the importance of monitoring therapeutic
response and adverse effects.
Medication Safety Focus
Drug interaction
Question 2
, Clinical Scenario
A 34-year-old client with generalized tonic-clonic seizures is
prescribed phenytoin. During a follow-up visit, the nurse notes
that the client has a serum phenytoin concentration of 28
mcg/mL (therapeutic range commonly approximately 10–20
mcg/mL). The client reports unsteady gait, blurred vision, and
nausea.
Question Stem
Which action should the nurse take first?
A. Administer the next scheduled dose with food.
B. Hold the medication and notify the provider of suspected
phenytoin toxicity.
C. Encourage the client to increase fluid intake and continue
therapy.
D. Reassure the client that these findings indicate effective
seizure control.
Correct Answer
Correct Answer: B. Hold the medication and notify the
provider of suspected phenytoin toxicity.
Detailed Rationale
The client has a supratherapeutic phenytoin concentration
accompanied by classic manifestations of toxicity, including
nystagmus or visual disturbances, ataxia, and gastrointestinal
