NCLEX-RN Neurological System
Pharmacology Practice Questions &
Rationales
20 NGN-Style MCQs | ATI Nursing Exam
Prep
Question 1
Clinical Scenario
A 24-year-old woman with newly diagnosed generalized tonic-
clonic seizures is prescribed phenytoin. She has no significant
medical history and takes an oral contraceptive daily. During
discharge teaching, the nurse reviews medication
administration and safety precautions.
Question Stem
Which statement by the client indicates the need for further
teaching?
A. "I should avoid stopping this medication suddenly without
talking to my healthcare provider."
,B. "I will schedule regular dental visits and practice good oral
hygiene."
C. "My birth control pills may not work as well while I am taking
this medication."
D. "If I miss several doses, I can double the next dose to catch
up."
Correct Answer
Correct Answer: D. "If I miss several doses, I can double the
next dose to catch up."
Detailed Rationale
Phenytoin is an antiseizure medication that stabilizes neuronal
membranes by blocking voltage-gated sodium channels,
thereby reducing abnormal electrical activity in the brain. The
medication has nonlinear (zero-order) pharmacokinetics,
meaning small dosage changes can significantly increase serum
concentrations and toxicity risk. Patients should never double
doses after missed doses because this may result in toxic serum
levels, leading to adverse effects such as nystagmus, ataxia,
slurred speech, confusion, or severe CNS depression. Instead,
they should contact their healthcare provider for guidance if
multiple doses are missed.
Option A is correct patient teaching because abrupt
discontinuation can precipitate rebound seizures or status
,epilepticus. Option B is appropriate because phenytoin
commonly causes gingival hyperplasia, making meticulous oral
hygiene and routine dental care essential. Option C is also
correct because phenytoin induces hepatic enzymes that
accelerate metabolism of estrogen-containing contraceptives,
reducing contraceptive effectiveness and increasing pregnancy
risk. Nurses should recommend an additional nonhormonal
contraceptive method. Therapeutic serum levels (10–20
mcg/mL) should be monitored, and patients should avoid
alcohol, which may alter drug levels.
Learning Objectives
After completing this question, the learner should be able to:
• Explain safe administration of phenytoin.
• Recognize important patient education regarding missed
doses.
• Identify common adverse effects requiring preventive
interventions.
• Discuss clinically significant drug interactions with
phenytoin.
Medication Safety Focus
Medication administration
, Question 2
Clinical Scenario
A 72-year-old man with Parkinson disease has been taking
carbidopa/levodopa for six months. During a clinic visit, he
reports improved mobility but states that the medication
"wears off" before the next scheduled dose. His blood pressure
is 108/64 mm Hg while sitting and 88/56 mm Hg when standing.
Question Stem
Which nursing intervention is the highest priority?
A. Encourage the client to increase dietary protein with each
medication dose.
B. Teach the client to rise slowly from sitting or lying positions.
C. Advise the client to stop taking the medication until
evaluated.
D. Recommend taking the medication only at bedtime.
Correct Answer
Correct Answer: B. Teach the client to rise slowly from sitting
or lying positions.
Detailed Rationale
Carbidopa/levodopa remains the most effective therapy for
improving bradykinesia and rigidity in Parkinson disease.
Pharmacology Practice Questions &
Rationales
20 NGN-Style MCQs | ATI Nursing Exam
Prep
Question 1
Clinical Scenario
A 24-year-old woman with newly diagnosed generalized tonic-
clonic seizures is prescribed phenytoin. She has no significant
medical history and takes an oral contraceptive daily. During
discharge teaching, the nurse reviews medication
administration and safety precautions.
Question Stem
Which statement by the client indicates the need for further
teaching?
A. "I should avoid stopping this medication suddenly without
talking to my healthcare provider."
,B. "I will schedule regular dental visits and practice good oral
hygiene."
C. "My birth control pills may not work as well while I am taking
this medication."
D. "If I miss several doses, I can double the next dose to catch
up."
Correct Answer
Correct Answer: D. "If I miss several doses, I can double the
next dose to catch up."
Detailed Rationale
Phenytoin is an antiseizure medication that stabilizes neuronal
membranes by blocking voltage-gated sodium channels,
thereby reducing abnormal electrical activity in the brain. The
medication has nonlinear (zero-order) pharmacokinetics,
meaning small dosage changes can significantly increase serum
concentrations and toxicity risk. Patients should never double
doses after missed doses because this may result in toxic serum
levels, leading to adverse effects such as nystagmus, ataxia,
slurred speech, confusion, or severe CNS depression. Instead,
they should contact their healthcare provider for guidance if
multiple doses are missed.
Option A is correct patient teaching because abrupt
discontinuation can precipitate rebound seizures or status
,epilepticus. Option B is appropriate because phenytoin
commonly causes gingival hyperplasia, making meticulous oral
hygiene and routine dental care essential. Option C is also
correct because phenytoin induces hepatic enzymes that
accelerate metabolism of estrogen-containing contraceptives,
reducing contraceptive effectiveness and increasing pregnancy
risk. Nurses should recommend an additional nonhormonal
contraceptive method. Therapeutic serum levels (10–20
mcg/mL) should be monitored, and patients should avoid
alcohol, which may alter drug levels.
Learning Objectives
After completing this question, the learner should be able to:
• Explain safe administration of phenytoin.
• Recognize important patient education regarding missed
doses.
• Identify common adverse effects requiring preventive
interventions.
• Discuss clinically significant drug interactions with
phenytoin.
Medication Safety Focus
Medication administration
, Question 2
Clinical Scenario
A 72-year-old man with Parkinson disease has been taking
carbidopa/levodopa for six months. During a clinic visit, he
reports improved mobility but states that the medication
"wears off" before the next scheduled dose. His blood pressure
is 108/64 mm Hg while sitting and 88/56 mm Hg when standing.
Question Stem
Which nursing intervention is the highest priority?
A. Encourage the client to increase dietary protein with each
medication dose.
B. Teach the client to rise slowly from sitting or lying positions.
C. Advise the client to stop taking the medication until
evaluated.
D. Recommend taking the medication only at bedtime.
Correct Answer
Correct Answer: B. Teach the client to rise slowly from sitting
or lying positions.
Detailed Rationale
Carbidopa/levodopa remains the most effective therapy for
improving bradykinesia and rigidity in Parkinson disease.
