NCLEX-RN Pharmacology Neurological System
Part 2 Practice Questions |
20 Original NGN-Style MCQs with Rationales |
Nursing Exam Prep
Question 1
Clinical Scenario
A 45-year-old male with a history of a seizure disorder presents
to the emergency department complaining of dizziness,
unsteady gait, and confusion. He reports taking his prescribed
phenytoin daily. On assessment, the nurse notes horizontal
nystagmus and slurred speech.
Question Stem
Which laboratory finding should the nurse anticipate reviewing
to confirm the cause of these symptoms?
A. Phenytoin level of 12 mcg/mL
B. Phenytoin level of 22 mcg/mL
C. Alanine aminotransferase (ALT) of 45 U/L
D. White blood cell (WBC) count of 8,000/mm³
,Correct Answer
Correct Answer: B. Phenytoin level of 22 mcg/mL
Detailed Rationale
The correct answer is B. The therapeutic serum level for
phenytoin is 10 to 20 mcg/mL. A level of 22 mcg/mL indicates
toxicity. Clinical manifestations of phenytoin toxicity include
nystagmus, ataxia, slurred speech, confusion, and lethargy.
Levels above 30 mcg/mL can lead to severe toxicity, including
coma and paradoxical seizures. Option A is incorrect because 12
mcg/mL is within the therapeutic range and would not typically
cause these toxic neurological symptoms. Option C is incorrect
because while phenytoin can cause hepatotoxicity, an ALT of 45
U/L is only mildly elevated (normal is typically up to 40-50 U/L)
and does not explain the acute neurological presentation.
Option D is incorrect because a WBC of 8,000/mm³ is within
normal limits; although phenytoin can rarely cause blood
dyscrasias, it is not the primary cause of this client's current
symptoms. The nurse must recognize these signs of toxicity,
hold the medication, and notify the provider immediately for a
dosage adjustment.
Learning Objective
• Identify clinical manifestations of phenytoin toxicity.
• Interpret therapeutic drug monitoring levels for
antiepileptic medications.
, • Prioritize nursing assessments for clients on narrow-
therapeutic-index drugs.
Medication Safety Focus
Monitoring
Question 2
Clinical Scenario
A 68-year-old female with Parkinson’s disease is being
discharged with a new prescription for levodopa/carbidopa. The
nurse is providing discharge education regarding medication
administration and expected effects.
Question Stem
Which statement by the client indicates understanding of the
patient teaching?
A. "I will take this medication with a high-protein meal to
prevent stomach upset."
B. "My urine may turn a dark color, which is an expected and
harmless finding."
C. "I should stop taking this medication immediately if my
tremors completely improve."
D. "I will take an over-the-counter vitamin B6 supplement to
enhance the medication's effects."
, Correct Answer
Correct Answer: B. "My urine may turn a dark color, which is an
expected and harmless finding."
Detailed Rationale
The correct answer is B. Levodopa/carbidopa can cause a
harmless brownish or dark discoloration of urine, sweat, and
saliva. Educating the client about this prevents unnecessary
anxiety. Option A is incorrect because high-protein meals
interfere with the absorption of levodopa in the small intestine,
reducing its efficacy; it should be taken 30–60 minutes before
meals or with a low-protein snack. Option C is incorrect because
abrupt discontinuation of antiparkinsonian medications can
lead to a life-threatening condition resembling neuroleptic
malignant syndrome (parkinsonian-hyperpyrexia syndrome).
Option D is incorrect because vitamin B6 (pyridoxine)
accelerates the peripheral breakdown of levodopa, decreasing
its effectiveness in the brain (though this is less of an issue
when combined with carbidopa, it is still generally discouraged
without provider approval).
Learning Objective
• Educate patients on expected, harmless adverse effects of
levodopa/carbidopa.
• Identify dietary interactions that decrease levodopa
efficacy.
Part 2 Practice Questions |
20 Original NGN-Style MCQs with Rationales |
Nursing Exam Prep
Question 1
Clinical Scenario
A 45-year-old male with a history of a seizure disorder presents
to the emergency department complaining of dizziness,
unsteady gait, and confusion. He reports taking his prescribed
phenytoin daily. On assessment, the nurse notes horizontal
nystagmus and slurred speech.
Question Stem
Which laboratory finding should the nurse anticipate reviewing
to confirm the cause of these symptoms?
A. Phenytoin level of 12 mcg/mL
B. Phenytoin level of 22 mcg/mL
C. Alanine aminotransferase (ALT) of 45 U/L
D. White blood cell (WBC) count of 8,000/mm³
,Correct Answer
Correct Answer: B. Phenytoin level of 22 mcg/mL
Detailed Rationale
The correct answer is B. The therapeutic serum level for
phenytoin is 10 to 20 mcg/mL. A level of 22 mcg/mL indicates
toxicity. Clinical manifestations of phenytoin toxicity include
nystagmus, ataxia, slurred speech, confusion, and lethargy.
Levels above 30 mcg/mL can lead to severe toxicity, including
coma and paradoxical seizures. Option A is incorrect because 12
mcg/mL is within the therapeutic range and would not typically
cause these toxic neurological symptoms. Option C is incorrect
because while phenytoin can cause hepatotoxicity, an ALT of 45
U/L is only mildly elevated (normal is typically up to 40-50 U/L)
and does not explain the acute neurological presentation.
Option D is incorrect because a WBC of 8,000/mm³ is within
normal limits; although phenytoin can rarely cause blood
dyscrasias, it is not the primary cause of this client's current
symptoms. The nurse must recognize these signs of toxicity,
hold the medication, and notify the provider immediately for a
dosage adjustment.
Learning Objective
• Identify clinical manifestations of phenytoin toxicity.
• Interpret therapeutic drug monitoring levels for
antiepileptic medications.
, • Prioritize nursing assessments for clients on narrow-
therapeutic-index drugs.
Medication Safety Focus
Monitoring
Question 2
Clinical Scenario
A 68-year-old female with Parkinson’s disease is being
discharged with a new prescription for levodopa/carbidopa. The
nurse is providing discharge education regarding medication
administration and expected effects.
Question Stem
Which statement by the client indicates understanding of the
patient teaching?
A. "I will take this medication with a high-protein meal to
prevent stomach upset."
B. "My urine may turn a dark color, which is an expected and
harmless finding."
C. "I should stop taking this medication immediately if my
tremors completely improve."
D. "I will take an over-the-counter vitamin B6 supplement to
enhance the medication's effects."
, Correct Answer
Correct Answer: B. "My urine may turn a dark color, which is an
expected and harmless finding."
Detailed Rationale
The correct answer is B. Levodopa/carbidopa can cause a
harmless brownish or dark discoloration of urine, sweat, and
saliva. Educating the client about this prevents unnecessary
anxiety. Option A is incorrect because high-protein meals
interfere with the absorption of levodopa in the small intestine,
reducing its efficacy; it should be taken 30–60 minutes before
meals or with a low-protein snack. Option C is incorrect because
abrupt discontinuation of antiparkinsonian medications can
lead to a life-threatening condition resembling neuroleptic
malignant syndrome (parkinsonian-hyperpyrexia syndrome).
Option D is incorrect because vitamin B6 (pyridoxine)
accelerates the peripheral breakdown of levodopa, decreasing
its effectiveness in the brain (though this is less of an issue
when combined with carbidopa, it is still generally discouraged
without provider approval).
Learning Objective
• Educate patients on expected, harmless adverse effects of
levodopa/carbidopa.
• Identify dietary interactions that decrease levodopa
efficacy.
