NCLEX-RN Pharmacology Practice Questions:
Infection (Antibiotics, Antifungals & Antivirals)
| 20 Original NGN-Style MCQs with Rationales
Question 1
Clinical Scenario
A 72-year-old female client is admitted to the medical-surgical
unit with urosepsis. The healthcare provider orders ceftriaxone
1 g IV every 12 hours. The nurse reviews the client's electronic
health record and notes a documented allergy to penicillin with
a history of anaphylaxis. The client's vital signs are: temperature
101.8°F, heart rate 98 bpm, blood pressure 112/68 mmHg,
respiratory rate 20/min, and oxygen saturation 95% on room air.
Question Stem
Which action should the nurse take first?
A. Administer the ceftriaxone as prescribed and monitor for
allergic reaction.
B. Contact the healthcare provider to request an alternative
antibiotic.
,C. Administer diphenhydramine 25 mg IV prior to the
ceftriaxone infusion.
D. Administer a test dose of ceftriaxone and observe for 30
minutes.
Correct Answer: B. Contact the healthcare provider to request
an alternative antibiotic.
Detailed Rationale
The correct answer is to contact the healthcare provider to
request an alternative antibiotic. Ceftriaxone is a third-
generation cephalosporin antibiotic that shares structural
similarities with penicillins, creating a risk of cross-reactivity in
clients with true penicillin allergy. The cross-reactivity rate
between cephalosporins and penicillins is approximately 5-10%,
but the risk is higher in clients with a history of anaphylaxis to
penicillin. Given this client's documented anaphylactic reaction,
the safest approach is to avoid ceftriaxone entirely and request
an alternative antibiotic from a different class, such as a
fluoroquinolone, aminoglycoside, or vancomycin, depending on
the susceptibility of the infecting organism. The nurse should
clearly communicate the allergy history and the need for an
alternative to the healthcare provider.
,Option A is incorrect because administering a cephalosporin to
a client with a history of anaphylaxis to penicillin places the
client at unnecessary risk for a life-threatening allergic reaction.
Option C is incorrect because pre-medicating with
diphenhydramine does not prevent anaphylaxis; it only treats
mild allergic symptoms and would provide a false sense of
security. Option D is incorrect because test doses are not
recommended for cephalosporins in clients with penicillin
allergy and could precipitate anaphylaxis. The nurse must
prioritize client safety by preventing potential harm through
appropriate medication reconciliation and provider
communication.
Learning Objective
After completing this question, the learner should be able to:
• Recognize the risk of cross-reactivity between penicillin
and cephalosporin antibiotics.
• Implement appropriate nursing actions for clients with
documented penicillin allergies.
• Collaborate with healthcare providers to select safe
antibiotic alternatives.
Medication Safety Focus: Contraindication/Cross-Reactivity
Question 2
, Clinical Scenario
A 45-year-old male client is prescribed oral metronidazole 500
mg three times daily for a Clostridioides difficile infection.
During the admission assessment, the client reports drinking
two to three beers daily and expresses concern about missing
his alcohol while in the hospital. The nurse is providing
medication education prior to the first dose.
Question Stem
Which statement by the client indicates understanding of the
medication teaching?
A. "I can still have a glass of wine with dinner if I wait two hours
after taking my pill."
B. "I should avoid alcohol while taking this medication and for at
least 48 hours after the last dose."
C. "I can resume drinking alcohol once my diarrhea completely
resolves."
D. "I will need to avoid alcohol only on the days I take the
medication."
Correct Answer: B. "I should avoid alcohol while taking this
medication and for at least 48 hours after the last dose."
Detailed Rationale
Infection (Antibiotics, Antifungals & Antivirals)
| 20 Original NGN-Style MCQs with Rationales
Question 1
Clinical Scenario
A 72-year-old female client is admitted to the medical-surgical
unit with urosepsis. The healthcare provider orders ceftriaxone
1 g IV every 12 hours. The nurse reviews the client's electronic
health record and notes a documented allergy to penicillin with
a history of anaphylaxis. The client's vital signs are: temperature
101.8°F, heart rate 98 bpm, blood pressure 112/68 mmHg,
respiratory rate 20/min, and oxygen saturation 95% on room air.
Question Stem
Which action should the nurse take first?
A. Administer the ceftriaxone as prescribed and monitor for
allergic reaction.
B. Contact the healthcare provider to request an alternative
antibiotic.
,C. Administer diphenhydramine 25 mg IV prior to the
ceftriaxone infusion.
D. Administer a test dose of ceftriaxone and observe for 30
minutes.
Correct Answer: B. Contact the healthcare provider to request
an alternative antibiotic.
Detailed Rationale
The correct answer is to contact the healthcare provider to
request an alternative antibiotic. Ceftriaxone is a third-
generation cephalosporin antibiotic that shares structural
similarities with penicillins, creating a risk of cross-reactivity in
clients with true penicillin allergy. The cross-reactivity rate
between cephalosporins and penicillins is approximately 5-10%,
but the risk is higher in clients with a history of anaphylaxis to
penicillin. Given this client's documented anaphylactic reaction,
the safest approach is to avoid ceftriaxone entirely and request
an alternative antibiotic from a different class, such as a
fluoroquinolone, aminoglycoside, or vancomycin, depending on
the susceptibility of the infecting organism. The nurse should
clearly communicate the allergy history and the need for an
alternative to the healthcare provider.
,Option A is incorrect because administering a cephalosporin to
a client with a history of anaphylaxis to penicillin places the
client at unnecessary risk for a life-threatening allergic reaction.
Option C is incorrect because pre-medicating with
diphenhydramine does not prevent anaphylaxis; it only treats
mild allergic symptoms and would provide a false sense of
security. Option D is incorrect because test doses are not
recommended for cephalosporins in clients with penicillin
allergy and could precipitate anaphylaxis. The nurse must
prioritize client safety by preventing potential harm through
appropriate medication reconciliation and provider
communication.
Learning Objective
After completing this question, the learner should be able to:
• Recognize the risk of cross-reactivity between penicillin
and cephalosporin antibiotics.
• Implement appropriate nursing actions for clients with
documented penicillin allergies.
• Collaborate with healthcare providers to select safe
antibiotic alternatives.
Medication Safety Focus: Contraindication/Cross-Reactivity
Question 2
, Clinical Scenario
A 45-year-old male client is prescribed oral metronidazole 500
mg three times daily for a Clostridioides difficile infection.
During the admission assessment, the client reports drinking
two to three beers daily and expresses concern about missing
his alcohol while in the hospital. The nurse is providing
medication education prior to the first dose.
Question Stem
Which statement by the client indicates understanding of the
medication teaching?
A. "I can still have a glass of wine with dinner if I wait two hours
after taking my pill."
B. "I should avoid alcohol while taking this medication and for at
least 48 hours after the last dose."
C. "I can resume drinking alcohol once my diarrhea completely
resolves."
D. "I will need to avoid alcohol only on the days I take the
medication."
Correct Answer: B. "I should avoid alcohol while taking this
medication and for at least 48 hours after the last dose."
Detailed Rationale
