,NU 578 U5 Exam | Pharm for Adv Practice Nurses (2026/2027) Q&A | U South
Alabama
1. A patient develops watery diarrhea 7 days after completing a course of clindamycin.
Which organism is most likely responsible?
A) Escherichia coli
B) Clostridioides difficile
C) Salmonella
D) Campylobacter
Correct Answer: Clostridioides difficile
Rationale: Clindamycin is strongly associated with C. difficile infection due to disruption of
normal gut flora, allowing toxin-producing C. difficile to overgrow. This typically presents 5-
10 days after antibiotic completion with watery diarrhea, abdominal pain, and leukocytosis.
Other organisms listed do not have this specific association with clindamycin.
2. Which antibiotic is safe to use in a patient with a true penicillin anaphylaxis?
A) Cephalexin
B) Ampicillin
C) Azithromycin
D) Amoxicillin-clavulanate
Correct Answer: Azithromycin
Rationale: Macrolides like azithromycin have no cross-reactivity with penicillins and are
safe in patients with true penicillin anaphylaxis. Cephalosporins carry a cross-reactivity risk
of approximately 1% and should be avoided if possible. Ampicillin and amoxicillin-
clavulanate are penicillins and are contraindicated.
3. A patient on warfarin develops an INR of 5.0 after starting a new antibiotic. Which
antibiotic is most likely responsible?
,A) Azithromycin
B) Ciprofloxacin
C) Ampicillin
D) Doxycycline
Correct Answer: Ciprofloxacin
Rationale: Fluoroquinolones like ciprofloxacin inhibit CYP1A2 and can significantly
potentiate warfarin's anticoagulant effect, leading to elevated INR and bleeding risk.
Azithromycin, ampicillin, and doxycycline have less significant interactions with warfarin.
Close INR monitoring is essential when adding any antibiotic to warfarin therapy.
4. A patient with a sulfa allergy requires treatment for uncomplicated cystitis. Which
antibiotic is most appropriate?
A) Trimethoprim-sulfamethoxazole
B) Nitrofurantoin
C) Ciprofloxacin
D) Amoxicillin
Correct Answer: Nitrofurantoin
Rationale: Nitrofurantoin is first-line for uncomplicated cystitis and has no cross-reactivity
with sulfonamides. TMP-SMX is contraindicated due to sulfa allergy. Fluoroquinolones are
reserved for complicated infections due to resistance concerns. Amoxicillin is not first-line
for cystitis.
5. Which antibiotic requires dose adjustment in both renal and hepatic impairment?
A) Ceftriaxone
B) Doxycycline
C) Rifampin
D) Tetracycline
Correct Answer: Rifampin
, Rationale: Rifampin is metabolized in the liver and excreted via bile and urine. Dose
adjustment is needed in both severe hepatic impairment (due to metabolism) and renal
impairment (due to accumulation of active metabolites). Ceftriaxone, doxycycline, and
tetracycline do not require dual adjustment.
6. A patient develops red man syndrome during intravenous vancomycin infusion. What is
the most appropriate next action?
A) Stop the infusion immediately
B) Slow the infusion rate and administer diphenhydramine
C) Push intravenous epinephrine
D) Switch to oral vancomycin
Correct Answer: Slow the infusion rate and administer diphenhydramine
Rationale: Red man syndrome is a histamine-mediated reaction caused by rapid
vancomycin infusion. Slowing the infusion rate (over >1 hour) and giving an antihistamine
like diphenhydramine resolves symptoms. Stopping the infusion entirely is not necessary.
Epinephrine is for anaphylaxis, not red man syndrome.
7. A patient on metronidazole reports flushing, nausea, and palpitations after drinking wine.
What is this reaction called?
A) Anaphylaxis
B) Serotonin syndrome
C) Disulfiram-like reaction
D) Histamine release
Correct Answer: Disulfiram-like reaction
Rationale: Metronidazole inhibits aldehyde dehydrogenase, causing acetaldehyde
accumulation when alcohol is consumed — identical to the disulfiram (Antabuse) reaction.
Symptoms include flushing, nausea, vomiting, tachycardia, and hypotension. Patients should
be advised to avoid alcohol during therapy and for 3 days after.
Alabama
1. A patient develops watery diarrhea 7 days after completing a course of clindamycin.
Which organism is most likely responsible?
A) Escherichia coli
B) Clostridioides difficile
C) Salmonella
D) Campylobacter
Correct Answer: Clostridioides difficile
Rationale: Clindamycin is strongly associated with C. difficile infection due to disruption of
normal gut flora, allowing toxin-producing C. difficile to overgrow. This typically presents 5-
10 days after antibiotic completion with watery diarrhea, abdominal pain, and leukocytosis.
Other organisms listed do not have this specific association with clindamycin.
2. Which antibiotic is safe to use in a patient with a true penicillin anaphylaxis?
A) Cephalexin
B) Ampicillin
C) Azithromycin
D) Amoxicillin-clavulanate
Correct Answer: Azithromycin
Rationale: Macrolides like azithromycin have no cross-reactivity with penicillins and are
safe in patients with true penicillin anaphylaxis. Cephalosporins carry a cross-reactivity risk
of approximately 1% and should be avoided if possible. Ampicillin and amoxicillin-
clavulanate are penicillins and are contraindicated.
3. A patient on warfarin develops an INR of 5.0 after starting a new antibiotic. Which
antibiotic is most likely responsible?
,A) Azithromycin
B) Ciprofloxacin
C) Ampicillin
D) Doxycycline
Correct Answer: Ciprofloxacin
Rationale: Fluoroquinolones like ciprofloxacin inhibit CYP1A2 and can significantly
potentiate warfarin's anticoagulant effect, leading to elevated INR and bleeding risk.
Azithromycin, ampicillin, and doxycycline have less significant interactions with warfarin.
Close INR monitoring is essential when adding any antibiotic to warfarin therapy.
4. A patient with a sulfa allergy requires treatment for uncomplicated cystitis. Which
antibiotic is most appropriate?
A) Trimethoprim-sulfamethoxazole
B) Nitrofurantoin
C) Ciprofloxacin
D) Amoxicillin
Correct Answer: Nitrofurantoin
Rationale: Nitrofurantoin is first-line for uncomplicated cystitis and has no cross-reactivity
with sulfonamides. TMP-SMX is contraindicated due to sulfa allergy. Fluoroquinolones are
reserved for complicated infections due to resistance concerns. Amoxicillin is not first-line
for cystitis.
5. Which antibiotic requires dose adjustment in both renal and hepatic impairment?
A) Ceftriaxone
B) Doxycycline
C) Rifampin
D) Tetracycline
Correct Answer: Rifampin
, Rationale: Rifampin is metabolized in the liver and excreted via bile and urine. Dose
adjustment is needed in both severe hepatic impairment (due to metabolism) and renal
impairment (due to accumulation of active metabolites). Ceftriaxone, doxycycline, and
tetracycline do not require dual adjustment.
6. A patient develops red man syndrome during intravenous vancomycin infusion. What is
the most appropriate next action?
A) Stop the infusion immediately
B) Slow the infusion rate and administer diphenhydramine
C) Push intravenous epinephrine
D) Switch to oral vancomycin
Correct Answer: Slow the infusion rate and administer diphenhydramine
Rationale: Red man syndrome is a histamine-mediated reaction caused by rapid
vancomycin infusion. Slowing the infusion rate (over >1 hour) and giving an antihistamine
like diphenhydramine resolves symptoms. Stopping the infusion entirely is not necessary.
Epinephrine is for anaphylaxis, not red man syndrome.
7. A patient on metronidazole reports flushing, nausea, and palpitations after drinking wine.
What is this reaction called?
A) Anaphylaxis
B) Serotonin syndrome
C) Disulfiram-like reaction
D) Histamine release
Correct Answer: Disulfiram-like reaction
Rationale: Metronidazole inhibits aldehyde dehydrogenase, causing acetaldehyde
accumulation when alcohol is consumed — identical to the disulfiram (Antabuse) reaction.
Symptoms include flushing, nausea, vomiting, tachycardia, and hypotension. Patients should
be advised to avoid alcohol during therapy and for 3 days after.
