,NU 160 Exam 3 | Comprehensive Questions &
Verified Answers | 2026 Edition | Galen College
1. Which of the following best describes the mechanism of action of penicillins?
A) Inhibition of bacterial cell wall synthesis
B) Inhibition of protein synthesis via 30S ribosomal binding
C) Inhibition of DNA gyrase
D) Disruption of cell membrane integrity
Correct Answer: Inhibition of bacterial cell wall synthesis
Rationale: Penicillins bind to penicillin-binding proteins and block transpeptidation of peptidoglycan,
causing cell wall lysis. They do not directly affect protein synthesis, DNA gyrase, or the cell membrane.
2. The nurse is teaching a patient with a history of penicillin allergy who requires a cephalosporin. Which
instruction is most important?
A) “You cannot receive any cephalosporin because of your allergy.”
B) “A small risk of cross-sensitivity exists; report any rash or itching immediately.”
C) “Take a double dose of antihistamine before the infusion.”
D) “Cephalosporins are completely safe in penicillin allergy.”
Correct Answer: “A small risk of cross-sensitivity exists; report any rash or itching immediately.”
Rationale: Approximately 1–10% of penicillin-allergic patients may also react to cephalosporins. The
nurse must educate the patient to monitor for and immediately report any signs of allergic reaction.
3. The nurse is monitoring a patient receiving erythromycin. Which adverse effect warrants immediate
attention?
A) Nausea and vomiting
B) Diarrhea
,C) Prolonged QT interval
D) Headache
Correct Answer: Prolonged QT interval
Rationale: Macrolides such as erythromycin can prolong the QT interval, increasing the risk of torsades
de pointes. Nausea and diarrhea are common but less urgent; an ECG should be monitored.
4. The nurse is teaching a patient prescribed doxycycline. Which statement by the patient indicates
understanding?
A) “I will take this medication with a glass of milk.”
B) “I can lie down immediately after taking the dose.”
C) “I will protect my skin from sun exposure and avoid dairy products.”
D) “I will stop the antibiotic when my symptoms improve.”
Correct Answer: “I will protect my skin from sun exposure and avoid dairy products.”
Rationale: Tetracyclines cause photosensitivity and bind to calcium in dairy, decreasing absorption. The
patient must avoid sun exposure, take on an empty stomach with water, and remain upright for 30
minutes.
5. The nurse is monitoring a patient receiving gentamicin. Which combination of adverse effects is of
greatest concern?
A) Nephrotoxicity and ototoxicity
B) Hepatotoxicity and cardiotoxicity
C) Pulmonary toxicity and nephrotoxicity
D) Ototoxicity and hepatotoxicity
Correct Answer: Nephrotoxicity and ototoxicity
, Rationale: Aminoglycosides like gentamicin are known for causing acute kidney injury and irreversible
hearing or balance loss. Peak and trough levels are monitored to minimize these risks.
6. The nurse is teaching a patient prescribed ciprofloxacin. Which adverse effect should the patient
report immediately?
A) Dry mouth
B) Tendon pain or swelling
C) Increased appetite
D) Constipation
Correct Answer: Tendon pain or swelling
Rationale: Fluoroquinolones carry a risk of tendonitis and tendon rupture, particularly in older adults
and those on corticosteroids. Any tendon pain must be reported promptly.
7. The nurse is teaching a patient about trimethoprim-sulfamethoxazole. Which instruction is correct?
A) “Restrict fluid intake to prevent diuresis.”
B) “Take the medication on an empty stomach only.”
C) “Drink at least 2–3 liters of fluid daily to prevent crystalluria.”
D) “Avoid all fruits while taking this medication.”
Correct Answer: “Drink at least 2–3 liters of fluid daily to prevent crystalluria.”
Rationale: Sulfonamides can precipitate in the urine, forming crystals. Adequate hydration maintains
high urine flow and prevents kidney stones.
8. The nurse is counseling a patient prescribed metronidazole. Which statement indicates a need for
further teaching?
A) “I will take the medication with food if stomach upset occurs.”
B) “I will use a barrier method if needed because the drug may reduce birth control pill effectiveness.”
Verified Answers | 2026 Edition | Galen College
1. Which of the following best describes the mechanism of action of penicillins?
A) Inhibition of bacterial cell wall synthesis
B) Inhibition of protein synthesis via 30S ribosomal binding
C) Inhibition of DNA gyrase
D) Disruption of cell membrane integrity
Correct Answer: Inhibition of bacterial cell wall synthesis
Rationale: Penicillins bind to penicillin-binding proteins and block transpeptidation of peptidoglycan,
causing cell wall lysis. They do not directly affect protein synthesis, DNA gyrase, or the cell membrane.
2. The nurse is teaching a patient with a history of penicillin allergy who requires a cephalosporin. Which
instruction is most important?
A) “You cannot receive any cephalosporin because of your allergy.”
B) “A small risk of cross-sensitivity exists; report any rash or itching immediately.”
C) “Take a double dose of antihistamine before the infusion.”
D) “Cephalosporins are completely safe in penicillin allergy.”
Correct Answer: “A small risk of cross-sensitivity exists; report any rash or itching immediately.”
Rationale: Approximately 1–10% of penicillin-allergic patients may also react to cephalosporins. The
nurse must educate the patient to monitor for and immediately report any signs of allergic reaction.
3. The nurse is monitoring a patient receiving erythromycin. Which adverse effect warrants immediate
attention?
A) Nausea and vomiting
B) Diarrhea
,C) Prolonged QT interval
D) Headache
Correct Answer: Prolonged QT interval
Rationale: Macrolides such as erythromycin can prolong the QT interval, increasing the risk of torsades
de pointes. Nausea and diarrhea are common but less urgent; an ECG should be monitored.
4. The nurse is teaching a patient prescribed doxycycline. Which statement by the patient indicates
understanding?
A) “I will take this medication with a glass of milk.”
B) “I can lie down immediately after taking the dose.”
C) “I will protect my skin from sun exposure and avoid dairy products.”
D) “I will stop the antibiotic when my symptoms improve.”
Correct Answer: “I will protect my skin from sun exposure and avoid dairy products.”
Rationale: Tetracyclines cause photosensitivity and bind to calcium in dairy, decreasing absorption. The
patient must avoid sun exposure, take on an empty stomach with water, and remain upright for 30
minutes.
5. The nurse is monitoring a patient receiving gentamicin. Which combination of adverse effects is of
greatest concern?
A) Nephrotoxicity and ototoxicity
B) Hepatotoxicity and cardiotoxicity
C) Pulmonary toxicity and nephrotoxicity
D) Ototoxicity and hepatotoxicity
Correct Answer: Nephrotoxicity and ototoxicity
, Rationale: Aminoglycosides like gentamicin are known for causing acute kidney injury and irreversible
hearing or balance loss. Peak and trough levels are monitored to minimize these risks.
6. The nurse is teaching a patient prescribed ciprofloxacin. Which adverse effect should the patient
report immediately?
A) Dry mouth
B) Tendon pain or swelling
C) Increased appetite
D) Constipation
Correct Answer: Tendon pain or swelling
Rationale: Fluoroquinolones carry a risk of tendonitis and tendon rupture, particularly in older adults
and those on corticosteroids. Any tendon pain must be reported promptly.
7. The nurse is teaching a patient about trimethoprim-sulfamethoxazole. Which instruction is correct?
A) “Restrict fluid intake to prevent diuresis.”
B) “Take the medication on an empty stomach only.”
C) “Drink at least 2–3 liters of fluid daily to prevent crystalluria.”
D) “Avoid all fruits while taking this medication.”
Correct Answer: “Drink at least 2–3 liters of fluid daily to prevent crystalluria.”
Rationale: Sulfonamides can precipitate in the urine, forming crystals. Adequate hydration maintains
high urine flow and prevents kidney stones.
8. The nurse is counseling a patient prescribed metronidazole. Which statement indicates a need for
further teaching?
A) “I will take the medication with food if stomach upset occurs.”
B) “I will use a barrier method if needed because the drug may reduce birth control pill effectiveness.”
