Antibiotic Principles
A patient arrives in the ED department with suspected bacterial meningitis. Blood cultures are obtained, and the provider immediately starts IV antibiotics before culture results are available. What type of therapy is being used?
A. Definitive therapy
B. Prophylactic therapy
C. Empiric therapy
Answer: C. Empiric therapy
Rationale: Empiric therapy is started before the specific organism and its antibiotic sensitivities are known. The provider chooses an antibiotic based on the suspected infection, likely organisms, and the seriousness of the patient’s condition. Once the culture and sensitivity results are available, treatment may be changed to definitive therapy.
How do penicillin antibiotics cause bacterial cell death?
A. They prevent the bacteria from building a stable cell wall.
B. They block the bacteria from producing folic acid.
C. They stop the bacteria from making proteins.
Answer: A
Rationale: Penicillins interfere with bacterial cell-wall formation. Without a strong cell wall, the bacteria can rupture and die.
Which antibiotic belongs to the macrolide class?
A. Azithromycin
B. Ceftriaxone
C. Ciprofloxacin
Answer: A
Rationale: Azithromycin is a macrolide antibiotic. A helpful clue is the "-thromycin" suffix used by macrolides.
Which medication suffix is commonly associated with fluoroquinolone antibiotics?
A. -cycline
B. -floxacin
C. -azole
Answer: B
Rationale: Fluoroquinolone antibiotics commonly end in "-floxacin" (ex: ciprofloxacin, levofloxacin).
A patient receiving gentamicin has today's lab results available. Which result should the nurse review most carefully before administering the next dose?
A. Creatinine level
B. Hemoglobin level
C. Platelet count
Answer: A
Rationale: Gentamicin can cause nephrotoxicity, so kidney function should be assessed before administering medication.
A patient has been taking a broad-spectrum antibiotic for 5 days. C&S results identify the specific bacteria causing the infection and show it is susceptible to a narrow-spectrum antibiotic. What is the nurse's best expectation?
A. Continue the broad-spectrum antibiotic until the Rx is complete.
B. Discontinue the antibiotics because the organism has been identified.
C. Change to narrow-spectrum that specifically targets the identified bacteria.
Answer: C
Rationale: Once C&S results identify the organism, therapy should be changed to the most targeted antibiotic. This helps treat the infection while reducing unnecessary antibiotic exposure and resistance.
A patient with a history of severe anaphylaxis to penicillin is prescribed ceftriaxone. What should the nurse do first?
A. Administer the medication as ordered.
B. Clarify the order with the provider before administering.
C. Give diphenhydramine before administering the antibiotic.
Answer: B
Rationale: Although the risk of cross-reactivity between penicillins and cephalosporins is low (~1-2%). Cephalosporins should be avoided in patient with a severe or anaphylactic penicillin allergy. Orders should be clarified.
A patient is receiving gentamicin. Which assessment finding should the nurse report to the provider immediately?
A. Ringing in the ears and decreased hearing
B. Nausea after the first dose
C. Decreased appetite
Answer: A
Rationale: Gentamicin can cause ototoxicity, which may present as tinnitus, hearing loss or balance problems. These symptoms should be reported immediately because they may indicate permanent damage if the medication is continued.
A patient is prescribed ciprofloxacin. Which statement by the patient indicates a need for further teaching?
A. "I'll call my provider if I develop sudden pain in my Achilles tendon."
B. "I'll take my medication with milk to help prevent stomach upset."
C. "I'll wear sunscreen and protective clothing when I am outside."
Answer: B
Rationale: Ciprofloxacin should not be taken with dairy products or calcium-containing products because they can reduce absorption of the medication. Separate cations (Ca / Mg / Al / Fe / Zn) 2 h before / 6 h after.
A provider prescribes nitrofurantoin for a patient diagnosed with pyelonephritis (kidney infection). What should the nurse do?
A. Administer the medication as ordered.
B. Clarify the order with the provider.
C. Instruct the patient to take medication with food.
Answer: B
Rationale: Nitrofurantoin only reaches therapeutic levels in the urine, so it is appropriate for uncomplicated cystitis (bladder infection) but not pyelonephritis. The nurse should question the order.
A patient is prescribed trimethoprim-sulfamethoxazole (TMP-SMX). Which statement correctly describes how this medication works?
A. It inhibits bacterial cell wall synthesis
B. It blocks bacterial folate synthesis
C. It damages bacterial DNA
Correct answer: B
Rationale: TMP-SMX works by blocking bacterial folate synthesis, preventing bacteria from making the DNA, RNA and protein needed for growth. The other answers describe different ways antibiotics kill or stop bacteria from growing.
A patient is receiving IV vancomycin. Ten minutes into the infusion, the patient develops flushing, itching and redness on the face and neck. The patient's breathing and blood pressure remain stable. What is the nurses's priority action?
A. Stop the infusion, notify the provider and prepare to administer epinephrine.
B. Stop the infusion and administer an antihistamine as ordered.
C. Continue the infusion because these are expected side effects.
Answer: B
Rationale: The patient is experiencing a vancomycin infusion reaction (Red Man Syndrome) caused by rapid infusion. The nurse should first stop the infusion and administer an antihistamine as ordered. Once symptoms resolve, vancomycin may be restarted at a slower rate.
A patient has been taking clindamycin for one week. Which statement by the patient requires immediate follow-up by the nurse?
A. "I've noticed a mild headache since starting the medication."
B. "I take each dose with a glass of milk to prevent upset stomach."
C. "I've had frequent watery stools and abdominal cramping since yesterday."
Answer: C
Rationale: Frequent watery diarrhea and abdominal cramping may indicate C. difficile, a serious adverse effect of clindamycin. The patient should stop the medication and contact the healthcare provider promptly.
A 68-year-old patient has been taking ciprofloxacin for 5 days. Which statement requires the nurse's immediate follow-up?
A. "I've noticed sudden pain in the back of my ankle when I walk today."
B. "I took my antacid at the same time as my antibiotic."
C. I've had mild nausea since starting my medication and it won't go away."
Answer: A
Rationale: Sudden tendon pain may be an early sign of tendonitis or tendon rupture, a serious adverse effect of fluoroquinolones. The medication should be stopped immediately. Taking antacids should require further teaching, but not immediate concern. Mild nausea is a common side effect, not an emergency.
Which finding in a patient taking trimethoprim-sulfamethoxazole requires immediate nursing follow-up?
A. Blistering rash with peeling skin
B. Mild nausea and decreased appetite during the first day of treatment
C. Mild redness after several hours in the sun
Answer: A
Rationale: Blistering and peeling skin may indicate Steven-Johnsons syndrome, a rare but serious reaction to trimethoprim-sulfamethoxazole. Medication should be stopped and the patient needs immediate medical evaluation.
A nursing student is studying antibiotic classes with their mechanisms. Which pairing is correct?
A. Penicillins - inhibits protein synthesis
B. Macrolides - inhibit protein synthesis
C. Fluoroquinolones - inhibit DNA replication
Answer: B
Rationale: Fluoroquinolones inhibit bacterial DNA replication, preventing bacteria from growing and reproducing.
Which cephalosporin generation is active against MRSA?
A. First generation
B. Second generation
C. Third generation
D. Fourth generation
E. Fifth generation
Rationale: Fifth-generation cephalosporins are the only cephalosporins with activity against MRSA. They also have broader gram-negative coverage than earlier generations.
A client is prescribed linezolid (Zyvox). Which food should the nurse instruct the client to avoid?
A. Milk
B. Grapefruit juice
C. Aged cheese
Answer: C
Rationale: Linezolid can interact with tyramine-rich foods, such as aged cheese, cured/smoked meats, tap beer, wine.
A patient who regularly drinks alcohol is prescribed metronidazole (Flagyl). Which instruction is most important?
A. Avoid alcohol during treatment and for 3 days after last dose.
B. Limit alcohol to one drink per day.
C. Alcohol is safe if taken several hours after the medication.
Answer: A
Rationale: Metronidazole can cause a disulfiram-like reaction when combined with alcohol. Patient should avoid alcohol during treatment and for 3 days after the last dose.
Which symptom should a client taking a broad-spectrum antibiotic report immediately as a possible superinfection?
A. Loss of appetite
B. White patches inside the mouth
C. Headache after taking the medication
Answer: B
Rationale: White patches in the mouth may indicate oral thrush, a superinfection that can occur when antibiotics disrupt normal flora. A patient should report these symptoms to their provider.