Question 1

A child with otitis media has had three ear infections in the past year. The child has just completed a 10-day course of amoxicillin [Amoxil] with no improvement. The parent asks the nurse why this drug is not working, because it has worked in the past. What will the nurse tell the patient?

A) "Amoxicillin is too narrow in spectrum."
B) "The bacteria have developed a three-layer cell envelope."
C) "The bacteria have developed penicillin-binding proteins (PBPs) that have a low affinity for penicillins."
D) "The bacteria have synthesized penicillinase."

"The bacteria have synthesized penicillinase."

Accepted Answer

Beta-lactamases are enzymes that cleave the beta-lactam ring and render the PCN inactive. This resistance is common with organisms that cause ear infections. Amoxicillin is a broad-spectrum antibiotic. A three-layer cell envelope occurs in gram-negative bacteria. Some bacterial strains, including methicillin-resistant Staphylococcus aureus (MRSA), develop PBPs with a low affinity for penicillins. MRSA is not a common cause of otitis media.

Question 2

A patient is about to receive penicillin G for an infection that is highly sensitive to this drug. While obtaining the patient's medication history, the nurse learns that the patient experienced a rash when given amoxicillin [Amoxil] as a child 20 years earlier. What will the nurse do?

A) Ask the provider to order a cephalosporin.
B) Reassure the patient that allergic responses diminish over time.
C) Request an order for a skin test to assess the current risk.
D) Suggest using a desensitization schedule to administer the drug.

Accepted Answer

Allergy to penicillin can decrease over time; therefore, in patients with a previous allergic reaction who need to take penicillin, skin tests can be performed to assess the current risk. Until this risk is known, changing to a cephalosporin is not necessary. Reassuring the patient that allergic responses will diminish is not correct, because this is not always the case; the occurrence of a reaction must be confirmed with skin tests. Desensitizing schedules are used when patients are known to be allergic and the drug is required anyway.

Question 3

A patient with an infection caused by P. aeruginosa is being treated with piperacillin. The nurse providing care reviews the patient's laboratory reports and notes that the patient's blood urea nitrogen and serum creatinine levels are elevated. The nurse will contact the provider to discuss:

A) adding an aminoglycoside.
B) changing to penicillin G.
C) reducing the dose of piperacillin.
D) ordering nafcillin.

Accepted Answer

Patients with renal impairment should receive lower doses of piperacillin than patients with normal renal function. Aminoglycosides are nephrotoxic. Penicillin G and nafcillin are not effective against Pseudomonas infections.

Question 4

A nurse assisting a nursing student with medications asks the student to describe how penicillins (PCNs) work to treat bacterial infections. The student is correct in responding that penicillins:&#10;A) disinhibit transpeptidases.&#10;B) disrupt bacterial cell wall synthesis.&#10;C) inhibit autolysins.&#10;D) inhibit host cell wall function.

Accepted Answer

PCNs weaken the cell wall, causing bacteria to take up excessive amounts of water and subsequently rupture. PCNs inhibit transpeptidases and disinhibit autolysins. PCNs do not affect the cell walls of the host.

Question 5

A patient is receiving intravenous potassium penicillin G, 2 million units to be administered over 1 hour. At 1900, the nurse notes that the dose hung at 1830 has infused completely. What will the nurse do?

A) Assess the skin at the infusion site for signs of tissue necrosis.
B) Observe the patient closely for confusion and other neurotoxic effects.
C) Request an order for serum electrolytes and cardiac monitoring.
D) Watch the patient's actions and report any bizarre behaviors.

Accepted Answer

Although penicillin G is the least toxic of all antibiotics, certain adverse effects may be caused by compounds coadministered with penicillin. When large doses of potassium penicillin G are administered rapidly, hyperkalemia can occur, which can cause fatal dysrhythmias. When penicillin G is administered IM, tissue necrosis occurs with inadvertent intra-arterial injection. Confusion, seizures, and hallucinations can occur if blood levels of the drug are too high. Bizarre behaviors result with large IV doses of procaine penicillin G.

Question 6

A patient with no known drug allergies is receiving amoxicillin [Amoxil] PO twice daily. Twenty minutes after being given a dose, the patient complains of shortness of breath. The patient's blood pressure is 100/58 mm Hg. What will the nurse do?

A) Contact the provider and prepare to administer epinephrine.
B) Notify the provider if the patient develops a rash.
C) Request an order for a skin test to evaluate possible PCN allergy.
D) Withhold the next dose until symptoms subside.

Accepted Answer

This patient is showing signs of an immediate penicillin allergy, that is, one that occurs within 2 to 30 minutes after administration of the drug. The patient is showing signs of anaphylaxis, which include laryngeal edema, bronchoconstriction, and hypotension; these must be treated with epinephrine. This is an emergency, and the provider must be notified immediately, not when other symptoms develop. It is not necessary to order skin testing. The patient must be treated immediately, and subsequent doses should not be given.

Question 7

The parent of an infant with otitis media asks the nurse why the prescriber has ordered amoxicillin [Amoxil] and not ampicillin [Unasyn]. What will the nurse tell the parent?&#10;A) Amoxicillin is a broader spectrum antibiotic than ampicillin.&#10;B) Amoxicillin is not inactivated by beta-lactamases.&#10;C) Ampicillin is associated with more allergic reactions.&#10;D) Ampicillin is not as acid stable as amoxicillin.

Accepted Answer

Amoxicillin and ampicillin are similar in structure and actions but differ primarily in acid stability. Amoxicillin is more acid stable and, when administered orally, results in higher blood levels than can be obtained with equivalent doses of ampicillin. The two drugs have the same spectrum, both are inactivated by beta-lactamases, and both can cause allergic reactions.

Question 8

Which organisms can be treated with penicillin G (Benzylpenicillin)?&#10;A) Methicillin-resistant S. aureus&#10;B) Neisseria meningitidis&#10;C) P. aeruginosa&#10;D) S. pyogenes&#10;E) T. pallidum

Accepted Answer

Penicillin G is the first drug of choice for N. meningitidis. It is a drug of first choice for infections caused by sensitive gram-positive cocci, including S. pyogenes. It is a drug of choice for T. pallidum. It is not effective against methicillin-resistant S. aureus or P. aeruginosa.

Question 9

A nurse is preparing to administer intramuscular penicillin to a patient who is infected with Treponema pallidum and notes that the order is for sodium penicillin G. Which action is correct?&#10;A) Administer the drug as prescribed.&#10;B) Contact the provider to discuss administering the drug intravenously.&#10;C) Contact the provider to discuss changing the drug to benzathine penicillin G.&#10;D) Request an order for piperacillin instead of penicillin G.

Accepted Answer

Procaine and benzathine penicillin salts are absorbed slowly and are considered repository preparations. When benzathine penicillin G is injected IM, penicillin G is absorbed for weeks and is useful only against highly sensitive organisms such as Treponema pallidum. Sodium penicillin G is absorbed rapidly, with peak effects in 15 minutes. Administering the drug IV will not yield repository effects. Piperacillin is not used for Treponema pallidum IC.

Question 10

A nursing student wants to know the differences between hospital-associated methicillin-resistant S. aureus (HA-MRSA) and community-associated methicillin-resistant S. aureus (CA-MRSA). Which statements about CA-MRSA are true?

A) 20% to 30% of the general population are colonized with CA-MRSA.
B) Boils caused by CA-MRSA can be treated without antibiotics.
C) CA-MRSA is less dangerous than HA-MRSA.
D) CA-MRSA does not cause necrotizing fasciitis.
E) CA-MRSA is transmitted by airborne droplets.

Accepted Answer

CA-MRSA is thought to be present in 20% to 30% of the population, and many of these individuals are asymptomatic carriers. Boils caused by CA-MRSA can often be treated by surgical drainage alone. CA-MRSA is less dangerous than HA-MRSA but more dangerous than methicillin-sensitive S. aureus (MSSA). CA-MRSA generally causes mild skin infections but can cause more serious infections, such as necrotizing fasciitis. CA-MRSA is transmitted by skin-to-skin contact and by contact with contaminated objects.

Question 11

A patient has an infection caused by Streptococcus pyogenes. The prescriber has ordered dicloxacillin PO. What will the nurse do?&#10;A) Administer the medication as ordered.&#10;B) Contact the provider to suggest giving the drug IV.&#10;C) Question the need for a penicillinase-resistant penicillin.&#10;D) Suggest ordering vancomycin to treat this infection.

Accepted Answer

The answer of A patient has an infection caused by...

Question 12

A nurse transcribes a new prescription for potassium penicillin G given intravenously (IV) every 8 hours and gentamicin given IV every 12 hours. Which is the best schedule for administering these drugs?

A) Give the penicillin at 0800, 1600, and 2400; give the gentamicin [Garamycin] at 1800 and 0600.
B) Give the penicillin at 0800, 1600, and 2400; give the gentamicin [Garamycin] at 1200 and 2400.
C) Give the penicillin at 0600, 1400, and 2200; give the gentamicin [Garamycin] at 0600 and 1800.
D) Give the penicillin every 8 hours; give the gentamicin [Garamycin] simultaneously with two of the penicillin doses.

Accepted Answer

The answer of A nurse transcribes a new prescription for...

Question 13

A nurse is discussing methicillin-resistant S. aureus (MRSA) with a group of nursing students. Which statement by a student correctly identifies the basis for MRSA resistance?&#10;A) &#34;MRSA bacteria have developed PBPs with a low affinity for penicillins.&#34;&#10;B) &#34;MRSA bacteria produce penicillinases that render penicillin ineffective.&#34;&#10;C) &#34;MRSA occurs because of host resistance to penicillins.&#34;&#10;D) &#34;MRSA strains replicate faster than other S. aureus strains.&#34;

Accepted Answer

The answer of A nurse is discussing methicillin-resistant S. aureus...

Question 14

A patient has an infection caused by Pseudomonas aeruginosa. The prescriber has ordered piperacillin and amikacin, both to be given intravenously. What will the nurse do?&#10;A) Make sure to administer the drugs at different times using different IV tubing.&#10;B) Suggest giving larger doses of piperacillin and discontinuing the amikacin.&#10;C) Suggest that a fixed-dose combination of piperacillin and tazobactam [Zosyn] be used.&#10;D) Watch the patient closely for allergic reactions, because this risk is increased with this combination.

Accepted Answer

The answer of A patient has an infection caused by...

Question 15

A child with an ear infection is not responding to treatment with amoxicillin [Amoxil]. The nurse will expect the provider to order:&#10;A) amoxicillin-clavulanic acid [Augmentin].&#10;B) ampicillin.&#10;C) nafcillin.&#10;D) penicillin G [Benzylpenicillin].

Accepted Answer

The answer of A child with an ear infection is...

Deck 84: Drugs That Weaken the Bacterial Cell Wall I: Penicillins