STUVIA 2024/2025
Chapter 26: Antibacterials
The nurse is caring for a patient who is receiving an intravenous antibiotic. The nurse notes that the
provider has ordered serum drug peak and trough levels. The nurse understands that these tests are
necessary for which type of drugs?
a. Drugs with a broad spectrum
b. Drugs with a narrow spectrum
c. Drugs with a broad therapeutic index
d. Drugs with a narrow therapeutic index - ✔✔ANS: D
Medications with a narrow therapeutic index have a limited range between the therapeutic dose and a
toxic dose. It is important to monitor these medications closely by evaluating regular serum peak and
trough levels.
The nurse is caring for a patient who is receiving an intravenous antibiotic. The patient has a serum
drug trough of 1.5 mcg/mL. The normal trough for this drug is 1.7 to 2.2 mcg/mL. What will the nurse
expect the patient to experience?
a. Inadequate therapeutic effects
b. Increased risk for superinfection
c. Excessive adverse effects
%
d. Signs of drug toxicity - ✔✔ANS: A
Low peak levels indicate that the medication is below the therapeutic level. They do not indicate
altered risk for superinfection. Because drug levels are lower than indicated it would not be expected
to see excessive adverse effects or signs of drug toxicity.
The nurse is teaching a nursing student about the minimal effective concentration (MEC) of
antibiotics. Which statement by the nursing student indicates understanding of this concept?
a. "A serum drug level greater than the MEC ensures that the drug is bacteriostatic."
b. "A serum drug level greater than the MEC broadens the spectrum of the drug."
c. "A serum drug level greater than the MEC is sufficient to halt the growth of the microorganism."
d. "A serum drug level greater than the MEC increases the therapeutic index." - ✔✔ANS: C
The MEC is the minimum amount of drug needed to halt the growth of a microorganism. A level
greater than the MEC helps eradicate infections. Drugs at or above the MEC are usually bactericidal,
not bacteriostatic. Raising the drug level does not usually broaden the spectrum or increase the
therapeutic index of a drug.
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, STUVIA 2024/2025
The nurse is caring for a patient who has recurrent urinary tract infections. The patient's current
infection is not responding to an antibiotic that has been used successfully several times in the past.
The nurse understands that this is most likely due to:
a. acquired bacterial resistance.
b. cross-resistance.
c. inherent bacterial resistance.
d. transferred resistance. - ✔✔ANS: A
Acquired resistance occurs when an organism has been exposed to the antibacterial drug and
becomes resistant over time. Cross-resistance occurs when an organism that is resistant to one drug
is also resistant to another. Inherent resistance occurs without previous exposure to the drug.
Transferred resistance occurs when the resistant genes of one organism are passed to another
organism.
The nurse is preparing to administer amoxicillin (Amoxil) to a patient and learns that the patient
previously experienced a rash when taking penicillin. Which action will the nurse take?
a. Administer the amoxicillin and have epinephrine available.
b. Ask the provider to order an antihistamine.
c. Contact the provider to discuss using a different antibiotic.
d. Request an order for a beta-lactamase resistant drug. - ✔✔ANS: C
%
Patients who have previously experienced manifestations of allergy to a penicillin should not use
penicillins again unless necessary. The nurse should contact the provider to discuss using another
antibiotic from a different class. Epinephrine and antihistamines are useful when patients are
experiencing allergic reactions, depending on severity.
The nurse is preparing to administer an antibiotic to a patient who has been receiving the antibiotic for
2 days after a culture was obtained. The nurse notes increased erythema and swelling, and the
patient has a persistent high fever of 39° C. What is the nurse's next best action?
a. Administer the antibiotic as ordered.
b. Contact the provider to request another culture.
c. Discuss the need to add a second antibiotic with the provider.
d. Review the sensitivity results from the patient's culture. - ✔✔ANS: D
The sensitivity results from the patient's culture will reveal whether the organism is sensitive or
resistant to a particular antibiotic. The patient is not responding to the antibiotic being given, so the
antibiotic should be held and the provider notified. Another culture is not indicated. Antibiotics should
be added only when indicated by the sensitivity.
stuvia
Chapter 26: Antibacterials
The nurse is caring for a patient who is receiving an intravenous antibiotic. The nurse notes that the
provider has ordered serum drug peak and trough levels. The nurse understands that these tests are
necessary for which type of drugs?
a. Drugs with a broad spectrum
b. Drugs with a narrow spectrum
c. Drugs with a broad therapeutic index
d. Drugs with a narrow therapeutic index - ✔✔ANS: D
Medications with a narrow therapeutic index have a limited range between the therapeutic dose and a
toxic dose. It is important to monitor these medications closely by evaluating regular serum peak and
trough levels.
The nurse is caring for a patient who is receiving an intravenous antibiotic. The patient has a serum
drug trough of 1.5 mcg/mL. The normal trough for this drug is 1.7 to 2.2 mcg/mL. What will the nurse
expect the patient to experience?
a. Inadequate therapeutic effects
b. Increased risk for superinfection
c. Excessive adverse effects
%
d. Signs of drug toxicity - ✔✔ANS: A
Low peak levels indicate that the medication is below the therapeutic level. They do not indicate
altered risk for superinfection. Because drug levels are lower than indicated it would not be expected
to see excessive adverse effects or signs of drug toxicity.
The nurse is teaching a nursing student about the minimal effective concentration (MEC) of
antibiotics. Which statement by the nursing student indicates understanding of this concept?
a. "A serum drug level greater than the MEC ensures that the drug is bacteriostatic."
b. "A serum drug level greater than the MEC broadens the spectrum of the drug."
c. "A serum drug level greater than the MEC is sufficient to halt the growth of the microorganism."
d. "A serum drug level greater than the MEC increases the therapeutic index." - ✔✔ANS: C
The MEC is the minimum amount of drug needed to halt the growth of a microorganism. A level
greater than the MEC helps eradicate infections. Drugs at or above the MEC are usually bactericidal,
not bacteriostatic. Raising the drug level does not usually broaden the spectrum or increase the
therapeutic index of a drug.
stuvia
, STUVIA 2024/2025
The nurse is caring for a patient who has recurrent urinary tract infections. The patient's current
infection is not responding to an antibiotic that has been used successfully several times in the past.
The nurse understands that this is most likely due to:
a. acquired bacterial resistance.
b. cross-resistance.
c. inherent bacterial resistance.
d. transferred resistance. - ✔✔ANS: A
Acquired resistance occurs when an organism has been exposed to the antibacterial drug and
becomes resistant over time. Cross-resistance occurs when an organism that is resistant to one drug
is also resistant to another. Inherent resistance occurs without previous exposure to the drug.
Transferred resistance occurs when the resistant genes of one organism are passed to another
organism.
The nurse is preparing to administer amoxicillin (Amoxil) to a patient and learns that the patient
previously experienced a rash when taking penicillin. Which action will the nurse take?
a. Administer the amoxicillin and have epinephrine available.
b. Ask the provider to order an antihistamine.
c. Contact the provider to discuss using a different antibiotic.
d. Request an order for a beta-lactamase resistant drug. - ✔✔ANS: C
%
Patients who have previously experienced manifestations of allergy to a penicillin should not use
penicillins again unless necessary. The nurse should contact the provider to discuss using another
antibiotic from a different class. Epinephrine and antihistamines are useful when patients are
experiencing allergic reactions, depending on severity.
The nurse is preparing to administer an antibiotic to a patient who has been receiving the antibiotic for
2 days after a culture was obtained. The nurse notes increased erythema and swelling, and the
patient has a persistent high fever of 39° C. What is the nurse's next best action?
a. Administer the antibiotic as ordered.
b. Contact the provider to request another culture.
c. Discuss the need to add a second antibiotic with the provider.
d. Review the sensitivity results from the patient's culture. - ✔✔ANS: D
The sensitivity results from the patient's culture will reveal whether the organism is sensitive or
resistant to a particular antibiotic. The patient is not responding to the antibiotic being given, so the
antibiotic should be held and the provider notified. Another culture is not indicated. Antibiotics should
be added only when indicated by the sensitivity.
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