Antibiotics NCLEX Questions & Rationales 2025 LATEST VERSION
C. Ability to avoid injuring host cells
An antimicrobial medication that has selective toxicity has which
Selective toxicity refers to an antibiotic that has the ability to injure
characteristic?
only invading microbes, not the host. Conjugation is the process
A. Ability to transfer DNA coding
through which DNA coding for drug resistance is transferred from
B. Ability to suppress bacterial resistance
one bacterium to another. Antibiotics do not suppress bacterial
C. Ability to avoid injuring host cells
resistance, but rather promote the emergence of drug-resistant
D. Ability to act against a specific microbe
microbes. Antibiotics that are narrow spectrum are active against
only a few microbes.
The development of a new infection as a result of the elimination B. Superinfection
of normal flora by an antibiotic is referred to as what?
A. Resistant infection Antibiotic therapy can destroy the normal flora of the body, which
B. Superinfection normally would inhibit the overgrowth of fungi and yeast. When
C. Nosocomial infection the normal flora is decreased, these organisms can overgrow and
D. Allergic reaction cause a new infection, or superinfection.
D. Transfer of DNA coding to another bacteria
A microbe acquires antibiotic resistance by which means? All alterations in structure and function result from changes in the
A. Development of medication resistance in the host microbial genome. The microbe, not the host, becomes medication
B. Over-riding of the minimum bactericidal concentration resistant. Genetic changes in a microbe result either from spon-
C. Incorrect dosing, which contributes to ribosome mutations taneous mutation or from acquisition of DNA from conjugation
D. Transfer of DNA coding to other bacteria with other bacteria. The minimum bacterial concentration (MBC) is
used in testing for drug sensitivity. Incorrect dosing does not lead
to microbe mutations.
B. Competent immune function
The nurse identifies which host factor as the most important when
choosing an antimicrobial drug? Two factors—host defenses and the site of infection—are unique
A. Age to the selection of antibiotics. It is critical for success that an-
B. Competent immune function tibiotics act synergistically with the immune system to subdue
C. Genetic heritage infection. Other host factors, such as age, genetic heritage, and
D. Previous medication reactions previous drug reactions, are the same factors that must be con-
sidered when choosing any other medication.
B. The lowest concentration of an antibiotic needed to reduce the
What is the minimum bactericidal concentration (MBC)?
number of bacterial colonies by 99.9%
A. The lowest concentration of an antibiotic needed to suppress
bacterial growth completely
B. The lowest concentration of an antibiotic needed to reduce the The MBC is the lowest concentration of drug that produces a
99.9% decline in the number of bacterial colonies (indicating bac-
number of bacterial colonies by 99.9%
terial kill). The lowest antibiotic concentration needed to suppress
C. The lowest concentration of an antibiotic needed to produce
bacterial growth or to produce effects and the lowest antibiotic
effects
dose needed to eradicate bacteria are incorrect descriptions of
D. The lowest dose of an antibiotic needed to eradicate bacteria
MBC.
D. Disk diffusion
Which test is the most widely used method for assessing drug
sensitivity? The most widely used method for assessing drug sensitivity
A. Minimum inhibitory concentration (MIC) is the disk diffusion test, also known as the Kirby-Bauer test.
B. Minimum bacterial concentration (MBC) Through diffusion, an antibiotic-containing zone becomes estab-
C. Broth dilution lished around each disk. As the bacteria proliferate, growth is
D. Disk diffusion inhibited around the disks that contain an antibiotic to which the
bacteria are sensitive.
A nurse removes a central line access device once the patient C. Preventing infection
no longer requires intravenous (IV) antibiotics. This action is an
example of which strategy to prevent antimicrobial resistance The CDC's campaign to prevent the development of antimicrobial
established by the Centers for Disease Control and Prevention resistance in hospitals focuses on four approaches: (1) prevent in-
(CDC)? fection, (2) diagnose and treat infection effectively, (3) use antimi-
A. Preventing transmission crobials wisely, and (4) prevent transmission. Expeditious removal
B. Proper diagnosis of invasive devices, such as IV catheters, and restricting these
C. Preventing infection devices to essential use are examples of the CDC's strategy to
D. Prudent antibiotic use prevent infection.
The nurse identifies what as the first step in the Campaign to Pre-
vent Antimicrobial Resistance, established in 2002 by the CDC?
, Antibiotics NCLEX Questions & Rationales 2025 LATEST VERSION
A. Target the pathogen D. Vaccinate
B. Access the experts
C. Isolate the pathogen Although all responses are components of the Campaign to Pre-
D. Vaccinate vent Antimicrobial Resistance, step one is vaccination.
A patient has acquired an infection while in the hospital. The nurse
C. Nosocomial infection
identifies this type of infection as what?
A. Superinfection
Nosocomial infections are acquired by patients while in the hospi-
B. Suprainfection
tal. Superinfection and suprainfection are terms used to describe
C. Nosocomial infection
the emergence of drug resistance.
D. Resistant infection
B. Reduction of fever
C. Sterile sputum cultures
A nurse is assessing the effects of antimicrobial therapy in a pa- D. Oxygen saturation of 98%
tient with pneumonia. The nurse should establish which outcomes
when planning care? (Select all that apply.) Antimicrobial therapy is assessed by monitoring clinical and lab-
A. Potassium level of 4 mEq/dL oratory responses. Clinical indicators of success in a patient with
B. Reduction of fever pneumonia may include afebrile status and resolution of an in-
C. Sterile sputum cultures fectious infiltrate, resulting in an oxygen saturation above 95%.
D. Oxygen saturation of 98% The disappearance of infectious organisms from post-treatment
E. Elastic skin turgor cultures also indicates resolution of infection. Potassium levels
and elastic skin turgor are not assessment parameters for clinical
infections, including pneumonia.
B. Treating a viral infection
Which are examples of the improper use of antibiotic therapy?
E. Using dosing that results in a superinfection
(Select all that apply.)
A. Using surgical drainage as an adjunct to antibiotic therapy
Common misuses of antibiotics include (1) treatment of a viral
B. Treating a viral infection
infection, which results in exposure of the patient to the risks of
C. Basing treatment on sensitivity reports
the medication without providing any benefits; and (2) improper
D. Treating fever in an immunodeficient patient
dosing (dosing that is too high results in superinfection). The other
E. Using dosing that results in a superinfection
answers are examples of the proper use of antimicrobial therapy.
A. Aortic valve replacement
D. Neutropenia
A nurse should recognize that antibiotic prophylaxis is appropriate
in patients with which medical conditions? (Select all that apply.) Antibiotic prophylaxis is appropriate and effective in certain sit-
A. Aortic valve replacement uations. These include patients who have prosthetic valves and
B. Ruptured appendix are at risk for bacterial endocarditis. The use of antibiotics in
C. Bronchitis "dirty" surgeries, such as those for ruptured organs, is considered
D. Neutropenia treatment, not prophylaxis. Severe neutropenia can put patients
E. Chickenpox at risk for severe infection, and antibiotics can reduce infections
but may encourage fungal invasion. Antibiotics are not prescribed
preventively for bronchitis or chickenpox.
A. Cardiac surgery
B. Recurrent urinary tract infections in women
E. Hysterectomy
Prophylactic use of antibiotics can reduce the incidence of infec-
tion in certain kinds of surgery. Procedures in which prophylactic
The nurse identifies appropriate use of antimicrobials to prevent efficacy has been documented include cardiac surgery, peripheral
infection in which situations? (Select all that apply.) vascular surgery, orthopedic surgery, and surgery on the gas-
A. Cardiac surgery trointestinal (GI) tract (stomach, duodenum, colon, rectum, and
B. Recurrent urinary tract infections in women appendix). Prophylaxis is also beneficial for women undergoing
C. Anemia a hysterectomy or an emergency cesarean section. Severe neu-
D. Treatment of fever of unknown origin tropenia, not anemia puts individuals at high risk of infection. In
E. Hysterectomy young women with recurrent urinary tract infection, prophylaxis
with trimethoprim/sulfamethoxazole may be helpful. Unless the
cause of a fever is a proven infection, antibiotics should not be
used. Fever by itself constitutes a legitimate indication for antibiotic
use only when the fever occurs in a severely immunocompro-
mised person. Because fever may indicate infection and because
infection can be lethal to immunocompromised individuals, these
C. Ability to avoid injuring host cells
An antimicrobial medication that has selective toxicity has which
Selective toxicity refers to an antibiotic that has the ability to injure
characteristic?
only invading microbes, not the host. Conjugation is the process
A. Ability to transfer DNA coding
through which DNA coding for drug resistance is transferred from
B. Ability to suppress bacterial resistance
one bacterium to another. Antibiotics do not suppress bacterial
C. Ability to avoid injuring host cells
resistance, but rather promote the emergence of drug-resistant
D. Ability to act against a specific microbe
microbes. Antibiotics that are narrow spectrum are active against
only a few microbes.
The development of a new infection as a result of the elimination B. Superinfection
of normal flora by an antibiotic is referred to as what?
A. Resistant infection Antibiotic therapy can destroy the normal flora of the body, which
B. Superinfection normally would inhibit the overgrowth of fungi and yeast. When
C. Nosocomial infection the normal flora is decreased, these organisms can overgrow and
D. Allergic reaction cause a new infection, or superinfection.
D. Transfer of DNA coding to another bacteria
A microbe acquires antibiotic resistance by which means? All alterations in structure and function result from changes in the
A. Development of medication resistance in the host microbial genome. The microbe, not the host, becomes medication
B. Over-riding of the minimum bactericidal concentration resistant. Genetic changes in a microbe result either from spon-
C. Incorrect dosing, which contributes to ribosome mutations taneous mutation or from acquisition of DNA from conjugation
D. Transfer of DNA coding to other bacteria with other bacteria. The minimum bacterial concentration (MBC) is
used in testing for drug sensitivity. Incorrect dosing does not lead
to microbe mutations.
B. Competent immune function
The nurse identifies which host factor as the most important when
choosing an antimicrobial drug? Two factors—host defenses and the site of infection—are unique
A. Age to the selection of antibiotics. It is critical for success that an-
B. Competent immune function tibiotics act synergistically with the immune system to subdue
C. Genetic heritage infection. Other host factors, such as age, genetic heritage, and
D. Previous medication reactions previous drug reactions, are the same factors that must be con-
sidered when choosing any other medication.
B. The lowest concentration of an antibiotic needed to reduce the
What is the minimum bactericidal concentration (MBC)?
number of bacterial colonies by 99.9%
A. The lowest concentration of an antibiotic needed to suppress
bacterial growth completely
B. The lowest concentration of an antibiotic needed to reduce the The MBC is the lowest concentration of drug that produces a
99.9% decline in the number of bacterial colonies (indicating bac-
number of bacterial colonies by 99.9%
terial kill). The lowest antibiotic concentration needed to suppress
C. The lowest concentration of an antibiotic needed to produce
bacterial growth or to produce effects and the lowest antibiotic
effects
dose needed to eradicate bacteria are incorrect descriptions of
D. The lowest dose of an antibiotic needed to eradicate bacteria
MBC.
D. Disk diffusion
Which test is the most widely used method for assessing drug
sensitivity? The most widely used method for assessing drug sensitivity
A. Minimum inhibitory concentration (MIC) is the disk diffusion test, also known as the Kirby-Bauer test.
B. Minimum bacterial concentration (MBC) Through diffusion, an antibiotic-containing zone becomes estab-
C. Broth dilution lished around each disk. As the bacteria proliferate, growth is
D. Disk diffusion inhibited around the disks that contain an antibiotic to which the
bacteria are sensitive.
A nurse removes a central line access device once the patient C. Preventing infection
no longer requires intravenous (IV) antibiotics. This action is an
example of which strategy to prevent antimicrobial resistance The CDC's campaign to prevent the development of antimicrobial
established by the Centers for Disease Control and Prevention resistance in hospitals focuses on four approaches: (1) prevent in-
(CDC)? fection, (2) diagnose and treat infection effectively, (3) use antimi-
A. Preventing transmission crobials wisely, and (4) prevent transmission. Expeditious removal
B. Proper diagnosis of invasive devices, such as IV catheters, and restricting these
C. Preventing infection devices to essential use are examples of the CDC's strategy to
D. Prudent antibiotic use prevent infection.
The nurse identifies what as the first step in the Campaign to Pre-
vent Antimicrobial Resistance, established in 2002 by the CDC?
, Antibiotics NCLEX Questions & Rationales 2025 LATEST VERSION
A. Target the pathogen D. Vaccinate
B. Access the experts
C. Isolate the pathogen Although all responses are components of the Campaign to Pre-
D. Vaccinate vent Antimicrobial Resistance, step one is vaccination.
A patient has acquired an infection while in the hospital. The nurse
C. Nosocomial infection
identifies this type of infection as what?
A. Superinfection
Nosocomial infections are acquired by patients while in the hospi-
B. Suprainfection
tal. Superinfection and suprainfection are terms used to describe
C. Nosocomial infection
the emergence of drug resistance.
D. Resistant infection
B. Reduction of fever
C. Sterile sputum cultures
A nurse is assessing the effects of antimicrobial therapy in a pa- D. Oxygen saturation of 98%
tient with pneumonia. The nurse should establish which outcomes
when planning care? (Select all that apply.) Antimicrobial therapy is assessed by monitoring clinical and lab-
A. Potassium level of 4 mEq/dL oratory responses. Clinical indicators of success in a patient with
B. Reduction of fever pneumonia may include afebrile status and resolution of an in-
C. Sterile sputum cultures fectious infiltrate, resulting in an oxygen saturation above 95%.
D. Oxygen saturation of 98% The disappearance of infectious organisms from post-treatment
E. Elastic skin turgor cultures also indicates resolution of infection. Potassium levels
and elastic skin turgor are not assessment parameters for clinical
infections, including pneumonia.
B. Treating a viral infection
Which are examples of the improper use of antibiotic therapy?
E. Using dosing that results in a superinfection
(Select all that apply.)
A. Using surgical drainage as an adjunct to antibiotic therapy
Common misuses of antibiotics include (1) treatment of a viral
B. Treating a viral infection
infection, which results in exposure of the patient to the risks of
C. Basing treatment on sensitivity reports
the medication without providing any benefits; and (2) improper
D. Treating fever in an immunodeficient patient
dosing (dosing that is too high results in superinfection). The other
E. Using dosing that results in a superinfection
answers are examples of the proper use of antimicrobial therapy.
A. Aortic valve replacement
D. Neutropenia
A nurse should recognize that antibiotic prophylaxis is appropriate
in patients with which medical conditions? (Select all that apply.) Antibiotic prophylaxis is appropriate and effective in certain sit-
A. Aortic valve replacement uations. These include patients who have prosthetic valves and
B. Ruptured appendix are at risk for bacterial endocarditis. The use of antibiotics in
C. Bronchitis "dirty" surgeries, such as those for ruptured organs, is considered
D. Neutropenia treatment, not prophylaxis. Severe neutropenia can put patients
E. Chickenpox at risk for severe infection, and antibiotics can reduce infections
but may encourage fungal invasion. Antibiotics are not prescribed
preventively for bronchitis or chickenpox.
A. Cardiac surgery
B. Recurrent urinary tract infections in women
E. Hysterectomy
Prophylactic use of antibiotics can reduce the incidence of infec-
tion in certain kinds of surgery. Procedures in which prophylactic
The nurse identifies appropriate use of antimicrobials to prevent efficacy has been documented include cardiac surgery, peripheral
infection in which situations? (Select all that apply.) vascular surgery, orthopedic surgery, and surgery on the gas-
A. Cardiac surgery trointestinal (GI) tract (stomach, duodenum, colon, rectum, and
B. Recurrent urinary tract infections in women appendix). Prophylaxis is also beneficial for women undergoing
C. Anemia a hysterectomy or an emergency cesarean section. Severe neu-
D. Treatment of fever of unknown origin tropenia, not anemia puts individuals at high risk of infection. In
E. Hysterectomy young women with recurrent urinary tract infection, prophylaxis
with trimethoprim/sulfamethoxazole may be helpful. Unless the
cause of a fever is a proven infection, antibiotics should not be
used. Fever by itself constitutes a legitimate indication for antibiotic
use only when the fever occurs in a severely immunocompro-
mised person. Because fever may indicate infection and because
infection can be lethal to immunocompromised individuals, these
