Anti-infective drugs ( Chapters 83-94) Flashcards
The nurse has been caring for a patient who has been taking antibiotics for 3 weeks. Upon assessing the patient, the nurse notices the individual has developed oral thrush. What describes the etiology of the thrush?
a. Antibiotic resistance
b. Community-acquired infection
c. Nosocomial infection
d. Suprainfection
ANS: D
Oral thrush is a manifestation of a suprainfection. The development of thrush is not a symptom of antibiotic resistance. Oral thrush typically is not a community-acquired infection. The development of thrush is not a nosocomial infection.
The nurse is caring for a patient on a medical-surgical unit who has a fever of unknown origin. The prescriber has ordered a broad-spectrum antibiotic. Which intervention is the priority?
a. Administering the antibiotic immediately
b. Administering antipyretics as soon as possible
c. Delaying administration of the antibiotic until the culture results are available
d. Obtaining all cultures before the antibiotic is administered
ANS: D
It is essential that samples of exudates and body fluids (in this case, blood cultures) be obtained for culture before initiation of treatment. Administration of the antibiotic is important but not more important than obtaining specimens for culture. Antipyretics may be indicated, but the priority is obtaining specimens for culture. Treatment may be initiated before the test results are available.
The nurse is teaching a nursing student about the mechanism by which antimicrobial agents achieve selective toxicity. Which statement by the student indicates a need for further teaching?
a. “Some agents disrupt the bacterial cell wall.”
b. “Some agents act to block the conversion of para-aminobenzoic acid (PABA) to folic acid.”
c. “Some agents cause phagocytosis of bacterial cells.”
d. “Some agents weaken the cell wall, causing cell wall lysis.”
ANS: C
Antimicrobial agents do not cause phagocytosis of bacterial cells. They do disrupt and weaken the bacterial cell wall; because human cells do not have cell walls, antimicrobial agents are not toxic to human cells. Some agents block the conversion of PABA to folic acid; humans do not synthesize folic acid and are not harmed by this process.
A child has received amoxicillin (Amoxil) for three previous ear infections, but a current otitis media episode is not responding to treatment. The nurse caring for this child suspects that resistance to the bacterial agent has occurred by which microbial mechanism?
a. Alteration of drug target molecules
b. Antagonist production
c. Drug inactivation
d. Reduction of drug concentration at the site of action
ANS: B
Drug inactivation can occur when microbes produce drug-metabolizing enzymes. Penicillin-resistant organisms, including many that cause otitis media, produce penicillinase. Alteration of drug target molecules, drug inactivation, and reduction of the drug concentration occur with other antimicrobials.
A nursing student asks a nurse to clarify the differences between the mechanisms of spontaneous mutation and conjugation in acquired resistance of microbes. What will the nurse say?
a. Conjugation results in a gradual increase in resistance.
b. Conjugation results in random changes in the microbe’s DNA.
c. Spontaneous mutation leads to resistance to only one antimicrobial agent.
d. Spontaneous mutation can transfer DNA from one organism to another.
ANS: C
Spontaneous mutation generally confers resistance to only one drug. Conjugation can occur quickly; spontaneous mutation is gradual. Spontaneous mutation is random; conjugation is not. Conjugation can occur with the transfer of DNA from one organism to another.
A patient has a viral sinus infection, and the provider tells the patient that antibiotics will not be prescribed. The patient wants to take an antibiotic and asks the nurse what possible harm could occur by taking an antibiotic. Which response by the nurse is correct?
a. “Antibiotics are mutagenic and can produce changes that cause resistance.”
b. “Even normal flora can develop resistance and transfer this to pathogens.”
c. “Host cells become resistant to antibiotics with repeated use.”
d. “Patients who overuse antibiotics are more likely to have nosocomial infections.”
ANS: B
Antibiotics make conditions favorable for the overgrowth of microbes with acquired resistance. Normal flora, present at all times, can develop resistance and can transfer this resistance to pathogens if they occur. Even when pathogens are not present, antibiotic use can promote resistance in the future. Antibiotics are not mutagenic. Host cells are not affected. Antibiotic use does not increase the risk of nosocomial infection in a particular patient but does increase resistance in resident organisms in a particular hospital.
A patient with recurrent bacterial pneumonia is treated with an antibiotic that has worked previously but is not working to reduce symptoms in a current infection. The nurse caring for this patient understands that this is likely for which reason?
a. The antibiotic altered the genetic makeup of the bacterial strain causing this infection.
b. The antibiotic caused host cells to change and become more susceptible to bacterial effects.
c. The antibiotic caused a mutation of the organism leading to reduced drug sensitivity.
d. The antibiotic destroyed competing organisms that secrete substances toxic to the pathogen.
ANS: D
Antibiotics promote resistance by destroying sensitive organisms and eliminating the toxins they produce, which facilitates survival of resistant organisms. Antibiotics do not alter the genetic makeup of bacteria. The host cells are not affected. Antibiotics are not mutagenic.
A patient has a localized skin infection, which is most likely caused by a gram-positive cocci. Until the culture and sensitivity results are available, the nurse will expect the provider to order a _____-spectrum _____ agent.
a. broad; systemic
b. broad; topical
c. narrow; systemic
d. narrow; topical
ANS: D
When infections are treated before the causative agent has been identified, and after cultures have been obtained, antibiotics may be used based on the knowledge of which microbes are most likely to cause infection at that particular site. Because this is a localized infection, a topical agent is recommended. Unless the infection is very serious, a narrow-spectrum antibiotic is best.
A parent asks a nurse if the provider will prescribe an antibiotic for a child who attends school with several children who have strep throat. The child is complaining of a sore throat and has a fever. What will be the nurse’s response?
a. “Because strep throat is likely, your child should be treated empirically.”
b. “With good hand washing, your child should not get strep throat.”
c. “Your child probably has strep throat, so your provider will order an antibiotic.”
d. “Your child should come to the clinic to have a throat culture done today.”
ANS: D
Whenever possible, the infecting organism should be identified before antibiotics are started, even if there is a strong suspicion that a particular organism is present. The nurse is correct in telling the parent to bring the child to the clinic for a throat culture. Fever and sore throat have other causes, so it is not correct to treat this child empirically, especially because these symptoms are not severe or life threatening. Although good hand washing is always indicated, this child already has symptoms and needs to be evaluated. Antibiotics should not be started until indicated by cultures
An older adult patient with chronic obstructive pulmonary disease (COPD) develops bronchitis. The patient has a temperature of 39.5° C. The nurse will expect the provider to:
a. obtain a sputum culture and wait for the results before prescribing an antibiotic.
b. order empiric antibiotics while waiting for sputum culture results.
c. treat symptomatically, because antibiotics are usually ineffective against bronchitis.
d. treat the patient with more than one antibiotic without obtaining cultures.
ANS: B
Patients with severe infections should be treated while culture results are pending. If a patient has a severe infection or is at risk of serious sequelae if treatment is not begun immediately, it is not correct to wait for culture results before beginning treatment. Until a bacterial infection is ruled out, treating symptomatically is not indicated. Treating without obtaining cultures is not recommended.
Which methods have been identified for preventing antimicrobial resistance? (Select all that apply.)
a. Administering influenza vaccine
b. Stopping antibiotic therapy as soon as possible when treating infection
c. Treating bacterial colonization in asymptomatic patients
d. Using narrow-spectrum antibiotics when possible
e. Using national data to determine antimicrobial drug selection
ANS: A, B, D
Vaccines help prevent disease and thus reduce the need to use antimicrobial drugs. Discontinuing antibiotic therapy as soon as possible, such as when an infection has been fully treated or when an infection is unlikely, helps reduce exposure of normal flora and other microbes to antimicrobials. Narrow-spectrum antibiotics target the pathogen and are less likely to act against other microbes. It is not correct to treat bacterial colonization when patients are asymptomatic. Local data give clearer information on local trends in susceptibility and resistance and thus are more likely to guide antimicrobial drug selection correctly.
Which are benefits of using a combination of two or more antibiotics? (Select all that apply.)
a. Reduced cost
b. Reduced risk of suprainfection
c. Reduced toxicity
d. Reduced resistance
e. Reduced risk in severe infection
ANS: C, D, E
In some situations, an antibiotic combination can reduce toxicity, because the dosage of a more toxic agent can be reduced. Drug combinations can be used to suppress the emergence of resistant bacteria in the treatment of tuberculosis. With a severe infection, a combination of antibiotics is useful until culture results are known to ensure that all possible sources of infection are treated. Using multiple antibiotics is more costly and poses a greater risk of suprainfection.
The nurse is teaching a pharmacology refresher course to a group of nurses. A student asks what host factors affect the choice of agents in antimicrobial therapy. The nurse will tell the students that such host factors include what? (Select all that apply.)
a. Age
b. Gender
c. Immune system status
d. Infection site
e. Weight
ANS: A, C, D
Host factors, such as the patient’s age, immune status, and the site of the infection, affect the choice of antimicrobial therapy used to treat an infection. Gender and weight do not affect the choice of antimicrobial but may affect the dose and route of administration.
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.
ANS: A
Gentamicin should never be administered concurrently with penicillin, because they will interact, and the penicillin may inactivate the aminoglycoside. All the other options show concurrent administration.
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?
a. Make sure to administer the drugs at different times using different IV tubing.
b. Suggest giving larger doses of piperacillin and discontinuing the amikacin.
c. Suggest that a fixed-dose combination of piperacillin and tazobactam (Zosyn) be used.
d. Watch the patient closely for allergic reactions, because this risk is increased with this combination.
ANS: A
When penicillins are present in high concentrations, they interact with aminoglycosides and inactivate the aminoglycoside; therefore, these two drugs should never be mixed in the same IV solution. The drugs should be given at different times with different tubing. In the treatment of Pseudomonas infections, extended-spectrum penicillins, such as piperacillin, usually are given in conjunction with an antipseudomonal aminoglycoside, such as amikacin; therefore, suggesting a larger dose of piperacillin and discontinuation of the amikacin is incorrect. Zosyn is not recommended. The risk of allergic reactions does not increase with this combination of drugs.
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:
a. disinhibit transpeptidases.
b. disrupt bacterial cell wall synthesis.
c. inhibit autolysins.
d. inhibit host cell wall function.
ANS: B
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.
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.”
ANS: D
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.
A child with an ear infection is not responding to treatment with amoxicillin (Amoxil). The nurse will expect the provider to order:
a. amoxicillin–clavulanic acid (Augmentin).
b. ampicillin.
c. nafcillin.
d. penicillin G (Benzylpenicillin).
ANS: A
Beta-lactamase inhibitors are drugs that inhibit bacterial beta-lactamases. These drugs are always given in combination with a penicillinase-sensitive penicillin. Augmentin contains amoxicillin and clavulanic acid and is often used when patients fail to respond to amoxicillin alone. Ampicillin is similar to amoxicillin, but amoxicillin is preferred and, if drug resistance occurs, ampicillin is equally ineffective. Pharmaceutical chemists have developed a group of penicillins that are resistant to inactivation by beta-lactamases (e.g., nafcillin), but these drugs are indicated only for penicillinase-producing strains of staphylococci. Penicillin G would be as ineffective as amoxicillin if beta-lactamase is present.
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.
ANS: C
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.
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.
ANS: C
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.
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.
ANS: A
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.
A patient has an infection caused by Streptococcus pyogenes. The prescriber has ordered dicloxacillin PO. What will the nurse do?
a. Administer the medication as ordered.
b. Contact the provider to suggest giving the drug IV.
c. Question the need for a penicillinase-resistant penicillin.
d. Suggest ordering vancomycin to treat this infection.
ANS: C
Penicillinase-resistant penicillins have been developed for use against penicillinase-producing strains of staphylococci. These drugs have a very narrow antimicrobial spectrum and should be used only for such infections. S. pyogenes can be treated with penicillin G. The nurse should question the order. It is incorrect to contact the provider to ask for IV dosing. This infection can be treated with penicillin G and not with vancomycin.
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?
a. Amoxicillin is a broader spectrum antibiotic than ampicillin.
b. Amoxicillin is not inactivated by beta-lactamases.
c. Ampicillin is associated with more allergic reactions.
d. Ampicillin is not as acid stable as amoxicillin.
ANS: D
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.
A patient with an infection caused by Pseudomonas 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.
ANS: C
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.
A nurse is discussing methicillin-resistant Staphylococcus aureus (MRSA) with a group of nursing students. Which statement by a student correctly identifies the basis for MRSA resistance?
a. “MRSA bacteria have developed PBPs with a low affinity for penicillins.”
b. “MRSA bacteria produce penicillinases that render penicillin ineffective.”
c. “MRSA occurs because of host resistance to penicillins.”
d. “MRSA strains replicate faster than other Staphylococcus aureus strains.”
ANS: A
MRSA strains have a unique mechanism of resistance, which is the production of PBPs with a low affinity for penicillins and all other beta-lactam antibiotics. MRSA resistance is not related to beta-lactamase production. MRSA resistance refers to bacterial and not host resistance. The resistance of MRSA strains is not related to speed of replication.
Which organisms can be treated with penicillin G (Benzylpenicillin)? (Select all that apply.)
a. Methicillin-resistant Staphylococcus aureus
b. Neisseria meningitidis
c. Pseudomonas aeruginosa
d. Streptococcus pyogenes
e. Treponema pallidum
ANS: B, D, E
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.
A nursing student wants to know the differences between hospital-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) and community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). Which statements about CA-MRSA are true? (Select all that apply.)
a. Twenty percent 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.
ANS: A, B, C
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 Staphylococcus 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.
A patient who is receiving a final dose of intravenous (IV) cephalosporin begins to complain of pain and irritation at the infusion site. The nurse observes signs of redness at the IV insertion site and along the vein. What is the nurse’s priority action?
a. Apply warm packs to the arm, and infuse the medication at a slower rate.
b. Continue the infusion while elevating the arm.
c. Select an alternate intravenous site and administer the infusion more slowly.
d. Request central venous access.
ANS: C
These signs indicate thrombophlebitis. The nurse should select an alternative IV site and administer the infusion more slowly. The IV should not be continued in the same site, because necrosis may occur. A central line would be indicated only for long-term administration of antibiotics.
Which cephalosporin may be used to treat meningitis?
a. Cefaclor
b. Cefazolin
c. Cefoxitin
d. Cefotaxime
ANS: D
Cefotaxime has increased ability to reach the cerebrospinal fluid (CSF) and to treat meningitis. Cefaclor, cefazolin, and cefoxitin do not reach effective concentrations in the CSF.
A patient complains of burning on urination and increased frequency. The patient has a history of frequent urinary tract infections (UTIs) and is going out of town in 2 days. To treat the infection quickly, the nurse would expect the healthcare provider to order:
a. aztreonam (Azactam).
b. fosfomycin (Monurol).
c. trimethoprim/sulfamethoxazole (Bactrim).
d. vancomycin (Vancocin).
ANS: B
Fosfomycin has been approved for single-dose therapy of UTIs. Vancomycin and aztreonam are not indicated for UTIs. Bactrim is indicated for UTIs, but administration of a single dose is not therapeutic
A nurse is teaching a nursing student what is meant by “generations” of cephalosporins. Which statement by the student indicates understanding of the teaching?
a. “Cephalosporins are assigned to generations based on their relative costs to administer.”
b. “Cephalosporins have increased activity against gram-negative bacteria with each generation.”
c. “First-generation cephalosporins have better penetration of the cerebrospinal fluid.”
d. “Later generations of cephalosporins have lower resistance to destruction by beta-lactamases.”
ANS: B
With each progression from first-generation agents to fourth-generation agents, the cephalosporins show increased activity against gram-negative organisms, increased resistance to destruction by beta-lactamases, and increased ability to reach the CSF. Cost is not a definitive factor. First-generation drugs have less penetration of the CSF. Resistance to destruction by beta-lactamases increases with increasing generations.
A provider has ordered ceftriaxone 4 gm once daily for a patient with renal impairment. What will the nurse do?
a. Administer the medication as prescribed.
b. Contact the provider to ask about giving the drug in divided doses.
c. Discuss increasing the interval between doses with the provider.
d. Discuss reducing the dose with the provider.
ANS: A
Unlike other cephalosporins, ceftriaxone is eliminated largely by the liver, so dosage reduction is unnecessary in patients with renal impairment. Giving the drug in divided doses, increasing the interval between doses, and reducing the dose are not necessary.
A prescriber has ordered cefoxitin for a patient who has an infection caused by a gram-negative bacteria. The nurse taking the medication history learns that the patient experienced a maculopapular rash when taking amoxicillin (Amoxil) several years earlier. What will the nurse do?
a. Administer the cefoxitin and observe for any side effects.
b. Give the cefoxitin and have epinephrine and respiratory support available.
c. Request an order for a different, nonpenicillin, noncephalosporin antibiotic.
d. Request an order to administer a skin test before giving the cefoxitin.
ANS: A Because of structural similarities between penicillins (PCNs) and cephalosporins, a few patients allergic to one drug type will be allergic to the other drug type, although this is rare. For patients with mild PCN allergy, such as rash, cephalosporins can be used with minimal concern, so it is correct to administer the drug and monitor for side effects. It is unnecessary to prepare for anaphylaxis, to give another class of drug, or to administer a skin test.
A patient will be discharged home to complete treatment with intravenous cefotetan with the assistance of a home nurse. The home care nurse will include which instruction when teaching the patient about this drug treatment?
a. Abstain from alcohol consumption during therapy.
b. Avoid dairy products while taking this drug.
c. Take an antihistamine if a rash occurs.
d. Use nonsteroidal anti-inflammatory drugs (NSAIDs), not acetaminophen, for pain.
ANS: A
Four cephalosporins, including cefotetan, can induce a state of alcohol intolerance and cause a disulfiram-like reaction when alcohol is consumed; therefore, patients should be advised to avoid alcohol. It is not necessary to avoid dairy products. Patients who experience a rash should report this to their provider. Cefotetan can also promote bleeding, so drugs that inhibit platelet aggregation should be avoided.
The nurse is caring for a patient who is receiving vancomycin (Vancocin). The nurse notes that the patient is experiencing flushing, rash, pruritus, and urticaria. The patient’s heart rate is 120 beats per minute, and the blood pressure is 92/57 mm Hg. The nurse understands that these findings are consistent with:
a. allergic reaction.
b. red man syndrome.
c. rhabdomyolysis.
d. Stevens-Johnson syndrome.
ANS: B
Rapid infusion of vancomycin can cause flushing, rash, pruritus, urticaria, tachycardia, and hypotension, a collection of symptoms known as red man syndrome. Rhabdomyolysis is not associated with the administration of vancomycin. The patient’s symptoms may seem to indicate an allergic reaction, but this is specifically red man syndrome. The symptoms are not those of Stevens-Johnson syndrome, which manifests as blisters or sores (or both) on the lips and mucous membranes after exposure to the sun.
A patient is to undergo orthopedic surgery, and the prescriber will order a cephalosporin to be given preoperatively as prophylaxis against infection. The nurse expects the provider to order which cephalosporin?
a. First-generation cephalosporin
b. Second-generation cephalosporin
c. Third-generation cephalosporin
d. Fourth-generation cephalosporin
ANS: A
First-generation cephalosporins are widely used for prophylaxis against infection in surgical patients, because they are as effective, less expensive, and have a narrower antimicrobial spectrum than second-, third-, and fourth-generation cephalosporins.
A patient receiving a cephalosporin develops a secondary intestinal infection caused by Clostridium difficile. What is an appropriate treatment for this patient?
a. Adding an antibiotic, such as vancomycin (Vancocin), to the patient’s regimen
b. Discontinuing the cephalosporin and beginning metronidazole (Flagyl)
c. Discontinuing all antibiotics and providing fluid replacement
d. Increasing the dose of the cephalosporin and providing isolation measures
ANS: B
Patients who develop C. difficile infection (CDI) as a result of taking cephalosporins or other antibiotics need to stop taking the antibiotic in question and begin taking either metronidazole or vancomycin. Adding one of these antibiotics without withdrawing the cephalosporin is not indicated. CDI must be treated with an appropriate antibiotic, so stopping all antibiotics is incorrect. Increasing the cephalosporin dose would only aggravate the CDI.
Besides the cost of administering a given drug, which are considerations when a provider selects a cephalosporin to treat an infection? (Select all that apply.)
a. Adverse effects
b. Antimicrobial spectrum
c. Brand name
d. Manufacturer
e. Pharmacokinetics
ANS: A, B, E
Cephalosporins tend to be more alike than different, but some differences make some preferable to others. Adverse effects, antimicrobial spectrum, and drug pharmacokinetics affect a prescriber’s decision to select one drug over another. The agent’s brand name and manufacturer should not have anything to do with drug selection.
A nurse is providing education about tetracycline (Sumycin). Which statement by the patient best demonstrates understanding of the administration of this medication?
a. “I should not take this medication with milk or other dairy products.”
b. “I should not worry if I experience an acnelike rash with this medication.”
c. “I should take an antacid, such as Tums, if I experience gastrointestinal distress.”
d. “I should take this antibiotic with a calcium supplement to improve absorption.”
ANS: A
The patient should avoid taking the medication with dairy products to help prevent chelation. An acnelike reaction would indicate an allergic response. Taking the medication with calcium-containing antacids or supplements should be avoided, because this also leads to chelation.
A pregnant adolescent patient asks the nurse whether she should continue to take her prescription for tetracycline (Sumycin) to clear up her acne. Which response by the nurse is correct?
a. “Tetracycline can be harmful to the baby’s teeth and should be avoided.”
b. “Tetracycline is safe to take during pregnancy.”
c. “Tetracycline may cause allergic reactions in pregnant women.”
d. “Tetracycline will prevent asymptomatic urinary tract infections.”
ANS: A
Tetracyclines can cause discoloration of deciduous and permanent teeth. Tooth discoloration can be prevented if the drugs are not taken by pregnant women or by children under 8 years of age. Tetracycline is not appropriate for a pregnant patient. Pregnancy does not precipitate an allergic response to tetracycline. Tetracycline should not be used to prevent urinary tract infections (UTIs), especially in pregnant women.
A patient recently began receiving clindamycin (Cleocin) to treat an infection. After 8 days of treatment, the patient reports having 10 to 15 watery stools per day. What will the nurse tell this patient?
a. The provider may increase the clindamycin dose to treat this infection.
b. This is a known side effect of clindamycin, and the patient should consume extra fluids.
c. The patient should stop taking the clindamycin now and contact the provider immediately.
d. The patient should try taking Lomotil or a bulk laxative to minimize the diarrheal symptoms.
ANS: C
Clostridium difficile–associated diarrhea (CDAD) is the most severe toxicity of clindamycin; if severe diarrhea occurs, the patient should be told to stop taking clindamycin immediately and to contact the provider so that treatment with vancomycin or metronidazole can be initiated. Increasing the dose of clindamycin will not treat this infection. Consuming extra fluids while still taking the clindamycin is not correct, because CDAD can be fatal if not treated. Taking Lomotil or bulk laxatives only slows the transit of the stools and does not treat the cause.
A patient is diagnosed with periodontal disease, and the provider orders oral doxycycline (Periostat). The patient asks the purpose of the drug. What is the nurse’s response?
a. “It is used because of its anti-inflammatory effects.”
b. “It inhibits collagenase to protect connective tissue in the gums.”
c. “It reduces bleeding and the pocket depth of oral lesions.”
d. “It suppresses bacterial growth in the oral mucosa.”
ANS: B
Two tetracyclines are used for periodontal disease. Doxycycline inhibits collagenase, which destroys connective tissue in the gums. It is not used for anti-inflammatory effects. Minocycline is used to reduce bleeding and pocket depth and to inhibit bacterial growth.
To prevent yellow or brown discoloration of teeth in children, tetracyclines should not be given:
a. to children once the permanent teeth have developed.
b. to patients taking calcium supplements.
c. to pregnant patients after the fourth month of gestation.
d. with dairy products or antacids.
ANS: C
Tetracyclines bind to calcium in developing teeth, resulting in yellow or brown discoloration. They should not be given to pregnant women after the fourth month of gestation, because they will cause staining of deciduous teeth in the fetus. In children, discoloration occurs when tetracyclines are given between the ages of 4 and 8 years, because this is when permanent teeth are developing. Tetracycline binds with calcium, so absorption is diminished when the drug is given with calcium supplements, dairy products, or calcium-containing antacids; however, this does not affect tooth development.
A patient is to begin taking doxycycline to treat a rickettsial infection. Which statement by the patient indicates a need for teaching about this drug?
a. “I should consult my provider before using laxatives or antacids while taking this drug.”
b. “I should not take a calcium supplement or consume dairy products with this drug.”
c. “I should take this drug with food to ensure more complete absorption.”
d. “If I get diarrhea, I should stop taking the drug and let my provider know immediately.”
ANS: C
Absorption of tetracyclines is reduced in the presence of food. The tetracyclines form insoluble chelates with calcium, iron, magnesium, aluminum, and zinc, so patients should not take tetracyclines with dairy products, calcium supplements, or drugs containing these minerals. Patients who experience diarrhea should stop taking the drug and notify the provider so they can be tested for C. difficile infection.
A patient who is taking doxycycline for a serious infection contacts the nurse to report anal itching. The nurse will contact the provider to discuss:
a. adding an antihistamine to the patient’s drug regimen.
b. ordering liver function tests to test for hepatotoxicity.
c. prescribing an antifungal drug to treat a suprainfection.
d. testing the patient for a C. difficile secondary infection.
ANS: C
A suprainfection occurs secondary to suppression of drug-sensitive organisms. Overgrowth with fungi, especially Candida albicans, is common and may occur in the mouth, pharynx, vagina, and bowel. Anal itching is a sign of such an infection, not a sign of hepatotoxicity. Antihistamines will not treat the cause. C. difficile is characterized by profuse, watery diarrhea.
A hospitalized patient who is taking demeclocycline (Declomycin) reports increased urination, fatigue, and thirst. What will the nurse do?
a. Contact the provider to report potential toxic side effects.
b. Notify the provider to discuss changing the medication to doxycycline.
c. Perform bedside glucometer testing to evaluate the serum glucose level.
d. Provide extra fluids and reassure the patient that these are expected side effects.
ANS: D
Demeclocycline stimulates urine flow and sometimes is used to treat patients with syndrome of inappropriate antidiuretic hormone secretion (SIADH). The patient should be reassured that increased urination, fatigue, and thirst are known side effects of demeclocycline. It is not correct to notify the provider of toxic side effects or to request another tetracycline. Glucometer testing is not necessary, because the increased urination is not related to an elevated blood glucose level.
A 6-week-old infant who has not yet received immunizations develops a severe cough. While awaiting nasopharyngeal culture results, the nurse will expect to administer which antibiotic?
a. Clindamycin (Cleocin)
b. Doxycycline (Vibramycin)
c. Erythromycin ethylsuccinate
d. Penicillin G
ANS: C
Erythromycin is the drug of first choice for infections caused by Bordetella pertussis, the causative agent of whooping cough. Infants who have not received their first set of immunizations are at increased risk of pertussis. Clindamycin, doxycycline, and penicillin are not recommended.
A child with an upper respiratory infection caused by B. pertussis is receiving erythromycin ethylsuccinate. After 2 days of treatment, the parent asks the nurse why the child’s symptoms have not improved. Which response by the nurse is correct?
a. “Erythromycin eliminates the bacteria that causes the infection, but not the toxin that causes the symptoms.”
b. “We may need to add penicillin or another antibiotic to increase the antimicrobial spectrum.”
c. “We will need to review the culture sensitivity information to see whether a different antibiotic is indicated.”
d. “Your child may have developed a suprainfection that we need to culture and treat.”
ANS: A
Erythromycin is the drug of first choice for treating pertussis infections. Because symptoms are caused by a bacterial toxin and not by the bacteria itself, the drug eliminates the bacteria but does little to alter the course of the disease. It is given to lower infectivity. It is not necessary to add another antibiotic, review the sensitivity information, or look for a suprainfection.
A patient is taking erythromycin ethylsuccinate for a chlamydial infection and develops vaginal candidiasis. The prescriber orders ketoconazole to treat the suprainfection. What will the nurse do?
a. Administer the erythromycin and the ketoconazole as ordered.
b. Contact the provider to discuss changing to a different antifungal medication.
c. Contact the provider to discuss increasing the dose of erythromycin.
d. Contact the provider to suggest using erythromycin stearate.
ANS: B
Erythromycin can prolong the QT interval when present in large concentrations. When erythromycin is combined with a CYP3A4 inhibitor, such as ketoconazole, the risk of sudden cardiac death increases fivefold. The nurse should discuss changing the antifungal medication to one that is not a CYP3A4 inhibitor. It is not correct to give the ketoconazole without questioning the order. Increasing the dose of erythromycin would increase the risk of QT prolongation. Changing to a different preparation of erythromycin would not alter the risk.
A nurse is providing teaching for a patient who will begin taking clarithromycin ER (Biaxin XL) to treat an Helicobacter pylori infection. Which statement by the patient indicates understanding of the teaching?
a. “I may experience distorted taste when taking this medication.”
b. “I should take 1 tablet twice daily for 10 days.”
c. “I should take this medication on an empty stomach.”
d. “This medication does not interact with other drugs.”
ANS: A
Clarithromycin is available in an extended-relief preparation as Biaxin XL. Biaxin can cause distortion of taste, so patients should be warned of this side effect. Biaxin XL should be taken once and not twice daily. Biaxin should be taken with food. Biaxin interacts with other drugs by inhibiting hepatic metabolism of those drugs.
A patient received 500 mg of azithromycin (Zithromax) at 0800 as a first dose. What are the usual amount and time of the second dose of azithromycin?
a. 250 mg at 2000 the same day
b. 500 mg at 2000 the same day
c. 250 mg at 0800 the next day
d. 500 mg at 0800 the next day
ANS: C
Azithromycin generally is given as 500 mg on the first day and then 250 mg/day for the next 4 days, so the second dose would be 24 hours after the first dose.
Which side effect of clindamycin (Cleocin) causes the most concern and may warrant discontinuation of the drug?
a. Diarrhea
b. Headache
c. Nausea
d. Vomiting
ANS: A
CDAD is a serious, sometimes fatal suprainfection associated with clindamycin. Patients with diarrhea should notify their prescriber immediately and discontinue the drug until this condition has been ruled out. Headache, nausea, and vomiting do not warrant discontinuation of the drug and are not associated with severe side effects.
A patient develops CDAD. Which antibiotic is recommended for treating this infection?
a. Chloramphenicol
b. Clindamycin (Cleocin)
c. Linezolid (Zyvox)
d. Vancomycin
ANS: D
Vancomycin and metronidazole are the drugs of choice for treating CDAD.
A patient who has been taking linezolid (Zyvox) for 6 months develops vision problems. What will the nurse do?
a. Reassure the patient that this is a harmless side effect of this drug.
b. Tell the patient that blindness is likely to occur with this drug.
c. Tell the patient that this symptom is reversible when the drug is discontinued.
d. Tell the patient to take tyramine supplements to minimize this effect.
ANS: C
Linezolid is associated with neuropathy, including optic neuropathy. This is a reversible effect that will stop when the drug is withdrawn. Reassuring the patient that this is a harmless side effect is not correct. It is not an indication that blindness will occur. Tyramine supplements are not indicated.
A nurse is teaching a nursing student about dalfopristin/quinupristin (Synercid). Which statement by the student indicates an understanding of the teaching?
a. “Patients should stop taking the drug if they experience joint and muscle pain.”
b. “Patients taking this drug should have blood tests performed frequently.”
c. “Patients who are allergic to penicillin should not take this drug.”
d. “This drug will be administered intravenously over a 30- to 60-minute period.”
ANS: B
Patients taking dalfopristin/quinupristin should have blood levels measured twice the first week and then weekly thereafter to assess for hepatotoxicity. Joint and muscle pain are not an indication for withdrawing the drug. There is no cross-sensitivity to penicillin. The drug is given intravenously over a period of at least 1 hour.
A child has been receiving chloramphenicol for a Neisseria meningitidis central nervous system (CNS) infection. The nurse administers the dose and subsequently notes that the child has vomited and appears dusky and gray in color. The child’s abdomen is distended. What will the nurse do?
a. Contact the provider for an order to obtain a chloramphenicol level.
b. Notify the provider that the child’s meningitis is worsening.
c. Recognize this as initial signs of a C. difficile infection.
d. Stop the infusion immediately and notify the provider.
ANS: D
Gray syndrome is a potentially fatal toxicity associated with chloramphenicol use. When symptoms occur, the drug should be stopped immediately. Lower chloramphenicol levels may prevent gray syndrome, but lowering the dose will not stop symptoms once they have appeared. These are not signs of worsening meningitis or a C. difficile infection.
Tetracyclines are considered first-line drugs for which disorder(s)? (Select all that apply.)
a. Chlamydia trachomatis cervicitis
b. Clostridium difficile diarrhea
c. Lyme disease
d. Methicillin-resistant Staphylococcal aureus skin infections
e. Typhus fever
ANS: A, C, E
Tetracyclines are drugs of first choice for rickettsial diseases, infections caused by C. trachomatis, brucellosis, cholera, Mycoplasma pneumonia, Lyme disease, anthrax, and gastric infections caused by H. pylori. They are not first-line drugs for CDAD or MRSA skin infections.
Which infection(s) may be treated with linezolid (Zyvox)? (Select all that apply.)
a. Community-acquired pneumonia (CAP) that is penicillin sensitive
b. Nosocomial pneumonia caused by methicillin-sensitive Staphylococcus aureus (MSSA)
c. Pneumonias caused by Mycoplasma avium
d. Superficial methicillin-resistant Staphylococcal aureus skin infections (MRSA)
e. Vancomycin-resistant infections
ANS: A, B, E
Linezolid is indicated for CAP caused by PCN-sensitive strains of Streptococcus pneumoniae, nosocomial pneumonia caused by MSSA and MRSA, and vancomycin-resistant enterococcal (VRE) infections. It is not recommended for M. avium infections or for superficial skin infections caused by MRSA.
A patient has a Pseudomonas aeruginosa infection that is sensitive to aminoglycosides, and the prescriber orders gentamicin. The patient tells the nurse that a friend received amikacin (Amikin) for a similar infection and wonders why amikacin was not ordered. What will the nurse tell the patient?
a. “Amikacin is given when infectious agents are resistant to other aminoglycosides.”
b. “Amikacin is more vulnerable to inactivation by bacterial enzymes.”
c. “Amikacin is a narrow-spectrum drug and will probably not work for this infection.”
d. “Gentamicin is less toxic to the ears and the kidneys.”
ANS: A
Resistance to amikacin is uncommon at this point; to minimize the emergence of amikacin-resistant bacteria, this drug is reserved for infections in which resistance to other aminoglycosides has developed. Amikacin is the least susceptible to inactivation by bacterial enzymes. Amikacin is a broad-spectrum antibiotic. All aminoglycosides are ototoxic and nephrotoxic.
A patient is diagnosed with an infection caused by Staphylococcus aureus, and the prescriber orders intravenous gentamicin and penicillin (PCN). Both drugs will be given twice daily. What will the nurse do?
a. Administer gentamicin, flush the line, and then give the penicillin.
b. Give the gentamicin intravenously and the penicillin intramuscularly.
c. Infuse the gentamicin and the penicillin together to prevent fluid overload.
d. Request an order to change the penicillin to vancomycin.
ANS: A
Gentamicin should not be infused with penicillins in the same solution, because PCN inactivates gentamicin; therefore, the nurse should give one first, flush the line, and then give the other. The nurse cannot give a drug IM when it is ordered IV without an order from the prescriber. These two drugs should not be infused in the same solution. There is no indication for changing the PCN to vancomycin; that should be done for serious infections.
A nurse is reviewing the culture results of a patient receiving an aminoglycoside. The report reveals an anaerobic organism as the cause of infection. What will the nurse do?
a. Contact the provider to discuss an increased risk of aminoglycoside toxicity.
b. Continue giving the aminoglycoside as ordered.
c. Request an order for a different class of antibiotic.
d. Suggest adding a penicillin to the patient’s drug regimen.
ANS: C Aminoglycosides are not effective against anaerobic microbes, so another class of antibiotics is indicated. There is no associated increase in aminoglycoside toxicity with anaerobic infection. The aminoglycoside will not be effective, so continuing to administer this drug is not indicated. Adding another antibiotic is not useful, because the aminoglycoside is not necessary.
A patient is diagnosed with a lung infection caused by P. aeruginosa. The culture and sensitivity report shows sensitivity to all aminoglycosides. The nurse knows that the rate of resistance to gentamicin is common in this hospital. The nurse will expect the provider to order which medication?
a. Amikacin (Amikin)
b. Gentamicin
c. Paromomycin
d. Tobramycin
ANS: A
When resistance to gentamicin and tobramycin is common, amikacin is the drug of choice for initial treatment of aminoglycoside-sensitive infections. Gentamicin would not be indicated, because resistance is more likely to develop. Paromomycin is used only for local effects within the intestine and is given orally. Tobramycin is not indicated, because organisms can more readily develop resistance.
A nurse preparing to administer intravenous gentamicin to a patient notes that the dose is half the usual dose for an adult. The nurse suspects that this is because this patient has a history of:
a. antibiotic resistance.
b. interpatient variation.
c. liver disease.
d. renal disease.
ANS: D
The aminoglycosides are eliminated primarily by the kidneys, so in patients with renal disease, doses should be reduced or the dosing interval should be increased to prevent toxicity. Patients with antibiotic resistance would be given amikacin. Interpatient variation may occur but cannot be known without knowing current drug levels. Aminoglycosides are not metabolized by the liver, so liver disease would not affect drug levels.
A patient is admitted to the unit for treatment for an infection. The patient receives IV amikacin (Amikin) twice a day. When planning for obtaining a peak aminoglycoside level, when should the nurse see that the blood is drawn?
a. 30 minutes after the IV infusion is complete
b. 1 hour after the IV infusion is complete
c. 1 hour before administration of the IV infusion
d. A peak level is not indicated with twice-daily dosing.
ANS: A
When divided daily doses are used, blood samples for measurement of peak levels are drawn 1 hour after IM injection and 30 minutes after completion of an IV infusion. This medication is administered IV, so blood draws must follow 30 minutes after infusion to obtain peak levels. Measurement of peak levels is unnecessary only when a single daily dose is used.
A patient who has been receiving intravenous gentamicin for several days reports having had a headache for 2 days. The nurse will request an order to:
a. obtain a gentamicin trough before the next dose is given.
b. give an analgesic to control headache discomfort.
c. reduce the dose of the gentamicin to minimize side effects.
d. obtain renal function tests to evaluate for potential nephrotoxicity.
ANS: A
A headache may be a sign of developing ototoxicity, so a gentamicin trough should be obtained before the next dose is given. Analgesics are not indicated until a serious cause of the headache has been ruled out. Reducing the dose without first knowing the level would not be indicated. A headache is an early sign of ototoxicity, not nephrotoxicity.
A patient who has been taking gentamicin for 5 days reports a headache and dizziness. What will the nurse do?
a. Request an order for a gentamicin peak level.
b. Suspect ototoxicity and notify the prescriber.
c. Tell the patient to ask for help with ambulation.
d. Tell the patient to report any tinnitus.
ANS: B
Headache and dizziness are signs of ototoxicity, and the prescriber should be notified. A peak level is not indicated; it is more important to know the trough level. Telling the patient to ask for help with ambulation and to report tinnitus should both be done but are not the priority nursing action.
A patient who takes the loop diuretic ethacrynic acid is given intravenous gentamicin for an infection. After several days of treatment with gentamicin, the nurse reviews the patient’s most recent laboratory results and notes a gentamicin trough of 2.1 mcg/mL and normal blood urea nitrogen (BUN) and serum creatinine levels. The nurse will question the patient about:
a. gastrointestinal (GI) symptoms.
b. headache, dizziness, or vertigo.
c. presence of rash.
d. urine output.
ANS: B
Ethacrynic acid has ototoxic properties, and patients who take this drug with an aminoglycoside have an increased risk of ototoxicity, especially when trough levels of the aminoglycoside are elevated. A trough level of 2.1 mcg/mL is above normal limits for gentamicin, so this patient should be asked about early signs of ototoxicity. There is no indication to evaluate for GI symptoms, rash, or urine output.
A patient is receiving an intraperitoneal aminoglycoside during surgery. To prevent a serious side effect of this drug, the nurse expects to administer which agent?
a. Amphotericin B
b. Calcium gluconate
c. Neuromuscular blocker
d. Vancomycin
ANS: B
Aminoglycosides can inhibit neuromuscular transmission, especially during intraperitoneal or intrapleural instillation, and this risk is increased when neuromuscular blocking agents and general anesthetics are given. Calcium can reverse neuromuscular blockade. Amphotericin B, additional neuromuscular blockers, and vancomycin are not indicated.
A patient shows signs and symptoms of conjunctivitis. Which aminoglycoside would the nurse expect to be ordered?
a. Amikacin (Amikin)
b. Kanamycin (Kantrex)
c. Neomycin (Neomycin)
d. Paromomycin (Humatin)
ANS: C
Neomycin is used for topical treatment of infections of the eye, ear, and skin. Amikacin, kanamycin, and paromomycin are not topical treatments and are not indicated for eye infections.
A nurse is explaining to nursing students why a cephalosporin is used in conjunction with an aminoglycoside for a patient with an infection. Which statement by a student indicates understanding of the teaching?
a. “Cephalosporins enhance the actions of aminoglycosides by weakening bacterial cell walls.”
b. “Cephalosporins prevent neuromuscular blockade associated with aminoglycosides.”
c. “Cephalosporins prolong the postantibiotic effects of the aminoglycosides so doses can be decreased.”
d. “Cephalosporins reduce bacterial resistance to aminoglycosides.”
ANS: A
Cephalosporins, penicillins, and vancomycin can be used in conjunction with aminoglycosides; these drugs weaken the bacterial cell wall and enhance the bactericidal actions of aminoglycosides. Cephalosporins do not prevent neuromuscular blockade. They do not prolong the postantibiotic effects of aminoglycosides. They do not affect bacterial resistance.
A patient who is taking gentamicin and a cephalosporin for a postoperative infection requests medication for mild postsurgical pain. The nurse will expect to administer which of the following medications?
a. Acetaminophen
b. Aspirin
c. Ibuprofen
d. Morphine
ANS: A
Gentamicin and cephalosporins are both nephrotoxic. This patient should avoid taking other potentially nephrotoxic drugs. Acetaminophen is not nephrotoxic and may be given for mild pain. Aspirin and ibuprofen are both nephrotoxic. Morphine is not nephrotoxic but is not indicated for mild pain.
