Chapter 19: DT With Aminoglycosides and Fluoroquinolones
A patient is diagnosed with an infection attributable to the gram-negative microorganism Pseudomonas. Which of the following anti-infective agents is most reliable in treating this microorganism? A) Aminoglycoside B) Antifungal C) Aminopenicillin D) GABA analog
Ans: A Feedback: Aminoglycosides are used to treat infections caused by gram-negative microorganisms, such as Pseudomonas. Antifungal and aminopenicillin agents are not used to treat Pseudomonas. A GABA analog is used to treat pain related to neuropathy.
A patient is diagnosed with a gram-negative infection and is prescribed an aminoglycoside. What is the action of an aminoglycoside? A) It blocks protein synthesis of the cell wall. B) It blocks DNA replication. C) It destroys the integrity of the cell wall structure. D) It increases white blood cell viability.
Ans: A Feedback: Aminoglycosides penetrate the cell walls of susceptible bacteria and bind irreversibly to 30S and 50S ribosomes, intracellular structures that synthesize proteins. Aminoglycosides do not block DNA replication, destroy cell wall structure, or increase white blood cells.
A patient has been prescribed ciprofloxacin after being diagnosed with a sinus infection. Which of the following should the patient avoid taking concurrently with ciprofloxacin? A) Antacids B) Calcium channel blockers C) Beta-adrenergic blockers D) Diuretics
Ans: A Feedback: Patients should space out ciprofloxacin administration 4 to 6 hours with any of the following: antacids, multivitamins, sucralfate, or other products containing calcium, iron, or zinc. Absorption of ciprofloxacin may be impaired when these substances are administered together with ciprofloxacin, resulting in a decreased antibiotic effect.
A hospital patient has been prescribed ciprofloxacin IV for the treatment of cellulitis. After initiating the infusion of the patient's first scheduled dose, the patient develops a pronounced rash to her chest and arms. How should the nurse respond to this event? A) Discontinue the infusion and inform the care provider promptly B) Slow down the rate so that the infusion takes place over 2 hours C) Administer oral diphenhydramine to the patient during the infusion D) Administer a STAT dose of acetylcysteine
Ans: A Feedback: Severe hypersensitivity reactions have occurred with the administration of fluoroquinolones. The nurse discontinues the antibiotic immediately if skin rash or other signs or symptoms occur. Administration of acetylcysteine or diphenhydramine is not indicated.
An adult male patient with a diagnosis of osteomyelitis will soon begin treatment with gentamicin. Which of the following schedules is most likely to maximize efficacy and minimize nephrotoxicity? A) Gentamicin 500 mg IV OD at 1200 B) Gentamicin 250 mg PO BID at 07:30 and 19:30 C) Gentamicin 500 mg PO TID at 08:00, 12:00, and 17:00 D) Gentamicin 125 mg IV QID at 06:00, 1200, 18:00, and 24:00
Ans: A Feedback: The ODA method uses higher doses (e.g., 4 to 7 mg/kg) to produce high initial drug concentrations, with no repeat dosing until the serum concentration is quite low (typically 24 hours later). The rationale for this dosing approach is a potential increase in efficacy with a reduced incidence of nephrotoxicity. Gentamicin is not administered orally.
A patient is receiving gentamicin (Garamycin) to treat meningitis. The physician has ordered a peak serum level be drawn in association with the 07:00 dose, which will finish infusing at 07:30. When should the peak serum level be drawn? A) 08:00 B) 09:00 C) 10:00 D) 12:00
Ans: A Feedback: With conventional dosing, it is necessary to take gentamicin peak levels 30 minutes after the end of a 30-minute IV infusion. Thus, 8:00 AM is the optimal peak time to assess the serum level of gentamicin.
The nurse is preparing to administer gentamicin (Garamycin) to a patient when he mentions that he has recently been experiencing diminished hearing. What action should the nurse take based on this statement? A) Administer the dosage and notify the physician of the alteration in hearing. B) Hold the dosage and notify the physician of the alteration in hearing. C) Administer the dosage and report the alteration in hearing to the audiologist. D) Hold the dosage and document the finding in the nurses' notes.
Ans: B Feedback: Aminoglycosides accumulate in high concentrations in the inner ear, damaging sensory cells in the cochlea and vestibular apparatus. The medication should be held and alteration in hearing reported to the physician. The administration of the medication will only cause more damage to the cochlea and vestibular apparatus. Holding the medication and documenting the information in the nurses' notes will not allow for a new anti-infective to be administered and for the hearing to be assessed.
A patient has a genitourinary infection and is being treated with a fluoroquinolone. What is the advantage of a fluoroquinolone over an aminoglycoside? A) The fluoroquinolone does not have adverse effects. B) The fluoroquinolone can be given orally. C) The fluoroquinolone has a nearly immediate peak. D) The fluoroquinolone has a broader spectrum.
Ans: B Feedback: Fluoroquinolones are often given orally. Like all drugs, they have adverse effects. Peak levels are not immediately achieved, and they do not have a broader spectrum than an aminoglycoside.
Extreme caution would be necessary with the use of gentamicin in which of the following patients? A) A patient who is morbidly obese and who has primary hypertension B) A patient who has chronic renal failure secondary to diabetes mellitus C) A patient who has bipolar disorder and who is on long-term lithium therapy D) A patient who has an atrioventricular block
Ans: B Feedback: Gentamicin is nephrotoxic, and with impaired renal function, a reduction in dosage is essential. Heart blocks, obesity, and lithium therapy do not severely complicate, or contraindicate, the use of an aminoglycoside.
A patient is prescribed ciprofloxacin (Cipro). Which of the following nursing interventions will best prevent crystalluria? A) The nurse should limit oral fluids to 500 mL/day. B) The nurse should administer 2000 mL of oral fluids per day. C) The nurse should insert a urinary catheter. D) The nurse should administer phenazopyridine (Pyridium).
Ans: B Feedback: Guidelines to decrease the incidence and severity of adverse effects include keeping patients well hydrated to decrease drug concentrations in serum body tissues. The Page 3 administration of 500 mL is not a sufficient amount to prevent crystalluria. The administration of Pyridium will not prevent crystalluria. A urinary catheter is not indicated.
A nurse has informed the laboratory technician that a patient's gentamicin has finished infusing and the technician will soon draw a blood sample to determine the patient's serum drug concentration. Why is assessment of gentamicin levels necessary? A) To identify possible changes in the patient's serum osmolality B) To identify whether the drug is at a therapeutic level C) To identify whether the drug is causing hepatotoxicity D) To identify possible hemolysis following administration
Ans: B Feedback: Measurement of both peak and trough levels of gentamicin helps maintain therapeutic serum levels without excessive toxicity. Gentamicin is nephrotoxic, not hepatotoxic. Hematological changes are not assessed by measuring serum drug levels.
A medical nurse is aware of the need to assess for potential ototoxicity in patients who are being treated with gentamicin. Which of the following patients is likely most susceptible to developing ototoxicity secondary to gentamicin? A) A man who received his first dose of IV gentamicin 12 hours ago B) A man who has required repeated courses of gentamicin over the past several months C) A woman who has a Pseudomonas infection but who has a hypersensitivity to penicillins D) A woman who is immunocompromised and who is being treated with gentamicin
Ans: B Feedback: Ototoxicity (auditory or vestibular) may develop after extended use of gentamicin and may not be reversible. Penicillin allergies and immunocompromised status are not risk factors for ototoxicity
An older adult patient is recovering in hospital from an ischemic stroke and has a feeding tube in place due to dysphagia. The patient has developed an infected pressure ulcer, and ciprofloxacin suspension has been ordered as empiric therapy. How should the nurse follow up this order? A) The nurse should flush the patient's feeding tube with free water before and after administration of the ciprofloxacin suspension. B) The nurse should dilute the suspension thoroughly before administration. C) The nurse should liaise with the care provider to provide an alternative route of administration. D) The nurse should administer small, frequent doses of the drug to minimize GI upset.
Ans: C Feedback: Administration of the oral suspension of ciprofloxacin via feeding tubes should not occur, because the oil-based formulation tends to adhere to the feeding tube. An alternative route is consequently necessary
A patient is scheduled for a bowel resection. He is to receive neomycin sulfate (NeoFradin) by mouth. The patient asks the nurse the purpose of this medication. What is the most appropriate response the nurse can provide to the patient? A) "The administration by mouth will prevent renal damage." B) "The administration by mouth will prevent ototoxicity." C) "The administration will decrease the risk of contamination." D) "The administration decreases the risk of airborne contamination."
Ans: C Feedback: Neomycin can be given before bowel surgery to suppress intestinal bacterial growth. The administration of neomycin will not prevent renal damage or ototoxicity. It will also not affect the risk of airborne contamination.
A patient has been prescribed a once-daily aminoglycoside. What is the advantage of this method of administration? A) It is associated with less hepatotoxicity. B) It is significantly more cost-effective. C) It reduces the risk of nephrotoxicity. D) It increases adherence to treatment.
Ans: C Feedback: The use of once-daily aminoglycoside dosing has replaced the common multiple daily dosing. The rationale for this dosing approach is a potential increase in efficacy with a reduced incidence of nephrotoxicity
A patient has been administered an aminoglycoside. It is time for his next dose, and the nurse learns his creatinine level is elevated at 3.9 mg/dL. What action should the nurse take regarding this assessment? A) Administer the medication and report the creatinine level. B) Hold the dose until another creatinine level is assessed. C) Administer the medication with 100 mL of fluids. D) Hold the medication and assess the urine output.
Ans: D Feedback: Aminoglycosides are nephrotoxic and should not be administered in the presence of renal impairment. It is important to hold the medication, assess the urine output, and notify the physician. The medication should not be administered. The medication should be held, but the creatinine level cannot be reassessed without a doctor's order. The administration with fluids will not protect the patient from renal impairment.
A patient with sepsis is being treated with gentamicin, and her medication regimen takes into account the phenomenon of postantibiotic effects. What are postantibiotic effects? A) The tendency for patients to exhibit symptoms mimicking hypersensitivity after drug administration B) The tendency for adverse effects of a drug to be masked during administration C) The ability of microorganisms to proliferate between doses of antibiotics D) The ability of an antibiotic to kill bacteria even when serum concentrations are low
Ans: D Feedback: Postantibiotic effects mean that aminoglycosides continue killing microorganisms even at low serum concentrations.
A patient is diagnosed with multidrug-resistant tuberculosis. Which of the following aminoglycoside medications is used in a 4- to 6-drug regimen? A) Tetracycline hydrochloride (Achromycin) B) Amoxicillin (Amoxil) C) Sulfadiazine (Sulfisoxazole) D) Streptomycin (Sulfate)
Ans: D Feedback: Streptomycin may be used as part of a 4- to 6-drug regimen for treatment of multidrugresistant tuberculosis. Tetracycline, amoxicillin, and sulfadiazine are not aminoglycosides or drugs of choice for multidrug-resistant tuberculosis.
