med-surg. Pharm. Chapter 91: Miscellaneous Antibacterial Drugs: Fluoroquinolones, Metronidazole, Daptomycin, Rifampin, Rifaximin, Bacitracin, and Polymyxins

A 65-year-old patient who receives glucocorticoids for arthritis is admitted to the hospital for treatment of a urinary tract infection. The prescriber has ordered intravenous ciprofloxacin [Cipro]. Before administering the third dose of this drug, the nurse reviews the bacterial culture report and notes that the causative organism is Escherichia coli. The bacterial sensitivity report is pending. The patient complains of right ankle pain. What will the nurse do?a. Withhold the dose of ciprofloxacin and notify the provider of the patient's symptoms. b. Instruct the patient to exercise the right foot and ankle to minimize the pain. c. Question the patient about the consumption of milk and any other dairy products. d. Request an order to increase this patient's dose of glucocorticoids.

ANS: A A rare but serious adverse effect associated with fluoroquinolones is tendon rupture, and those at highest risk are children, patients older than 60 years, transplant patients, and any patients taking glucocorticoids. Any pain in either heel should be reported and the drug should be discontinued. Patients should be instructed not to exercise until tendonitis has been ruled out. Dairy products can reduce the absorption of ciprofloxacin, so this is not a concern with this patient. Because the pain may be caused by tendonitis associated with ciprofloxacin, it is not correct to request an increase in the glucocorticoid dosing.

A patient who is receiving intravenous ciprofloxacin for pneumonia develops diarrhea. A stool culture is positive for Clostridium difficile. The nurse will expect the provider to: a. add metronidazole [Flagyl]. testbanks_and_xanax b. increase the dose of ciprofloxacin. c. restrict dairy products. d. switch to gemifloxacin.

ANS: A C. difficile is resistant to fluoroquinolones; metronidazole is the drug of choice to treat this infection. Metronidazole is lethal only to anaerobic organisms, so the ciprofloxacin should be continued to treat the pneumonia. Increasing the dose of ciprofloxacin is not indicated, because C. difficile is resistant to ciprofloxacin. Gemifloxacin is approved for use in respiratory infections.

A nurse is preparing to administer an antibiotic to a patient with methicillin-resistant Staphylococcus aureus (MRSA). The nurse would expect the healthcare provider to order which antibiotic? a. Daptomycin [Cubicin] b. Levofloxacin [Levaquin] c. Norfloxacin [Noroxin] d. Ciprofloxacin [Cipro]

ANS: A Daptomycin is active against MRSA. Levofloxacin and norfloxacin are not approved to treat MRSA. Ciprofloxacin is a poor choice for staphylococcal infections, including MRSA.

Which fluoroquinolone antibiotics may be administered to children? (Select all that apply.) a. Ciprofloxacin [Cipro] b. Levofloxacin [Levaquin] c. Moxifloxacin [Avelox] d. Norfloxacin [Noroxin] e. Ofloxacin

ANS: A,B Ciprofloxacin and levofloxacin are the only two fluoroquinolones approved for use in children.

Which antibiotics may be administered topically? (Select all that apply.) a. Bacitracin b. Daptomycin c. Ofloxacin d. Polymyxin B e. Rifampin

ANS: A,D Bacitracin and Polymyxin B are both topical antibiotics. Daptomycin, ofloxacin, and rifampin are not formulated to be administered topically.

A patient will receive oral ciprofloxacin [Cipro] to treat a urinary tract infection. The nurse provides teaching for this patient. Which statement by the patient indicates a need for further teaching? testbanks_and_xanax a. "I may have abdominal pain and nausea, but these are usually mild." b. "I should take this medication with food or milk to improve absorption." c. "I should stop taking the medication immediately if I experience heel pain." d. "I will need to use sunscreen every time I go outdoors."

ANS: B Dairy products inhibit the absorption of ciprofloxacin, so they should be avoided. Abdominal pain and nausea and vomiting are common and usually mild. Patients should stop taking the drug if heel pain occurs until tendonitis has been ruled out. Photosensitivity can occur, so sunscreen should be used.

A nursing student is caring for a patient with community-acquired pneumonia (CAP) who also has a methicillin-resistant Staphylococcus aureus (MRSA) skin infection. The prescriber has ordered daptomycin [Cubicin]. The nurse encourages the student to approach the provider to request a different antibiotic because of which facts about daptomycin? (Select all that apply.) a. It causes significant renal impairment. b. It is approved only for bloodstream and skin infections. c. It increases the risk of serious cardiorespiratory events. d. It is more likely to produce resistant strains of bacteria. e. It is not effective against MRSA infections.

ANS: B,C Daptomycin has been approved only for bloodstream and skin infections caused by S. aureus, including MRSA infections, and would not be indicated for a CAP infection. In patients with CAP, daptomycin poses a higher risk of serious cardiorespiratory side effects. Daptomycin does not cause renal impairment and is no more likely to produce bacterial resistance than other antibiotics. Daptomycin can be used to treat MRSA infections.

A patient who is taking calcium supplements receives a prescription for ciprofloxacin [Cipro] for a urinary tract infection. The nurse will teach this patient to: a. consume extra fluids while taking the ciprofloxacin to prevent hypercalciuria. b. stop taking the calcium supplements while taking the ciprofloxacin. c. take the two medications together to increase the absorption of both. d. take the calcium either 6 hours before or 2 hours after taking the ciprofloxacin.

ANS: D Cationic compounds, including calcium supplements, can reduce the absorption of ciprofloxacin, so proper interval dosing is necessary. Consuming extra fluids is not indicated. With proper interval dosing, it is not necessary to discontinue the calcium while giving the ciprofloxacin. These two medications should not be given together.

The nurse is caring for a patient who will begin receiving intravenous ciprofloxacin [Cipro] to treat pyelonephritis. The nurse learns that the patient has a history of myasthenia gravis. Which action by the nurse is correct? a. Administer the ciprofloxacin and monitor the patient for signs of muscle weakness. b. Ask the provider whether the ciprofloxacin can be given orally. c. Request an order for concurrent administration of metronidazole [Flagyl]. d. Suggest that the provider order a different antibiotic for this patient.

ANS: D Ciprofloxacin and other fluoroquinolones can exacerbate muscle weakness in patients with myasthenia gravis and should not be given to these patients. It is not correct to administer the drug and monitor for this effect. Giving the drug by a different route will not alter this effect. Metronidazole is given when C. difficile occurs.

A provider orders intravenous moxifloxacin [Avelox] for a patient who has sinusitis. Before administering the drug, the nurse will review this patient's chart for: a. a history of asthma. b. concurrent use of digoxin. c. concurrent use of warfarin. d. recent serum electrolyte levels.

ANS: D Moxifloxacin prolongs the QT interval and poses a risk of serious dysrhythmias. Patients with hypokalemia have an increased risk, so serum electrolyte levels should be monitored. Having a history of asthma is not significant. Moxifloxacin does not alter digoxin or warfarin levels.

A nurse is preparing to administer oral ofloxacin to a patient. While taking the patient's medication history, the nurse learns that the patient takes warfarin and theophylline. The correct action by the nurse is to request an order to: a. reduce the dose of ofloxacin. b. increase the dose of ofloxacin. c. increase the dose of theophylline. d. monitor coagulation levels.

ANS: D Ofloxacin increases plasma levels of warfarin, so coagulation tests should be monitored. The ofloxacin dose should not be reduced or increased. Ofloxacin does not affect theophylline levels.