PHARM CHAPTER 39: ANTIBIOTICS PART 2 – Flashcards

A. " The combined effect of both antibiotics is greater than each of them alone" Rationale: Aminoglycosides are often used in combination with other antibiotics, such as beta-lactams or vancomycin, in the treatment of various infections because the combined effect of the two antibiotics is greater than that of either drug alone.

D. Loop Diuretics Rationale: Concurrent use of aminoglycosides, such as gentamicin, with loop diuretics increases the risk for ototoxicity. The other drugs and drug classes do not cause interactions.

C. Hold the drug, notify the prescriber. Rationale: Optimal blood levels of vancomycin are a trough level of 10 to 20 mcg/mL. Measurement of peak levels is no longer routinely recommended, and only trough levels are commonly monitored. Blood samples for measurement of trough levels are drawn immediately before administration of the next dose. Because of the increase in resistant organisms, many clinicians use a trough level of 15 to 20 mcg/mL as their goal. These trough levels mean that even just before the next dose is due, when drug levels should be low, the drug levels are actually too high.

D. D. Colistimethate sodium (Coly-Mycin), a polypeptide antibiotic Rationale: Colistimethate (Coly-Mycin), commonly referred to as colistin, is now being used again, often as one of the only drugs available to treat CRE. The other options are incorrect.

D. Tendonitis and Tendon Rupture Rationale: A black-box warning is required by the U.S. Food and Drug Administration for all quinolones because of the increased risk for tendonitis and tendon rupture with use of the drugs. This effect is more common in elderly patients, patients with renal failure, and those receiving concurrent glucocorticoid therapy (e.g., prednisone). The other options are not common adverse effects.

A.Monitoring serum creatinine levels C. Warning the patient that a flushed feeling or facial itching may occur D. Instructing the patient to report dizziness or a feeling of fullness in the ears F. Reporting a trough drug level of 24 mcg/mL and holding the drug Rationale: Constant monitoring for drug-related neurotoxicity, nephrotoxicity, ototoxicity, and superinfection remain critical to patient safety. Monitor for nephrotoxicity by monitoring serum creatinine levels. Ototoxicity may be indicated if the patient experiences dizziness or a feeling of fullness in the ears, and these symptoms must be reported immediately. Vancomycin infusions may cause red man syndrome, which is characterized by flushing of the neck and face and a decrease in blood pressure. In addition, adequate hydration (at least 2 L of fluids every 24 hours unless contraindicated) is most important to prevent nephrotoxicity. Optimal trough blood levels of vancomycin are 10 to 20 mcg/mL; therefore, the drug should not be administered when there is a trough level of 24 mcg/mL.

A. Liver Disease E. Chronic Renal Disease Rationale: Nitrofurantoin is contraindicated in cases of known drug allergy and also in cases of significant renal function impairment, because the drug concentrates in the urine. Because adverse effects include hepatotoxicity, which is rare but often fatal, the nurse should also question the order if liver disease is present. The other options are not contraindications.