A nurse is caring for a client with a urinary tract infection and a history of chronic kidney disease. Which antibiotic should the nurse expect to be prescribed with caution due to renal impairment?

Choice A reason: Nitrofurantoin is excreted primarily by the kidneys, and in chronic kidney disease, reduced clearance increases toxicity risk, including pulmonary and neurologic side effects. It is contraindicated in significant renal impairment (GFR <60 mL/min), requiring cautious use or alternative antibiotics to avoid harm in this population. Choice B reason: Ciprofloxacin is partially renally excreted, but dose adjustments allow safe use in chronic kidney disease. It is effective for urinary tract infections and less likely to accumulate to toxic levels compared to nitrofurantoin, making it a safer choice with proper renal dosing considerations. Choice C reason: Amoxicillin is renally excreted but safe in chronic kidney disease with dose adjustments. It is commonly used for urinary tract infections, and its favorable safety profile in renal impairment makes it less concerning than nitrofurantoin, which has specific contraindications in low GFR settings. Choice D reason: Azithromycin is primarily hepatically metabolized, not renally, so it is safe in chronic kidney disease without significant dose adjustments. Its use for urinary tract infections is limited, but it poses minimal risk of toxicity in renal impairment, unlike nitrofurantoin’s high renal clearance dependency.