A client with renal failure is prescribed several medications. Which drug should the nurse question?

A client with renal failure is prescribed several medications. Which drug should the nurse question?

• A. Ampicillin sodium (omnipien-N)
• B. Tobramycin sulfate (Nebcin)
• C. Diphenhydramine hydrochloride (Benadryl)
• D. Calcitriol (Rocaltrol)

Answer: (B)

In renal failure, the safest unifying principle is to avoid or closely monitor drugs that are cleared by the kidneys and that can damage kidney tissue. Tobramycin is an aminoglycoside antibiotic that fits this concern best. It is almost entirely excreted by the kidneys, and in someone with renal impairment, it can rapidly accumulate to nephrotoxic levels. This accumulation increases the risk of kidney injury as well as ototoxicity (hearing loss, tinnitus, balance problems). Because of that, this drug should be questioned, and dosing must be adjusted or an alternative considered. If an aminoglycoside must be used, dosing intervals are often extended or the dose reduced, and trough levels are monitored closely to prevent toxicity. Ampicillin is also renally cleared, but it is not classically nephrotoxic in the same way and can typically be dosed with adjustments as needed. Diphenhydramine isn’t a nephrotoxin and is mainly a sedating antihistamine with anticholinergic effects; it’s not the primary safety concern in renal failure. Calcitriol is a vitamin D analog used to manage calcium balance in kidney disease and is not nephrotoxic; it’s appropriate in this setting with proper monitoring. The key idea is recognizing the drug with the highest risk of nephrotoxicity and accumulation in renal failure, which is tobramycin.

In renal failure, the safest unifying principle is to avoid or closely monitor drugs that are cleared by the kidneys and that can damage kidney tissue. Tobramycin is an aminoglycoside antibiotic that fits this concern best. It is almost entirely excreted by the kidneys, and in someone with renal impairment, it can rapidly accumulate to nephrotoxic levels. This accumulation increases the risk of kidney injury as well as ototoxicity (hearing loss, tinnitus, balance problems). Because of that, this drug should be questioned, and dosing must be adjusted or an alternative considered. If an aminoglycoside must be used, dosing intervals are often extended or the dose reduced, and trough levels are monitored closely to prevent toxicity.

Ampicillin is also renally cleared, but it is not classically nephrotoxic in the same way and can typically be dosed with adjustments as needed. Diphenhydramine isn’t a nephrotoxin and is mainly a sedating antihistamine with anticholinergic effects; it’s not the primary safety concern in renal failure. Calcitriol is a vitamin D analog used to manage calcium balance in kidney disease and is not nephrotoxic; it’s appropriate in this setting with proper monitoring. The key idea is recognizing the drug with the highest risk of nephrotoxicity and accumulation in renal failure, which is tobramycin.