Which medication should the nurse question in a client with renal failure?

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

Answer: (D)

In renal failure, drugs cleared by the kidneys can accumulate and cause toxicity, especially those with inherent nephrotoxicity. Tobramycin sulfate is an aminoglycoside that is almost completely eliminated by the kidneys. Its major risks are nephrotoxicity and ototoxicity, so when kidney function is impaired, its clearance drops and drug levels can rise to harmful levels. Because of that, the nurse should question continuing standard dosing or administration of tobramycin in a client with renal failure and coordinate a dose adjustment or an alternative therapy with the prescriber, while monitoring levels if its use is necessary.

The other medications are not as critically problematic in this context: calcitriol is used to manage mineral and bone disorders in renal disease and is dosed accordingly; diphenhydramine can be used with caution in renal impairment; ampicillin often requires dose modification but is not inherently nephrotoxic in the same way aminoglycosides are.