Which of the following is a key toxicity risk associated with gentamicin therapy?

• A. Nephrotoxicity and ototoxicity
• B. Hepatotoxicity
• C. Hypotension
• D. Hyperglycemia

Answer: (A)

Gentamicin toxicity mainly affects the kidneys and the inner ear. It can accumulate in renal proximal tubule cells, leading to nephrotoxicity, which may present as a rise in creatinine or reduced kidney function and is often reversible with dose adjustment or cessation. It can also accumulate in the hair cells of the cochlea and vestibular system, causing ototoxicity that may present as tinnitus, high-frequency hearing loss, or balance problems; some of this damage can be permanent, especially with prolonged use or higher trough levels. Because of these risks, careful dosing, monitoring of trough levels, and checking renal function are important, along with avoiding other nephrotoxic drugs when possible. Other listed toxicities, like hepatotoxicity, hypotension, or hyperglycemia, are not typical adverse effects associated with gentamicin.