Gentamicin (Systemic)

Warning

• Patients should be under close clinical observation because of potential ototoxicity and nephrotoxicity.

• Neurotoxicity (manifested as both auditory and vestibular ototoxicity) can occur, usually in patients with preexisting renal damage and in those with normal renal function who receive doses higher or treatment longer than recommended. Aminoglycoside-induced ototoxicity usually is irreversible. Other neurotoxicity manifestations include numbness, skin tingling, muscle twitching, and seizures.

• Potentially nephrotoxic. Risk of nephrotoxicity is greater in patients with impaired renal function and in those who receive high dosage or prolonged treatment.

• Monitor renal and eighth-cranial nerve function closely, especially in patients with known or suspected renal impairment at start of treatment and also in those whose renal function is initially normal but develop renal dysfunction during treatment. Evaluate urine for decreased specific gravity and increased excretion of protein, cells, and casts; periodically determine BUN, S_cr, and Cl_cr.

• Serial audiograms should be obtained, if feasible, in patients old enough to be tested, particularly in high-risk patients. Discontinue or adjust dosage if there is evidence of ototoxicity (dizziness, vertigo, tinnitus, roaring in the ears, hearing loss) or nephrotoxicity. Rarely, changes in eighth-cranial nerve and renal function may not manifest until after the drug is discontinued.

• Monitor serum gentamicin concentrations, when feasible, to assure adequate concentrations and avoid potentially toxic and prolonged peak concentrations (>12 mcg/mL) and avoid trough concentrations >2 mcg/mL. Excessive peak and/or trough serum concentrations may increase risk of renal and eighth-cranial nerve toxicity. In the event of overdose or toxic reactions, hemodialysis may aid in removal of g...