Ototoxic

Ototoxic refers to substances or medications that can cause damage to the inner ear, leading to hearing loss, tinnitus, and/or balance problems. Ototoxic effects may affect the cochlea, responsible for hearing, or the vestibular system, responsible for balance. The risk is influenced by dose, duration of exposure, individual susceptibility, age, kidney function, and concurrent drugs.

Ototoxicity commonly involves damage to cochlear hair cells and other inner-ear structures, usually producing a sensorineural hearing loss that often begins at high frequencies and may progress to lower tones. Vestibular toxicity can cause dizziness, vertigo, and imbalance. In some cases, symptoms may subside after stopping the offending agent, but cochlear damage is frequently irreversible, whereas vestibular symptoms can be partially reversible.

Common ototoxic agents include aminoglycoside antibiotics (such as gentamicin, amikacin, tobramycin), platinum-based chemotherapeutics (notably cisplatin), loop diuretics (such as furosemide, bumetanide, ethacrynic acid), and high-dose salicylates or certain nonsteroidal anti-inflammatory drugs. Other drugs, including certain antivirals and antibiotics like vancomycin, may contribute in susceptible individuals. Ototoxic effects can appear during therapy or after completion, sometimes with delayed onset.

Diagnosis relies on baseline and periodic audiometric testing during exposure, with additional vestibular testing if dizziness or imbalance occurs. Management focuses on minimizing exposure, dose adjustment, or discontinuation of the offending agent when possible, and rehabilitative options such as hearing aids or cochlear implants, as well as vestibular rehabilitation for balance disorders. Prevention emphasizes monitoring drug levels, especially for high-risk medications, and adopting alternatives when feasible.