Effect Of Ototoxicity On Hearing

By Katie Kirleis, AuD

What Is Ototoxicity?

Medications that can cause temporary or permanent damage to hearing and/or balance are considered ototoxic. Ototoxicity may damage the cochlea (inner ear) and the vestibule cochlear nerve (nerve that sends hearing and balance information to the brain). The result may include hearing loss, balance disturbance, and/or tinnitus (the perception of sound in the ears or head).

What Drugs Are Ototoxic?

Many drugs and chemicals have ototoxic potential, including antibiotics, loop diuretics, and chemotherapy agents. The extent of damage depends on the substance, dosage, duration of exposure, and other individual patient factors. In some cases, full recovery is possible once the drug is no longer taken. With that said, medication should not be stopped without first discussing further with your medical professional.

Loop diuretics are known as water pills and may cause tinnitus or decreased hearing acuity that typically reverses when discontinued. Antibiotics, specifically of the amino glycoside family are typically linked to permanent hearing loss. The risk of permanent hearing loss increases with increased amounts of the drug that enters the blood stream.

Chemotherapy agents not only work to eliminate cancer cells, but may also have damaging effects on other cells in the body, including the ears. Hearing decrement and imbalance are possible side effects and can be evaluated throughout the process. Slower deterioration may cause a feeling of being off balance or unsteadiness while a more rapid decline may cause a spinning sensation of oneself or the room (vertigo) and nausea.

Why Should Testing Be Completed?

Changes in hearing and balance may not be recognized during treatment. Often, changes are gradual, making it more difficult for an individual to realize them. A pre-treatment comprehensive audiometric (hearing) evaluation is important to establish a baseline for monitoring changes. Ototoxicity commonly effects high-frequency hearing, at least initially. When hearing depredation begins to appear in the speech frequency range, an audiologist can provide strategies to the patient to improve communication. Other assistive devices or hearing aids may be discussed as options to improve daily communication.

Ototoxicity monitoring is intended for early identification and potentially allows the physician(s) to determine if any alterations to medication, dosage, or frequency of the drug would be beneficial or possible. In cases where the drugs cannot be discontinued or altered, the patient and audiologist can work together to manage the effects of hearing loss.