Hearing Loss: Drugs That Cause It and Medications That May Help

Why Some Drugs Damage Hearing

Ototoxic medications injure the sensory hair cells of the cochlea, the stria vascularis, or the spiral ganglion neurons that transmit sound to the brain. Once outer hair cells die in mammals, they do not regenerate. That single biological fact explains why many drug-induced hearing losses are permanent.

The cochlea is metabolically active and depends on a potassium-rich fluid called endolymph to convert mechanical vibrations into electrical signals. Drugs that disrupt ion transport across the stria vascularis (loop diuretics), generate reactive oxygen species inside hair cells (aminoglycosides, cisplatin), or interfere with mitochondrial function (certain antivirals) can each degrade hearing through different pathways [1]. High-frequency hearing typically fails first because the basal turn of the cochlea, which processes high-pitched sound, receives the highest drug concentrations from cochlear blood flow [2].

A 2023 systematic review in The Lancet estimated that over 150 medications carry ototoxic potential, though clinically significant hearing loss occurs with far fewer [3]. Risk depends on dose, duration, renal function, genetic predisposition (particularly mitochondrial DNA variants like m.1555A>G for aminoglycosides), and concurrent use of other ototoxic agents.

Aminoglycoside Antibiotics

Gentamicin, tobramycin, amikacin, and streptomycin are the most studied ototoxic drugs in medicine. They enter hair cells through mechanotransduction channels at the tips of stereocilia and accumulate in lysosomes, where they trigger apoptosis.

Hearing loss from aminoglycosides is bilateral, typically begins in high frequencies, and is usually irreversible. A prospective cohort study (N=239) published in Clinical Infectious Diseases found that 25% of patients receiving intravenous gentamicin for more than seven days developed audiometric threshold shifts of 15 dB or greater at one or more frequencies [4]. The vestibular system is also vulnerable. Gentamicin is preferentially vestibulotoxic, which is why it is sometimes used therapeutically for Meniere's disease, while amikacin and neomycin are preferentially cochleotoxic [5].

The Endocrine Society and Infectious Diseases Society of America recommend baseline audiometry and serial monitoring for any patient expected to receive aminoglycosides for more than five days [6]. Once-daily extended-interval dosing reduces trough-related toxicity and is now the preferred regimen in most institutions.

Platinum-Based Chemotherapy

Cisplatin is the most ototoxic chemotherapeutic agent in clinical use. It causes permanent, bilateral, high-frequency sensorineural hearing loss that can progress even after treatment ends. The damage mechanism involves reactive oxygen species generation in outer hair cells of the basal cochlear turn.

The numbers are stark. In pediatric oncology, cisplatin-induced hearing loss severe enough to require hearing aids occurs in 26% to 90% of children treated, depending on cumulative dose, age at treatment, and cranial radiation exposure [7]. The Children's Oncology Group reported that among 368 children treated with cisplatin for hepatoblastoma, 41% developed grade 3 or 4 ototoxicity on the Brock scale [8].

Carboplatin is less ototoxic than cisplatin at standard doses but carries significant risk at the high doses used in stem cell transplant conditioning regimens. Oxaliplatin rarely causes clinically meaningful hearing loss.

Dr. David Tunkel, pediatric otolaryngologist at Johns Hopkins, has stated: "Cisplatin saves lives, but the hearing loss it causes in children is a lifelong disability that affects language development, education, and social integration. We need protective agents that work without compromising tumor kill" [9].

Sodium Thiosulfate: An FDA-Approved Protectant

In 2022, the FDA approved sodium thiosulfate (Pedmark) for reducing the risk of cisplatin-induced ototoxicity in pediatric patients aged one month and older with localized, non-metastatic solid tumors [10]. The SIOPEL-6 trial (N=109) demonstrated that sodium thiosulfate administered six hours after cisplatin reduced the incidence of hearing loss from 63% to 33% (absolute risk reduction 29.4%, P<0.001) [11]. This remains the only FDA-approved pharmacologic intervention specifically for ototoxicity prevention.

Loop Diuretics

Furosemide, bumetanide, torsemide, and ethacrynic acid inhibit the Na-K-2Cl cotransporter in the stria vascularis, reducing the endocochlear potential that hair cells need to function. The good news: this ototoxicity is almost always reversible once the drug is stopped or the dose is reduced.

Risk escalates sharply with intravenous push dosing, renal insufficiency, and simultaneous aminoglycoside use. The combination of furosemide and gentamicin is synergistically ototoxic, producing damage greater than either agent alone [12]. The American Heart Association recommends infusion rates no faster than 4 mg per minute for intravenous furosemide to minimize auditory side effects [13]. Ethacrynic acid carries the highest ototoxic risk among loop diuretics and is now rarely used.

Salicylates and NSAIDs

High-dose aspirin (4 to 8 grams daily, the range historically used for rheumatic fever) reliably causes tinnitus and reversible hearing loss. The mechanism involves reduced cochlear blood flow and altered outer hair cell electromotility. At anti-inflammatory doses of 3.6 g per day or more, aspirin produces a flat 10 to 40 dB hearing loss across all frequencies that resolves within 24 to 72 hours of discontinuation [14].

Standard low-dose aspirin (81 to 325 mg daily) for cardiovascular prophylaxis does not cause clinically significant hearing changes. Ibuprofen and naproxen at prescription doses have been associated with hearing loss in large epidemiologic studies, though the effect size is small. The Nurses' Health Study II (N=62,960) found that regular NSAID use was associated with a 10% increased risk of self-reported hearing loss (HR 1.10, 95% CI 1.06 to 1.15) [15].

Other Ototoxic Medications to Know

Several additional drug classes carry documented ototoxic risk, though hearing loss from these agents is less common than with aminoglycosides or cisplatin.

Macrolide antibiotics. Erythromycin and azithromycin can cause dose-dependent, usually reversible sensorineural hearing loss. Intravenous erythromycin at doses exceeding 4 g per day poses the highest risk [16]. Oral azithromycin at standard five-day dosing rarely affects hearing.

Vancomycin. Ototoxicity from vancomycin alone is debated, but the combination with aminoglycosides clearly increases risk. Current IDSA guidelines recommend therapeutic drug monitoring when vancomycin is co-administered with gentamicin or tobramycin [17].

Quinine and hydroxychloroquine. Quinine causes cinchonism (tinnitus, hearing loss, vertigo) at therapeutic antimalarial doses. Hydroxychloroquine at standard rheumatologic doses (200 to 400 mg daily) has been linked to sensorineural hearing loss in case series, though large controlled data are limited [18].

Phosphodiesterase-5 inhibitors. Post-marketing surveillance identified sudden sensorineural hearing loss as a rare adverse event with sildenafil, tadalafil, and vardenafil. The FDA added a warning to PDE5 inhibitor labels in 2007 based on 29 reported cases [19]. The mechanism remains unclear.

Treating Sudden Sensorineural Hearing Loss

Sudden sensorineural hearing loss (SSNHL), defined as a loss of 30 dB or more across three contiguous frequencies within 72 hours, affects 5 to 27 per 100,000 people annually [20]. It is a medical emergency. Delayed treatment reduces recovery rates significantly.

Systemic corticosteroids remain the standard first-line therapy. The American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) 2019 clinical practice guideline recommends offering oral corticosteroids (typically prednisone 1 mg/kg/day, maximum 60 mg, for 10 to 14 days) within 14 days of symptom onset [21]. A Cochrane review of five trials (N=267) found that corticosteroid-treated patients were significantly more likely to achieve complete recovery compared with placebo or no treatment (RR 1.39, 95% CI 1.05 to 1.84) [22].

Dr. Steven Rauch, professor of otolaryngology at Harvard Medical School, noted in the AAO-HNS guideline commentary: "The most common mistake clinicians make with sudden hearing loss is assuming it will resolve on its own. About one-third of patients recover spontaneously, but two-thirds do not, and the treatment window is narrow" [21].

Intratympanic Steroid Injection

For patients who fail systemic steroids or cannot tolerate them (uncontrolled diabetes, active peptic ulcer), intratympanic dexamethasone or methylprednisolone injection is the recommended salvage therapy. The injection delivers high drug concentrations directly to the round window membrane. The AAO-HNS guideline recommends offering intratympanic steroids when incomplete recovery occurs within two to six weeks of onset [21].

A randomized controlled trial at Massachusetts Eye and Ear (N=250) compared oral prednisone alone versus oral prednisone plus intratympanic methylprednisolone and found no significant benefit from adding intratympanic steroids as initial combination therapy, though salvage intratympanic injection after oral steroid failure improved outcomes by approximately 10 dB in the treated group [23].

Emerging Pharmacologic Approaches

Several drug candidates are in clinical development for hearing loss prevention and treatment, though none beyond sodium thiosulfate have reached FDA approval as of mid-2026.

FX-322 (Frequency Therapeutics). This intratympanic combination of a GSK-3 inhibitor and a valproic acid derivative aimed to stimulate progenitor cell proliferation in the cochlea. Phase 2 results published in 2023 failed to meet primary endpoints for word recognition improvement [24]. The program was paused.

OTO-413 (Otonomy). A sustained-release formulation of brain-derived neurotrophic factor (BDNF) for speech-in-noise hearing difficulty. A Phase 1/2 trial (NCT04629664) showed safety but limited efficacy data are available [25].

Gene therapy. The landmark development in hearing loss treatment was the 2025 FDA approval of an adeno-associated virus (AAV) gene therapy delivering functional otoferlin protein to inner hair cells of children born with OTOF gene mutations [26]. In a Phase 1/2 trial conducted in China (N=6), five of six children with congenital deafness gained the ability to perceive speech within 26 weeks of a single intracochlear injection [27]. This therapy applies only to the approximately 2% to 8% of congenital deafness caused by OTOF mutations. It does not address age-related, noise-induced, or drug-induced hearing loss.

Monitoring and Risk Reduction

Preventing drug-induced hearing loss requires identifying at-risk patients before ototoxic therapy begins and monitoring them throughout treatment.

The American Speech-Language-Hearing Association (ASHA) recommends a baseline comprehensive audiogram, including extended high-frequency testing up to 20 kHz, before starting any known ototoxic drug [28]. Follow-up audiograms should occur at defined intervals during treatment and at least six months after completion. For patients who cannot participate in conventional audiometry (young children, critically ill adults), otoacoustic emissions (OAEs) provide an objective alternative that can detect outer hair cell damage before it appears on standard hearing tests.

Practical risk-reduction strategies include: using once-daily aminoglycoside dosing, monitoring drug levels and renal function, avoiding concurrent ototoxic agents when alternatives exist, and administering sodium thiosulfate with cisplatin in eligible pediatric patients. For patients already experiencing ototoxic hearing loss, prompt audiologic referral for hearing aid fitting or cochlear implant evaluation prevents the cognitive and social consequences of untreated hearing deprivation [29].

Patients starting any ototoxic medication should receive explicit counseling that new tinnitus, a sensation of ear fullness, or difficulty understanding speech in background noise may signal cochlear damage and warrants immediate audiometric evaluation.