Two mechanisms, two very different endings. Aminoglycoside antibiotics (gentamicin, tobramycin, amikacin, streptomycin) and the chemo drug cisplatin get pulled into hair cells and poison them dead ¹. Those cells don't come back, and the drug keeps killing for weeks after the last dose because it lingers in inner-ear fluid. Loop diuretics like furosemide only drain the cochlea's chemical battery without killing anything, so hearing returns when the drug clears ². High-dose aspirin jams the cells' motor protein; the ringing fades within a day or two of stopping ³.

The numbers sort the list. Aminoglycosides damage hearing in 10–25% of people on one course, over 50% on repeated courses ¹. Cisplatin does permanent damage in 40–80% of adults. About 1 in 500 people carry a variant, m.1555A>G, that makes a single gentamicin dose enough to deafen them for life ⁴.

The over-the-counter end surprises people. Taking ibuprofen, naproxen, or acetaminophen twice a week or more raises new hearing-loss risk by about 20% ^{5 6}. The signal sits in chronic use; the occasional headache pill is fine. Low-dose aspirin, the 81 mg heart dose, is clean.

Gentamicin also has a stranger target: the balance organ. You don't spin, the world bounces when you turn your head, and standard hearing tests come back normal ⁷. It gets missed for years.

If any of these drugs is being prescribed, three conversations do most of the work.

What the asking buys you. For the two-week gentamicin course, a baseline plus a day-three report is often the line between full recovery and a loss the audiologist later blames on age. For chronic ibuprofen, swapping to a controlled or non-drug pain plan takes the yearly risk back off the table. Cisplatin has an actual antidote now: sodium thiosulfate roughly halves hearing loss in kids and is FDA-approved for them, so ask whether it fits your case ^{9 10}.