Here’s what you need to know about ototoxic medications, their possible effects, and what you can do to take care of your hearing if you are taking an ototoxic medicine.

What Are Ototoxic Medications?

“Ototoxic” literally means “toxic to the ear”. It generally refers to any drug, medicine, or chemical that may have the side effect of damaging the inner ear. Why would a doctor knowingly prescribe a medication that can affect your hearing? It’s likely because the benefits outweigh the risks.

Over one hundred medicines are thought to be ototoxic. For example, here are some of the medicines that the European Agency for Safety and Health at Work has confirmed are ototoxic:

• Antibiotics:
  • Aminoglycosides like streptomycin, dihydrostreptomycin, gentamycin, amikacin
  • Certain others: tetracycline antiobitics, erythromycin, vancomycin
• Certain chemotherapy drugs: cisplatin, carboplatin, bleomycin
• Certain diuretics, used to treat things like heart failure, liver cirrhosis, hypertension, water poisoning, or kidney failure: furosemide, ethacrynic acid, piretanide, bumetanide
• Certain painkillers and fever reducers: salicylates, quinine, chloroquine

Ototoxic medications can affect everybody regardless of factors like age or gender. Fortunately, not everybody who takes one of these drugs will experience ototoxic side effects. Some of them, like the chemotherapy drugs, are more likely to have hearing-related side effects, while others are less likely.

Ototoxic Medicine Symptoms

Hearing loss is one of the most common symptoms of an adverse reaction to ototoxic medicine.

Although scientists are still studying exactly how ototoxic medicines cause hearing loss, they’ve found that it’s likely sensorineural hearing loss. Sensorineural hearing loss the most common type of hearing loss and has many different causes. It occurs when delicate hair cells in the inner ear are damaged.

Here’s a before-and-after of how this sensorineural hearing loss affects the hair cells in the inner ear:

See all the stars? Those are places where the hair cells have been damaged by an ototoxic medicine. This image is a magnified close-up of just a small part of the cochlea: there are over 20,000 hair cells in a typical cochlea. These hair cells are responsible for converting sound waves into electrical pulses that the brain understands as hearing. When they are damaged then hearing is also damaged. This can make it difficult to hear both high- and low-pitch sounds.

If you’ve finished the regimen prescribed by your doctor and have stopped taking your medications, will your hearing come back? Unfortunately in many cases this hearing loss is permanent and cannot be cured. However, it can be treated.

What You Can Do

If you’re taking a medicine that’s known or suspected to be ototoxic it’s important to monitor your hearing. Before beginning the treatment go to an audiologist and have your hearing tested. That way you’ll have a baseline reference so you can see how your hearing might change while taking the medicine. Then periodically throughout your treatment have your hearing re-tested and, with your doctor or audiologist, compare these results to previous hearing tests.

Sometimes an ototoxic medicine doesn’t directly cause hearing loss but instead makes the ear more susceptible to loud-noise induced hearing loss. Because of this it’s important that you make sure to protect your hearing by avoiding exposure to loud noises, and use hearing protection for times when loud noises are unavoidable.

If you develop a ringing in your ears or some sounds are becoming more difficult to hear, don’t hesitate to talk with your doctor. Even if a drug is ototoxic your doctor has prescribed it for a reason. It’s critically important that you follow your doctor’s advice and don’t stop taking medications without his or her orders.

And if you do develop a hearing loss know that there are treatments. Depending on the type and severity of your hearing loss these could include hearing aids, middle ear implants, or cochlear implants.

Did you develop a hearing loss after taking an ototoxic medication? Let us know your story in a comment below!