Ototoxicity is when a person develops hearing or balance
problems due to a medicine. This can happen when someone is on a high dose of
a drug that treats cancer, infections, or other illnesses.
When doctors find ototoxicity (oh-tuh-tok-SISS-ih-tee) early, they may be able
to prevent it from getting worse. They also can help kids find the right treatments
and therapies to manage problems the condition can cause.
What Happens in Ototoxicity?
Ototoxicity damages the inner ear. This part of the ear
gets and sends sounds and controls balance. How much damage happens depends on:
the type of medicine causing it
how much medicine the child got
how long the child took the medicine
What Are the Signs & Symptoms of Ototoxicity?
The symptoms of ototoxicity can come on suddenly or show up over time.
Kids with ototoxicity might have:
minimal hearing loss but not notice a problem
"ringing in the ears" (tinnitus). This also can cause strange
sounds like hissing, buzzing, humming, and roaring.
major problems with balance
hearing problems, usually in both ears (called bilateral hearing loss).
They may have trouble hearing certain things, from high-pitched sounds to talking
if there's background noise.
profound hearing loss (deafness)
Signs of hearing problems include:
limited, poor, or no speech
not seeming to pay attention
problems in school or trouble with learning
turning up the volume on the TV or stereo
not responding to conversation-level speech or noises as expected. Babies and
kids who aren't talking yet won't react to or turn their heads when they hear a loud
becoming tired more quickly or more often after hours of careful listening (such
as after school)
Signs of balance problems include:
falling a lot
an unsteady "woozy" feeling that makes it hard to stand up, walk, or climb the
stairs without falling
have trouble with reading, such as needing time to adapt their vision when switching
from reading a book to reading something at a distance
Nausea, vomiting, diarrhea, and changes in heart rate and blood pressure also can
The most severe cases might affect vision.
Kids may see images that bounce, jump around, or look blurry whenever they move their
heads. This is called oscillopsia (ah-sih-LOP-see-uh).
How Is Ototoxicity Diagnosed?
There's no way to test if a drug has caused ototoxicity. When a child has signs
of a problem, the doctor may do hearing or balance tests. Often, they refer kids to
an audiologist or otolaryngologist (ear, nose, and throat specialist, or ENT) for
These tests can include:
Behavioral hearing tests. These involve watching a child's response
to sounds like calibrated speech and pure tones. Pure tones are the distinct pitches
(frequencies) of sounds. The tests track the thresholds of hearing for various sounds.
brainstem response (ABR) test. Tiny earphones go in the ear canals and
electrodes (small stickers) go on the scalp and behind the ears. The electrodes measure
the responses from the auditory (hearing) nerve and other important auditory centers
in the brain stem.
Otoacoustic emissions (OAE) test. A tiny probe goes in the ear
canal, then many pulse-type sounds are introduced. An "echo" response from cells in
the inner ear is recorded. A normal recording means that the inner ear amplifies sounds
normally. This test, along with the ABR, is often used on newborns, babies, and young
Electronystagmogram (ENG). This test checks balance. A computer
records involuntary eye movements as the child looks at a moving target or moves the
head up and down, or after an injection of warm or cold water into the ear canal.
Posturography. This measures how well a child balances while standing
on a stable or unstable platform.
Balance questionnaires. Kids old enough to describe a medical
problem might write down their level of dizziness throughout the day as they do different
How Is Ototoxicity Treated?
Research continues on ways to prevent ototoxicity or fix the damage it can cause.
So far there's no sure way to reverse it.
The good news is that sometimes the ear just needs time to heal. And some kids
may have no further hearing or balance problems if they can stop taking the medicine
that's causing their symptoms.
Sometimes, doctors might change the dosage or the medicine. But that's not always
an option. Some drugs are key to fighting an infection or disease.
When switching to a different drug or reducing the dose isn't possible, auditory
or listening therapy and speech (lip) reading can help.
What Can Help With Hearing Loss?
Kids with serious damage to the inner ear may need an amplification device, hearing
aid, or cochlear implant:
An amplification device called an FM system can help reduce background
noise. Some classrooms have FM systems, or "auditory trainers," to improve hearing
in group or noisy environments. These also can be fitted for personal or home use.
Other assistive listening or alerting devices may help older kids.
Hearing aids can fit inside or behind the ear and make sounds
louder. An audiologist adjusts them so that the sound coming in is amplified enough
to let a child hear it well.
Sometimes, the hearing loss is so severe that the most powerful hearing aids can't
amplify the sound enough. In those cases, doctors might recommend a cochlear implant:
implants are surgically implanted devices. They bypass the damaged inner
ear and send signals right to the auditory nerve. A small microphone behind the ear
picks up sound waves and sends them to a receiver under the scalp. The receiver sends
impulses to the auditory nerve. These signals are sensed as sound and let the person
Kids with balance problems will have balance therapy, or vestibular rehabilitation.
They'll work with a physical
therapist or a vestibular therapist (someone trained in treating balance problems).
Therapy might include exercises to help balance skills and coordination. These can
standing or walking with eyes open and then with eyes closed
having the therapist position the child's head at different angles to move fluid
or debris out of certain parts of the ear
How Can Parents Help?
Problems from ototoxicity aren't always easy to notice. Kids with minimal hearing
loss might have symptoms that don't seem worth telling parents or doctors about. Some
may not notice anything at all. Balance problems can be even tougher to spot, because
kids have a harder time than adults recognizing and describing them.
So, before your child takes any new medicine, ask your doctor what side effects
it might cause and what you should look for. To watch for problems with drugs that
have a major ototoxicity risk, doctors may recommend that a child see:
a vestibular therapist
Follow the testing schedule the doctor gives you, even if you don't notice any
change in hearing or balance. Regular, repeated testing is the best way to catch an
ototoxic effect early.
What Else Should I Know?
The sooner doctors diagnose ototoxicity, the sooner a child's treatment can begin.
In the youngest kids, it's especially important to catch it early. To develop their
speech and language skills, babies and toddlers need to hear voices and conversations
clearly. Hearing problems in older kids can affect how they socialize, communicate
with others, and do in school.
Balance problems can have a huge effect on kids of any age, and can put them at
risk for dangerous falls.
If your child has hearing and/or balance problems while on high doses of medicines,
talk to your doctor. Mention all symptoms, even if they don't seem related. You might
not think things like trouble walking or paying attention in school could have anything
to do with the ears, but they might.
If you're concerned about any medicine your child is taking, call your doctor.
But don't change the dose or stop giving your child a medicine without talking to
your doctor first.