Ototoxicity (Ear Poisoning)

Sometimes kids who take high doses of drugs for cancer, infection, or other illnesses develop hearing or balance problems (or both) as a result of taking the drugs. When a medication damages the inner ear — the part of the ear responsible for receiving/sending sounds and controlling balance — it's called ototoxicity or "ear poisoning."

The degree of damage to the ear depends on what type of drug a child is taking, how much, and for how long. And the severity can vary from child to child. Some kids may have no or very minimal hearing loss and "ringing in the ears" (tinnitus), while others may experience major problems with balance and/or profound hearing loss (deafness).

Fortunately, when ototoxicity is caught early, doctors can try to prevent problems from becoming worse and get kids the rehabilitation they need to address the damage that's been done.


Signs and Symptoms
Some kids may notice obvious 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. Or they may have tinnitus, which can cause not just that annoying ringing in the ears but other strange sounds like hissing, buzzing, humming, and roaring.
Sometimes, though, there's only limited damage, and kids might not even notice a problem. Or they might just have a hard time hearing high-frequency sounds while everything else sounds perfectly clear. As a parent, it can be hard to tell at any given moment whether your child can't hear you or (like most kids) just isn't listening or paying attention.

Most kids with hearing problems:
have limited, poor, or no speech
are frequently inattentive
have problems in school or difficulty learning
need to constantly turn up the volume on the TV or stereo
fail to respond to conversation-level speech or answer appropriately (babies and pre-verbal children fail to "startle" or turn their heads when they hear a loud sound)
When balance is affected, kids may fall frequently and have symptoms of disequilibrium — an unsteady "woozy" feeling that makes it hard to stand up, walk, or climb the stairs without falling. They may walk with their legs too far apart or be unable to walk without staggering. And walking in the dark can also be tricky.

In the most severe cases, vision also can be affected and kids may see images that bounce, jump erratically, or look blurry whenever they move their heads (called oscillopsia). As a result of balance and vision problems, kids may get headaches often, or feel lightheaded, dizzy, or disoriented. Nausea, vomiting, and diarrhea also might occur, as can changes in heart rate and blood pressure.

The symptoms of ototoxicity can come on suddenly after a course of medication or show up gradually over time.