April: Ototoxicity Written by Dr. Madison Cole, Au.D.

There are certain medications that are ototoxic, or toxic to the ear. Ototoxic medications can cause damage to the hair cells within the cochlea, hearing nerve, the blood supply to the ear, as well as the vestibular system. There are three groups of medications that are known to be ototoxic; loop diuretics, aminoglycoside antibiotics, and antineoplastic agents (chemotherapy).

Some symptoms that might be seen due to ototoxic agents are as follows:
Increased difficulty hearing, typically in both ears
Onset or increase of tinnitus (ringing in the ears)
Pressure in the ears
Increased difficulty understanding speech
Difficulty communicating in background noise
Decrease in balance 
Abnormal eye movements

Symptoms can be present after a single dose or delayed by days, weeks, or months. If you are experiencing any of these symptoms after taking an ototoxic medication, it is important to not stop any of the listed medications if you are currently taking them. Rather, talk to your prescribing provider about the possible side effects you might be noticing. Noise exposure during or post-exposure to an ototoxic agent can exacerbate the damage. Remember to always wear hearing protection when in loud environments. Ask your audiologist about custom hearing protection options.

Before starting an ototoxic medication, it is important to have a baseline exam of your hearing. This baseline should include a comprehensive audiological evaluation with extended high-frequency testing, otoacoustic emission testing, tympanometry, and acoustic reflex testing. During the course of treatment with one of these medications, periodic hearing tests should be performed to monitor your hearing status. Ask your audiologist what their recommendation is for how frequent these periodic tests should be. These audiological exams will keep a record if there are any changes to your hearing, as well as provide information to your healthcare team to best manage your medication treatments moving forward.