The Vestibular Disorders Association describes ototoxicity as ear poisoning (oto = ear, toxicity = poisoning), which results from exposure to drugs or chemicals that damage the inner ear or the vestibulo-cochlear nerve (the nerve sending balance and hearing information from the inner ear to the brain). Because the inner ear is involved in both hearing and balance, ototoxicity can result in disturbances of either or both of these senses.
Simply put, ototoxicity is the damage certain medications cause to the inner ear system resulting in hearing loss, ringing in the ear or problems with balance. When medications affect the ear and balance mechanisms, they are identified as ototoxic. There are currently over 200 medications that are considered ototoxic, both prescribed and over the counter. In many cases the damage to the hearing and balance is temporary and may reverse itself once the treatment is discontinued. Still, in many other cases, the damage is permanent, resulting in irreversible tinnitus, hearing loss and/or balance disorders.

Use of ototoxic medications
Nonetheless, despite the risk to the hearing and balance system, ototoxic medications are prescribed when necessary, to treat very serious illnesses or other life-threatening medical conditions like cancer, heart disease and various types of serious infections.

Signs and symptoms of ototoxicity
Ototoxic medications cause damage to the sensory cells of the inner ear that are related to our ability to hear precisely and to maintain proper balance. Signs and symptoms of ototoxicity include ringing in the ears, hearing loss and dizziness or vertigo.
o Ringing or buzzing noises (tinnitus) in the ear is usually the first sign that an ototoxic medication is affecting the inner ear mechanism.
o Hearing loss normally follows the tinnitus and typically occurs in both ears starting with the high frequencies. It may appear suddenly or it may be gradual. However, in most cases, the hearing loss is not noticed until you begin having difficulties understanding conversational speech.
o Ototoxic medications may also affect your balance. You may begin by feeling a bit unsteady on your feet, or you may feel like things around you are spinning.

Ototoxic medications
Some of the more common ototoxic drugs include aminoglycoside antibiotics such as gentamicin, kanamycin, neomycin, amikacin and streptomycin; loop diuretics such as furosemide, ethacrynic acid and bumetanide; platinum-based chemotherapy agents such as cisplatin; and salicylate pain relievers such as aspirin, used to treat heart conditions.
The precise workings of the mechanisms of the ear are essential for us to have accurate hearing and balance function. Hearing is one of our most critical senses, and without the capacity to hear, a patient's ability to interact with people and the environment becomes extremely compromised. The effects of ototoxic medications therefore not only affect hearing and balance, but can also affect quality of life. Not being able to hear the conversations of family, friends and loved ones, or even a physician may leave a patient feeling isolated and depressed. Constant dizziness may also cause a patient to stop participating in normal activities, as it makes something as simple as walking or driving difficult or impossible to accomplish.
If you or someone you know is taking an ototoxic medication or suffering from ototoxicity, speak to your doctor regarding the possible hearing-related side effects so that you know what to expect and what to look for. Have your hearing checked both before and during medical treatment of ototoxic medications. This gives a baseline of your hearing and helps with monitoring and identifying any changes to your hearing during treatment as quickly as possible. Do not discontinue taking your medication. Certain medications are vital to fighting specific infections or diseases and may have to be continued. Always consult your physician if you are having any concerns regarding your medication. Although researchers are trying to develop ways of protecting patients from ototoxicity, there is currently no protective strategy that has been approved.
To have your hearing monitored while taking ototoxic medications, contact an audiologist.

o For further information on any hearing-related disorder, please contact Dr. Deborah Nubirth, doctor of audiology, at 356-2276 or 677-6627 in New Providence at Comprehensive Family Medical Clinic, Poinciana Drive or 351-7902 in Grand Bahama; or email dnubirth@yahoo.com.

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