Ototoxicity is the property of being toxic to the ear (oto-), sometimes as a drug side-effect.
The effects of ototoxicity, although possibly reversible and temporary, can be irreversible and permanent. Many ototoxic drugs are well known and used in clinical situations. These include those often prescribed for very serious health conditions, despite the risk of hearing disorders. Ototoxic drugs include antibiotics such as gentamicin, loop diuretics such as furosemide and platinum-based chemotherapy agents such as cisplatin. A number of nonsteroidal anti-inflammatory drugs (NSAIDS) have also been shown to be ototoxic.
This can result in sensorineural hearing loss, dysequilibrium, or both. Select environmental and occupational chemicals have also been shown to not only affect the auditory system and interact with noise and increase the negative effects of noise on one’s hearing.
Symptoms of ototoxicity include partial or profound hearing loss, vertigo, and tinnitus.
Ototoxic effects are also seen with quinine, pesticides, solvents, asphyxiants and heavy metals such as mercury and lead. When combining multiple ototoxins, the risk of hearing loss becomes greater.
Ototoxic chemicals in the environment (from contaminated air or water) or in the workplace interact with mechanical stresses on the hair cells of the cochlea in different ways. For organic solvents such as toluene, styrene or xylene, the combined exposure with noise increases the risk of hearing loss in a synergistic manner. Carbon monoxide, has been shown to increase the severity of the hearing loss from noise. Given the potential for enhanced risk of hearing loss, exposures and contact with products such as paint thinners, degreasers, white spirits, exhaust, should be kept to a minimum. Noise exposures should be kept below 85 decibels, and the chemical exposures should be below the recommended exposure limits given by regulatory agencies.
Drug exposures mixed with noise potentially lead to increased risk of ototoxic hearing loss. Noise exposure combined with the chemotherapeutic cisplatin puts individuals at increased risk of ototoxic hearing loss. Noise at 85 dB SPL or above added to the amount of hair cell death in the high frequency region of the cochlea In chinchillas. The American Academy of Audiology recommends people being treated with ototoxic chemotherapeutics avoid excessive noise levels during treatment and for several months following cessation of treatment. Opiates in combination with excessive noise levels may also have an additive affect on ototoxic hearing loss.
Other Medicinal Ototoxic drugs & agents include but are not limited to some varieties of Antibiotics, Loop Diuretics, Chemotherapeutic agents, Antiseptics and disinfectants. Even high doses of quinine, aspirin and other salicylates may also cause high-frequency tinnitus and hearing loss bilaterally, typically reversible upon discontinuation of the responsible drug. The erectile dysfunction medications Viagra, Levitra, and Cialis have also been reported to cause hearing loss.
Successful monitoring includes a baseline test before, or soon after, exposure to the ototoxin. Follow-up testing is completed in increments after the first exposure, throughout the cessation of treatment. Shifts in hearing status are monitored and relayed to the prescribing physician to make treatment decisions.
Make sure to ask your Pharmacist about ototoxic medicines and have your baseline hearing identified by the Viva Care Hears program.
