Hearing loss in Charleston is usually the result of aging, noise exposure, disease or side effects of medications.
There are more than 200 drugs that have been identified as ototoxic – that is, having an adverse effect on hearing.
Many of these are antibiotics, but until recently, doctors didn’t know why these medications caused harm to the ears.
Broad-Spectrum Antibiotics & Ion Channels
The list of ototoxic drugs is too lengthy to list in a blog post, but the most common ones include quinine, chemotherapy drugs, loop diuretics, nonsteroidal anti-inflammatory drugs (NSAIDs) and antibiotics – aminoglycosides, in particular.
Antibiotics are essential in the treatment of bacterial infections.
They are classified as either broad-spectrum (targeting a wide range of bacteria) or narrow-spectrum (focused on a specific microbe).
Aminoglycosides such as gentamicin are often used in neonatal intensive care units, where infections can quickly prove fatal and doctors don’t have the luxury of time to wait for lab results.
While great at treating these infections, they increase the risk of hearing loss by as much as six times.
Peter Steyger and a team of researchers from Creighton University in Nebraska set out to examine the link between broad-spectrum antibiotics such as gentamicin and hearing loss.
Working with mice, they administered gentamicin to certain groups and discovered that inflammation caused by infection made the ion channels in the hair cells of the inner ear more permeable, allowing them to absorb more of the antibiotic, increasing the drug’s toxic effects.
The TRPV1 protein, in particular, had a strong negative effect on the ion channels and was especially important in allowing gentamicin to penetrate the hair cells, even when inflammation was occurring.
Some of the mice were genetically bred without the TRPV1 protein, and this group was protected against hearing loss even when inflammation was occurring throughout the body.
The findings from Steyger’s team illustrate how important it is that doctors try to prescribe narrow-spectrum antibiotics whenever possible in order to lower the risk of hearing loss in patients experiencing infections.
There are always going to be instances in which aminoglycosides are the only option, of course; in these cases, doctors should be extra vigilant in monitoring patients for signs of hearing loss.
Solutions such as auditory rehabilitation can improve their chances of a full recovery.
“This is especially important in children learning to listen and speak,” Steyger says, “where delay in identifying hearing loss has lifelong consequences including delayed acquisition of spoken language, less academic success and reduced income.”
Steyger’s research group is pushing for the adoption of new methods to more quickly identify bacteria responsible for infection, limiting the need for broad-spectrum antibiotics.
For more information on ototoxic drugs and hearing loss, contact your Charleston audiologist.
Related Hearing Loss Posts:
- Tips for Removing Water from Your Ears
- Hearing Loss & Heart Disease
- Are Noisy Restaurants Discriminatory?
Our Charleston Area Audiologists Office Locations
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Summerville, SC 29486