Tkontheweb.com

Ototoxins
Ototoxic agents are either man made or naturally occurring substances and chemicals knownto damage the ear. The study of Ototoxins is relatively new. Promising research is ongoing inan effort to explain how ototoxins damage the human ear and what can be done to eliminate orminimize risk of hearing loss as result of exposure.
Ototoxic agents are in forms of heavy metals, solvents, asphyxiant gases, medications, andcertain mother-in-laws.
In the early to mid 1900s, many Aminoglycoside anti-biotics were developed to fight infection.
These high-powered drugs saved many lives; it was unknown, however, that these new anti-
biotics were causing significant hearing loss. Aminoglycoside anti-biotics are still used today in
extreme cases. Most current day anti-biotics leave the auditory mechanism in tact. Known
ototoxic anti-biotics are:
Life-saving medical procedures most always take precedence over potential ill side effects.
Advances in cancer treatment have developed Anti-Neoplastics. A major anti-cancer drug
responsible for hearing loss is Cisplatin. Cisplatin is still commonly utilized in high doses to
treat highly difficult forms of cancer such as Ovarian and Bladder cancer. Known ototoxic anti-
Neoplastics include:
Diuretics are well represented in the family of ototoxins. Hearing loss due the ingestion of
diuretics is often reversible. However, the use of diuretics in conjunction with aminoglycoside
anti-biotics will permanently damage the aural mechanism. Known ototoxic diuretics include:
2008 T K Group, Inc.
1781 S. Bell School Rd. | Cherry Valley, IL 61016
Phone: 815.332.3460 | Fax: 815.332.5175
Company Website: http://www.tkontheweb.com
Quinines (drugs used to treatment Malaria and similar diseases) are documented ototoxins.
Known ototoxic quinines include:
Many Environmental Chemicals used today in industry are known ototoxins. The full effect
upon the aural mechanism resulting from either heavy or casual exposure to these agents is
under investigation. Of great interest is the combined effect of environmental ototoxic
chemicals and noise exposure. Research studies using laboratory animals are showing that
the interaction of noise combined with ototoxic drugs and/or environmental agents is
significantly damaging.
Many industrial solvents are ototoxic. Solvents damage the aural mechanism by affecting theeither the hair cells within the cochlea directly, or by affecting the ear associated neuralpathways of the central nervous system.
Toluene (used as thinners and degreasers) is commonly used in today s industry. CarbonDisulfide is another ototoxin commonly seen in the textile industry.
Known environmental chemicals and solvents include: 2008 T K Group, Inc.
1781 S. Bell School Rd. | Cherry Valley, IL 61016
Phone: 815.332.3460 | Fax: 815.332.5175
Company Website: http://www.tkontheweb.com
Finally, Aspirin is a known Ototoxin. Individuals with Arthritis often heavily use aspirin. Hearing
loss caused by the ingestion of aspirin is reversible when ingestion of the substance is ceased.
The presence of potential ototoxic interactions underlines the importance of obtaining acomplete aural case history when performing industrial audiometry. Knowledge of significantpast ototoxin exposure may certainly be useful information when evaluating occupationalhearing loss.
Research may in the future allow the development of tests to evaluate hearing losses
attributable to ototoxic exposure. It is most probable that any hearing loss due truly to ototoxic
exposure in industry is due to chronic long- term exposure-not one or two time exposure.
_________________________________________________________
Authored by: Robert Williams, Au.D. | Director Audiology | T K Group, Inc.
2008 T K Group, Inc.
1781 S. Bell School Rd. | Cherry Valley, IL 61016
Phone: 815.332.3460 | Fax: 815.332.5175
Company Website: http://www.tkontheweb.com

Source: http://www.tkontheweb.com/documents/support/Ototoxins.pdf