What is ototoxicity?
The tendency of certain therapeutic agents to cause functional impairment and cellular degeneration of the end-organs and neurons of the cochlear and vestibular division of the VIIIth cranial nerve is called ototoxicity. These drugs are called ototoxic drugs.
What are the types of ototoxicity?
Depending on the type of inner ear damage, ototoxicity is divided into:
1) Cochleotoxicity: There is damage to the outer and inner hair cells of the cochlea
2) Vestibutotoxicity: Damage to type I and type II sensory hair cells
What are the common ototoxic drugs?
Some of the common ototoxic drugs are as follows:
D) Cytotoxic drugs:
What are the clinical features of ototoxicity?
The clinical features of ototoxicity are as follows:
1) Tinnitus: Tinnitus usually due to toxic damage to the cochlea. It is high frequency and continuous
2) Hearing loss: Initially there is high frequency sensorineural type of hearing loss. It may however progress to involve the speech frequencies. Aminoglycosides commonly cause this type of hearing loss
3) Disequilibrium: When the vestibular organs are damaged, there is inability to focus sharply and distant objects appear to jump on head movements
How is ototoxicity managed?
Management of ototoxicity:
1) Cessation of the treatment by the ototoxic drug
2) Re-assurance for the tinnitus
3) Sound amplification in the form of hearing aid
4) Tinnitus maskers