Ototoxic Drug Essay

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Ototoxic Medications That Cause TinnituOtotoxic medications are those that are toxic to the cochlea or vestibular (balance) structures in the ear. These medications have the potential to cause hearing loss, tinnitus and/or dysequilibrium such as dizziness and vertigo. Ototoxicity came to the forefront of clinical attention with the discovery of streptomycin in 1944. Streptomycin was successfully used in the treatment of tuberculosis; however, a large number of patients were found to develop irreversible cochlear and vestibular dysfunction. Ototoxicity was also shown with the later development of other aminoglycoside antibiotics. Today, many well known pharmaceutical agents have been shown to have toxic effects on the cochleovestibular system. The list includes aminoglycosides and other antibiotics, platinum-based chemotherapy medications, salicylates, quinine and loop diuretics.The method of action of ototoxic medications differs somewhat among the various drugs. Aminoglycosides seem to potentiate glutamate receptors in the cochlea that promote degeneration of hair cells and cochlear neurons.1 This, in turn, generates a cascade of free radical damage which leads to the destruction of hair cells and neurons.2 The damage typically begins with the inner row of outer hair cells and progresses through the other rows, then to the inner hair cells. Patients frequently develop symptoms following the cessation of therapy. Ototoxicity-induced hearing loss tends to first manifest in the high frequencies and often causes tinnitus. It then progressively involves the lower frequencies and eventually affects speech recognition.3 Since free radical damage is central to lost hearing and vestibular disturbances, it makes sense that taking antioxidants before being exposed to ototoxic medications will reduce the pOtotoxicity may be reversible or may be permanent, depending on the type of medication used, dosage and duration of treatment. There are many other medications that...