A review of cis-platinum ototoxicity.

A review of the ototoxic effects of cis-diamminedichloroplatinum (II) (cis-platinum) is presented. Cis-platinum impairs auditory function by preferentially destroying the outer hair cells of the organ of Corti in the basal turn of the cochlea. Hair cell loss in the vestibular labyrinth has also been observed. Auditory sequelae include tinnitus and/or hearing loss, both of which are usually reversible. The incidence of tinnitus in clinical studies is about 7%. Hearing loss is noted in about 69% of patients, usually in the 4,000-8,000 Hz range, although speech frequencies (1,000-4,000 Hz) may occasionally become involved. The hearing losses range from 15-65 dB, and only 7% of all patients complain of difficulty in understanding speech. A direct dose effect relationship does not appear to exist for either tinnitus or hearing loss. The onset of hearing loss, however, appears to be related to cumulative levels of the drug. Vestibular dysfunction has also been shown to be a side effect of therapy. Case management strategies are discussed.