The use of cis-platinum as therapeutic drug in malignant neoplasm has associated side effects such as nephrotoxicity and ototoxicity. The nephrotoxic effects of this drug is decreased by use of hydration method. The ototoxic effect, however, cause a irreversible sensorineural hearing loss and incidence of ototoxicity is not changed, so prevention of ototoxic effect is important.

The efficacies of fosfomycin, agent in ameliorating cisplatin induced ototoxicity, are investigated in guinea pig cochleas and the effects of pentoxifylline, agent in therapeutic drug of idiopathic sensorineural hearing loss, are evaluated anatomically by cochlear histology with scanning eletromicroscopy.

Protection against the distortion and injury of outer hair cell according to position of the cochlea caused by cicplatin was statistically significant in groups injected with fosfomycin. Also the injury of hair cells seen in groups injected with both pentoxifyllin and cisplatin was significantly higher than that of cisplatin only group.

Fosfomycin protects against cisplatin induced ototoxicity but pentoxifylline does not protect cesplatin induced ototoxicity.