Selective inner hair cell ototoxicity induced by carboplatin

Carboplatin is a second-generation platinum antineoplastic agent. It has biological activity similar to cisplatin and is currently recommended for the treatment of ovarian cancer. In clinical use, carboplatin appears less ototoxic than cisplatin. This paper reports the ototoxic effects of carboplatin, in doses equivalent to the clinical use of the drug, in the chinchilla. Intravenous carboplatin 200 to 400 mg/m2 by bolus injection caused significant ototoxicity in this model as revealed by brainstem evoked responses (ABR audiometry). The cochlear pathology as seen by scanning electron microscopy revealed predominantly inner hair cell (IHC) stereocilia damage. Furthermore, the extent (grade) of the morphological lesions appears to be well correlated with the auditory brainstem response pattern of threshold elevation.