Recent studies from our laboratory have suggested that the ototoxic side effects of
gentamicin are caused by a metabolized or 'activated'form of the drug. Furthermore, we have
postulated that the activation proceeds via the formation of an iron-gentamicin complex and
that this complex produces free radicals. The present study assessed the protective effects of
free radical scavengers and iron chelators on gentamicin-induced ototoxicity in guinea pigs
in vivo. Gentamicin (120 mg/kg per day for 19 days) caused progressive threshold shifts …