Effect of intratympanic dexamethasone administration on cisplatin-induced ototoxicity in adult guinea pigs

Abstract

To evaluate the effect and safety of intratympanic dexamethasone administration on cisplatin-induced ototoxicity in adult male guinea pigs and to assess the differences between early and late protection from this ototoxicity. Forty eight adult male guinea pigs were divided as follows: group I served as control group. Group II was subjected to intratympanic saline (subgroup IIa) or dexamethasone (subgroup IIb) injection. Group III was intraperitoneally injected with cisplatin. Groups IV and V were subjected first to intratympanic dexamethasone administration in both ears for 5 days starting 1 day and 1h - respectively - before cisplatin intraperitoneal injection. Dexamethasone intratympanic injection revealed similar functional and structural results compared with control. Cisplatin intraperitoneal injection resulted in a profound cochlear functional and structural damage in group III. Non-significant otoprotection resulted from intratympanic dexamethasone administration one day before cisplatin. Intratympanic dexamethasone injection 1h before cisplatin treatment resulted in a significant preservation of the functional and structural properties of the cochlea. Intratympanic dexamethasone administration is a safe, easy and efficient way to protect from cisplatin ototoxicity especially when administered 1h before cisplatin treatment.