Abstract: AIM: To study theProtective effects of dexamethasone against ototoxicity of aminoglycoside antibiotics in guineaPigs.METHODS: GuineaPigs were divided into five groups.GrouPOne:gentamycin,im ;GrouPTwo:amikacin,im;GrouPThree:gentamycin +dexamethasone,im ;GrouPFour:amikacin +dexamethasone,im ;GrouPFive:NS,im,all for two weeks.After three weeks,all animals were examined including tympanic mucous membrane reaction,nystagmus depression rates and cochleae morphology.RESULTS: In GrouPThree and Four,the changes of morphology were slighter than those in GrouPOne and Two.CONCLUSION: Dexamethasone can weaken ototoxicity of aminoglycoside antibiotics.

Key words: dexamethasone, gentamycin, amikacin, ototoxicity, guineaPigs