AUDITORY IMPAIRMENT IN GUINEA-PIGS TREATED WITH ISEPAMICIN

Groups of adult guinea pigs were treated intramuscularly with isepamic in at doses of 100, 150 and 225 mg/kg/day for 21 days. For comparison, two other groups were administered either saline or amikacin 225 mg/k g/day. Auditory function, as measured by the Preyer pinna reflex and t he brain stem evoked response, was impaired in both the isepamicin and amikacin groups treated with 225 mg/kg/day, and to a lesser extent in the group receiving isepamicin 150 mg/kg/day. Morphological evaluatio n of the organ of Corti, performed either by scanning electron microsc opy or by light microscopy, showed the typical pattern of damage assoc iated with the aminoglycosides. The greatest damage was observed at 22 5 mg/kg/day, with no difference between isepamicin and amikacin. Isepa micin 100 mg/kg/day produced no impairment in auditory function and ve ry little change in the morphology of the organ of Corti.