The comparative ototoxicities of panimycin and gentamicin in cynomolgus monkeys (Macaca fascicularis).

In order to comparatively examine damage to vestibular and auditory organs, aminoglycoside antibiotics, panimycin (DKB) and gentamicin (GM), were intramuscularly injected to cynomolgus monkeys in an identical daily dose regimen (25 and 50 mg/kg) for a 35-day period. No damage to these organs was found in the DKB 25 mg/kg group, but slight vacuole formation was found in 33% of the cristae ampullares in the DKB 50 mg/kg group. In the GM 25 mg/kg and GM 50 mg/kg groups, similar vacuole formations, as well as sensory hair cell loss even at the basal end of the cochlea were found. Compared to the DKB groups, the GM groups exhibited greater damage to the vestibular and auditory organs, and even fatal effects. The ototoxicity of GM seemed to be stronger in cynomolgus monkeys than in guinea pigs.