Cochleotoxicity of otic drops in the chinchilla: Comparative study of Bestron and Cortisporin

Bestron,® a new otic preparation containing cefmenoxime, was applied to the round window membrane of the chinchilla and the long-term cochleotoxicity was evaluated by means of electrocochleography. The thresholds of the compound action potential (CAP) in all frequency areas tested ranged within normal values. The input-output and -latency relationships of the CAP resulted in no significant deterioration of hearing. However, identical treatment with Cortisporin® resulted in elevated CAP threshold in the high frequency area and deterioration of the input-output and -latency of the GAP. These findings indicate that Bestron is noncochleotoxic as compared with Cortisporin and therefore may be used safely in the treatment of infected ears.