Immediate effects of tobramycin on human cochlea and correlation with serum tobramycin levels

Electrocochleography was performed on three patients to monitor the intravenous administration of tobramycin. When peak serum tobramycin levels exceeded 8-10 mug/ml an immediate dramatic reduction in cochlear output was observed, which recovered fully as serum levels fell. The patients had no auditory or vestibular symptoms either during or after treatment.