Auditory nerve and brain stem evoked response thresholds in infants treated with gentamicin as neonates.

Thirty-two infants (18 full-term and 14 premature) who had been treated with gentamicin as neonates were examined to ascertain whether this drug induced hearing loss, even of low severity. Objective thresholds to clicks were obtained using auditory nerve and brain stem evoked responses. In addition, behavioral audiometry was performed. Serum concentrations before and after gentamicin treatment were at therapeutic levels. All infants were examined at least 1 1/4 months after cessation of therapy. Normal thresholds were obtained in all ears, with the exception of two with demonstrable middle ear effusion. It appears that gentamicin in therapeutic doses and serum concentrations, in the absence of renal insufficiency, does not cause hearing loss in neonates.