Ototoxic effect of topical oxiconazole and terbinafine in rats.

OBJECTIVE

To assess the ototoxic effects of topically applied oxiconazole and terbinafine by means of auditory brainstem responses in rats.

DESIGN

Nonrandomized, controlled trial.

SETTING

Tertiary referral centre.

MATERIAL AND METHODS

The experiment was performed in 36 mature male Wistar albino rats. The study was conducted on four groups of rats: 10 rats received 1% oxiconazole cream, 10 rats received 1% terbinafine cream, 8 rats had gentamicin solution (40 mg/mL), and 8 rats had saline solution. A total perforation was created on the left tympanic membrane. The agents used in the study were administered to the left middle ears of the animals twice daily through a transcanal route, in doses of 0.1 cc, for 10 days.

MAIN OUTCOME MEASURES

Auditory brainstem response thresholds were obtained before the treatment and 7 days after termination of the application.

RESULTS

The differences in pre- and posttreatment thresholds for all stimuli (click, 1000 Hz, 4000 Hz) in auditory brainstem responses were statistically significant in the oxiconazole, terbinafine, and gentamicin groups (p < .0125). When the saline and gentamicin groups were compared to the other groups, auditory brainstem response threshold findings for all stimuli after the treatment showed statistically significant differences (p < .05).

CONCLUSION

Oxiconazole and terbinafine showed ototoxic effects reflected by elevated auditory brainstem response thresholds at the speech frequencies after being topically applied to the middle ear of rats. Further studies are needed to determine whether these auditory brainstem response threshold shifts are permanent.