Ototoxicity of topical moxifloxacin in a chinchilla animal model.

Abstract

Ciprofloxacin is currently the only proven nonototoxic topical antibiotic. However, its widespread use has resulted in the emergence of antimicrobial resistance. There are also concerns that there is currently no safe alternative to ciprofloxacin for patients with a nonintact eardrum. We thus wished to evaluate whether a moxifloxacin solution is ototoxic when used topically in chinchilla ears in the presence of a pressure-equalizing tube (PET). A prospective, randomized, controlled trial was conducted in an animal model. Twenty chinchillas were included in this study. After bilateral insertion of PETs, four drops of a moxifloxacin solution were delivered twice daily for 7 days in the randomly assigned experimental ear. The control ear received an equal amount of a solution of Ringer's lactate. Distortion product otoacoustic emissions (DPOAE) were recorded at baseline (after PET insertion) and at days 1, 3, 7, 14, and 28 after treatment initiation. When baseline DPOAE measurements were compared with the final measurements at day 28, moxifloxacin caused a statistically significant (P < .05) hearing loss (HL) in the experimental ears for the frequencies between 3.7 and 15 kHz. There was no significant change in hearing in the control ears. This represents the first study on the ototoxicity of topical moxifloxacin. Our results demonstrate that moxifloxacin causes HL when used with a nonintact tympanic membrane in a chinchilla animal model.