[Topical ototoxicity: review over a 6-year period]

Over a six-year period, 6 cases of local toxicity produced by gentamicin and dexamethasone ear drops were observed in Sant Pau Hospital, Barcelona. No cases due to neomycin or polymixin B were seen. All patients consulted for dizziness. Audiometric and vestibular examination revealed only involvement of the vestibular labyrinth and recovery was spontaneous. Most cases occurred during prolonged treatment without medical control and patients had extensive tympanic perforation or suppuration had ceased. In contrast with findings in animal studies, the risk of topical toxicity in humans is limited and avoidable if the necessary precautions are taken with ear-drop prescriptions.