Ototoxic Effect of Iodine Disinfectants

Abstract

It had been suggested that disinfectants which could trickle into the middle ear through a perforated drum during the skin sterilization preceding otosurgery might cause inner ear damage resulting in deafness. In animal experiments it has been shown that chlorhexidine, benzethonium- and benzalkonium chloride, when introduced into the tympanic cavity of guinea pigs, will cause rather extensive damage to the neuroepithelial receptors of the inner ear. In the present study, iodine, frequently used for skin disinfection, has been investigated as regards ototoxicity by locally exposing the middle ear in guinea pigs. The duration of exposure was 10, 30, or 60 min. The animals were sacrificed 2 weeks later and the organs of Corti and neuroepithelial receptors of the vestibular part of the inner ear were studied as surface preparations in phase-contrast microscopy. It was found that slight damage had occurred in the basal parts of the organ of Corti of those ears exposed to iodine or iodophor in 70% alcohol for 60 or 30 min and damage to the vestibular receptors was observed in ears exposed to iodophor in 70% alcohol for 60 min. In ears exposed to iodine or iodophor in aqua dest., no damage to the inner ear sensory epithelia was revealed.

Ototoxicity of Different Concentrations Povidone-Iodine Solution Applied to the Middle Ear Cavity of Rats

“…They concluded that the age of the animals influenced the outcome of the ototoxicity experiment and povidone-iodine preparations in the infants should be used with caution emphasizing that full strength povidone scrub solution should not be used for otologic surgery. A few reported studies about these products' vestibular ototoxicity and the evaluation of vestibular damage mainly based on description of histological findings, which is not an objective measurement of vestibular end organ function [16,18]. The potential ototoxicity of iodine disinfectants has also previously been studied.…”

“…During the past 30 years, relatively small numbers of studies have been directed to the potential ototoxicity of these commonly used antimicrobial agents [16][17][18]. Most of these investigations referred the damage to the cochlear part of the inner ear, assessing it by pathological cochlear histology and/or abnormal responses in different electrophysiological tests.…”

Deafness after Treatment with Ear Drops Containing Neomycin, Gramicidin and Dexamethasone

“…Aursnes [8] reported no inner car damage after intratympanic injection of aqueous io dine solutions. The same substances dis solved in 70% ethyl alcohol, however, were highly ototoxic.…”

Topical Antiseptics in Ear Surgeries and Ototoxicity Effect: Review Article.

“…It was found that slight damage had occurred in the basal parts of the organ of Corti of those ears exposed to iodine or iodophor in 70% alcohol for 60 or 30 min and damage to the vestibular receptors was observed in ears exposed to iodophor in 70% alcohol for 60 min. on the other hand,chlorhexidine caused extensive damage to the neuroepithelial receptors of the inner ear (20).…”