Vestibular damage from chlorhexidine in guinea pigs

In the early 1970s the suspicion arose that chlorhexidine, a disinfectant extensively used for preoperative skin disinfection, was ototoxic if introduced into the middle ear cavity. It has previously been shown by the author that chlorhexidine causes damage to the organ of Corti of guinea pigs when introduced into the tympanic cavity. In the present study the toxic effect of chlorhexidine on the vestibular part of the inner ear is investigated. Middle ears of guinea pigs were exposed to chlorhexidine in two different concentrations in two different solvents. The duration of exposure was varied and the animals were sacrificed and examined at various periods. Damaged neuroepithelia were seen in most of the animals. The extent of damage was related to the concentration of chlorhexidine, to the duration of exposure and to the time lapse after exposure.