Preliminary results of a new delivery system for gentamicin to the inner ear in patients with Meniere's disease.

Intratympanic gentamicin therapy has gained some clinical popularity in the treatment of vertigo associated with Meniere's disease. This therapeutic modality offers some advantages over traditional surgical treatment. The vestibulotoxic effect of gentamicin is well documented, but there is no general agreement about the dose needed to control vertigo attacks without affecting hearing. In the current preliminary study 27 patients with Meniere's disease refractory to medical management were treated by small doses of gentamicin delivered via microcatheter in the round window niche and administered by an electronic micropump. The patients received a total dose of 0.24-90 mg. The effect on vestibular symptoms resulted in the cessation of vertigo in the 22 patients, control of drop attacks in 4 of 6, and release of aural pressure and fullness in 2 of 4. Significant hearing loss (anacusis) occurred in six patients, slightly related to the flow rate in the pump setting. Different explanations for the loss of hearing are presented. The new delivery system for gentamicin appears to be effective in controlling vertigo, but with an unacceptable negative effect on hearing. The effectiveness and the safety of this new delivery system must be investigated further in controlled studies. However, it opens up the possibility of future novel ways of treating inner ear diseases, such as sudden deafness and tinnitus, as well as for the protection, repair, and regeneration of inner ear sensory cell function in damage due to aging, noise, toxic substances, immune reactions, etc.