Lidocaine: neurobiological targets and effects on the auditory system

Lidocaine, a local anesthetic and anti-arrhythmic agent, is also known both as a tinnitus- and as a pain-suppressing drug. The sites of action in tinnitus suppression are in the cochlea as well as in the central auditory nervous system. In the present study, audiological and brain imaging studies in humans were used to identify the anatomical structure where lidocaine has its action on tinnitus. Molecular studies were used to elucidate the action of lidocaine on the cellular level. Various ion channels and receptors (e.g. voltage-gated Na(+), K(+) and Ca(2+) channels, glutamate, GABA, glycine and vanilloid receptors), found in the auditory system and possibly connected to tinnitus, are affected by lidocaine. Identification of molecular structures involved in expression of neuroplasticity in the auditory system in tinnitus and modeling the binding sites of local anesthetics could lead to the design of subtype-specific inhibitors that could provide new pharmacological targets for treatment.