title: Local anaesthetics and tinnitus. Proposed peripheral mechanism of action of lidocaine.
abstract: To elucidate the question whether lidocaine reduces tinnitus by a central or by a peripheral mechanism of action, its effect on tinnitus was compared with that of QX-572, a quaternary ammonium derivative of lidocaine which does not readily penetrate the blood-brain barrier. The results of experimental as well as clinical investigations indicate that the effects of lidocaine and QX-572 on tinnitus are mediated by a peripheral mechanism possibly related to their accumulation on inner ear melanin.
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002621:Chemistry; D004311:Double-Blind Method; D007758:Ear, Inner / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000627:therapeutic use; D008543:Melanins / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014012:Tinnitus / Q000188:drug therapy / Q000378:metabolism*
chemical_list: D008543:Melanins; D008012:Lidocaine; C006110:carcainium chloride