I.V. ropivacaine compared with lidocaine for the treatment of tinnitus.

Author(s): Kallio H, Niskanen ML, Havia M, Neuvonen PJ, Rosenberg PH, Kentala E

Affiliation(s): Department of Anaesthesiology and Intensive Care Medicine, Eye Hospital, Helsinki University Central Hospital-Anaesthesia, Haartmanstr. 4, PO Box 220, Helsinki 00029, HUS, Finland. helena.kallio@hus.fi

Publication date & source: 2008-08, Br J Anaesth., 101(2):261-5. Epub 2008 Jun 2.

Publication type: Comparative Study; Randomized Controlled Trial; Research Support, Non-U.S. Gov't

BACKGROUND: I.V. lidocaine has been used to ameliorate tinnitus, but in general its effect has been limited. The longer acting local anaesthetic ropivacaine may be more effective. METHODS: A total of 19 randomized, double-blind, cross-over study patients suffering from chronic tinnitus were given a 30 min i.v. infusion of ropivacaine or lidocaine 1.5 mg kg(-1) at an interval of 2-3 months. The intensity of tinnitus was evaluated on tinnitus handicap inventory (THI) scale and on the visual analogue scale (VAS). Plasma ropivacaine and lidocaine concentrations were determined. RESULTS: In both treatments, the infusion decreased the VAS score significantly. At the end of infusion, a > or =50% reduction in VAS score was observed in five patients by ropivacaine and in one patient by lidocaine, but this effect was sustained for 1 h only in three patients. However, the THI scores did not differ significantly within or between treatments. On the post-infusion day, three patients after ropivacaine and five after lidocaine treatment had > or =30% improvement in the THI score. Four weeks later, one patient after ropivacaine and two after lidocaine had a > or =30% reduction in the THI score. One patient developed seizures soon after ropivacaine infusion from which he recovered uneventfully. His plasma concentration of ropivacaine was 1817 ng ml(-1). The highest individual ropivacaine and lidocaine concentrations were 3483 and 1680 ng ml(-1), respectively. CONCLUSIONS: Temporary clinically significant alleviation of tinnitus was observed only in a few individuals after both i.v. ropivacaine and lidocaine. The toxicity of ropivacaine limits its usefulness.