Objective: Tinnitus is an extremely prevalent condition that currently has no satisfactory clinical treatment. Development of therapy has been hampered by the diversity of underlying conditions that give rise to the symptom of tinnitus. A drug that has multiple actions may have an improved chance of being effective. One such drug is lamotrigine, a recently developed antiepileptic agent that has both glutamate release inhibition and sodium channel antagonist activity.
Study design: Lamotrigine was evaluated in a double-blind, placebo-controlled, crossover clinical trial. Patients initially were tested with an intravenous infusion of lidocaine (10 mg/mL) to a maximum of 100 mg or until a reduction in tinnitus. Lamotrigine or placebo tablets were taken once daily (25 mg) for 2 weeks, 50 mg for 2 weeks, and 100 mg for 4 weeks.
Setting: Patients were chosen from among volunteers from the tinnitus clinic in the local hospital without reference to underlying pathology.
Patients: Those patients whose tinnitus had been present for less than 6 months or whose tinnitus was likely to vary spontaneously were excluded.
Interventions: Perceived intensity and intrusiveness of tinnitus was assessed before entry onto the trial and at 4-week intervals throughout the trial.
Main outcome measures: Assessment comprised questionnaires, visual analog scales, and a battery of audiologic measurements.
Results: There was no correlation between the response to lidocaine and the response to lamotrigine. There was good agreement between the questionnaires and visual analog scales in the reporting of perceived changes; however, this was not reflected as changes in the audiologic tests.
Conclusions: Of the 31 participants who completed the trial, questionnaires indicated that lamotrigine was effective in a very few of these persons.