Objective: To assess the effect of Ginkgo biloba and clonazepam, a γ-aminobutyric acid (GABA)-receptor agonist, upon tinnitus.
Methods: This was an open-label, randomised, crossover study. 27 men and 11 women (aged 16-80 (mean 58)) with tinnitus for more than 2 months were enrolled. Participants were randomised to either clonazepam or G biloba for the first 3 weeks. For the next 2 weeks of washout no medication was taken. For the final 3 weeks, subjects were given the other drug. The initial dose of clonazepam and G biloba was one tablet daily (clonazepam 0.5 mg; G biloba 40 mg). Subjects were instructed to increase the dose by one tablet every 3 days to a maximum of four tablets daily until they perceived a satisfactory decrease in tinnitus loudness or intolerable side effects. Tinnitus was assessed with pitch and loudness matching, tinnitus handicap inventory, and visual analogue scales of loudness, duration and annoyance.
Results: Comparing before and after each drug, clonazepam significantly improved tinnitus loudness (74% of subjects), duration (63%), annoyance (79%), and tinnitus handicap inventory score (61%), whereas the G biloba showed no significant differences on any of these measures.
Conclusion: Clonazepam is effective in treating tinnitus; G biloba is ineffective.