Ginkgo biloba may help tinnitus, but needs further investigation

Question Is ginkgo biloba an effective treatment for tinnitus?

Synopsis Ginkgo biloba has a variety of physiological effects, some good and some bad, and has been advocated for the treatment of dementia, intermittent claudication, and a host of other conditions. The authors of this thorough systematic review did a careful review of the literature and identified five randomised controlled trials, of which four had been published. They varied in quality; the Jadad scores were 0, 2, 4, and 5 for the four published studies, on a scale where 5 is best. Three studies included approximately 100 patients; the study with the weakest methodology had the most patients (n = 259); and the unpublished study included 60 patients. Most of the enrolled patients had chronic tinnitus for one year or longer. Four of the studies showed a clinically significant benefit in the ginkgo group over the control group. The one negative study used a smaller dose than the studies showing benefit (29.2 mg daily v 120-160 mg daily). Outcomes and study designs were too different for results to be combined, so the outcomes are reported qualitatively. A more recent randomised trial (BMJ 2001;322: 7311154618) did not show any benefit with a 50 mg dose, so the jury is still out.

Bottom line This systematic review provides cautious support for a trial of ginkgo biloba 120-160 mg daily in patients with chronic tinnitus. A large, well designed trial of a 50 mg dose that was not included in this systematic review failed to show a benefit.

Level of evidence 1a (see www.infopoems.com/resources/levels.html); systematic review (with homogeneity) of randomised controlled studies.