Effect of treatment with Ginkgo biloba extract EGb 761 (oral) on unilateral idiopathic sudden hearing loss in a prospective randomized double-blind study of 106 outpatients

Objective: Test of dose-response relationship for Ginkgo biloba extract EGb 761 (oral) in outpatients with acute idiopathic sudden sensorineural heari ng loss (ISSHL) of at least 15 dB at one frequency within the speech range occurring less than 10 days before study inclusion. Design: Multicentre, ra ndomized, double-blind phase III study comparing dosages of 120 mg twice da ily and 12 mg twice daily over 8 weeks. Main endpoint: Recovery (in dB) of the auditory threshold from the initial measurement to the value on the las t day of treatment, averaged over those frequencies from 0.25, 0.5, 1, 2, a nd 3 kHz for which the initial hearing loss amounted to 15 dB or more compa red to the level on the opposite side. Patients: 106 patients with an avera ge age of 44 +/- 16 years and with hearing loss at affected frequencies 26 dB +/- 9 dB included between December 1995 and July 1997. Results: Large ma jorities of both treatment groups recovered completely. In exploratory anal yses of the 96 patients included according to the protocol, patients given the higher dose had less risk of not recovering well (less than or equal to 10 dB residual hearing loss) (one-sided Fisher test: P = 0.0061), especial ly if they had no tinnitus (n = 44, P = 0.00702). Conclusion: A higher dosa ge of EGb 761 (oral) appears to speed up and secure the recovery of ISSHL p atients, with a good chance that they will recover completely, even with li ttle treatment. This was already observed after one week of treatment. We f ind it justified to treat patients who have unilateral ISSHL of less than 7 5 dB and neither tinnitus nor vertigo with 120 mg oral EGb 761 twice daily.