[Study protocol of the monocentric prospective randomized placebo-controlled double-blind phase II study to explore the protective effects of the ginkgo biloba extract EGb 761® from temporary noise-induced hearing loss].

backgroundHearing loss is frequently induced by occupational noise exposure and leads to rising hearing thresholds as well as reduced otoacoustic emissions (OAE), mostly caused by metabolic hair cell decompensation.

objectivePrimary endpoint is the increase in average pure tone thresholds after noise exposure, secondary endpoints are loss of distortion product and click-evoked OAE as well as reduction of their contralateral suppression. PARTICIPANTS AND

methodsThe present study design describes the verification of the anti-oxidant and neuroprotective properties of EGb 761® by evaluation of cochlear protection from noise impact as well as its safety and tolerance in 202 healthy male participants distributed equally to verum and placebo groups in a double-blind manner. Participants were assessed, medicated, exposed to noise, and then examined at timepoints up to 10 min and 4 weeks thereafter.

conclusionThis summary of the verification study protocol highlights the complexity of diligent and precise planning according to the European Medicines Agency criteria for controlled trials (EudraCT). Key points are the intervention rationale, definitions of in- and exclusion criteria, estimation of subject numbers, and examination method setting in terms of optimum endpoint description.