Topical administration of Caroverine in somatic tinnitus treatment: proof-of-concept study.

This prospective study, which conformed with good clinical practice (GCP-conform), tested the concept that the topical transtympanic administration of the quinoxaline derivative Caroverine promises a new approach to the treatment of tinnitus. The rationale for the study is the hypothesis that tinnitus reflects sequelae of auditory neurotoxicity that can prevented and repaired by the neuroprotective and neuroregenerative activities of quinoxaline derivatives exhibited in previous preclinical tests. In a representative patient cohort, the probability of a long-lasting tinnitolytic effect of lipophilic eardrops containing 1% Caroverine as their active ingredient gained in significance, crossing from low-intensity levels to high-intensity levels of individual tinnitus sensations. These results encouraged us to design consequential GCP-conform phase 2 and phase 3 studies.