Clinical experience with caroverine in inner ear diseases.

The glutamatergic synapses between the cochlear inner hair cells and their afferent neurons seem to be mostly involved in the pathophysiology of the cochlea. Glutamatergic neurotoxicity is characterized by a mitochondrial overproduction of free oxygen radicals damaging lipid membranes and DNA structures of the postsynaptic neuron followed by the clinical symptoms of hearing loss and tinnitus. In preclinical tests, quinoxaline derivatives antagonized these deleterious consequences of too high an amount of free radicals. Therefore the clinically available quinoxaline dione caroverine provides a new approach to a successful treatment of tinnitus, sudden hearing loss and speech discrimination disorders in presbyacusis. The results of corresponding clinical trials are presented.