Introduction
ototoxic, tinnitus, Tinnitus, barotrauma, trauma
RINGING IN THE EAR, TINNITUS, TINNITUS
Tinnitus, often described as ringing in the ear, is a perception of a sound without corresponding external source. The condition is very common with prevalence rates of approximately 10% of the adult population in the United States reporting tinnitus in the past year [Tinnitus can occur in one or both ears and often arises as a consequence of acoustic trauma, barotrauma, or ototoxic drug exposure which may damage the cochlea. In animal models, excessive activation of the N-methyl-D-aspartic acid (NMDA) subtype of glutamate receptors at the level of the inner hair cell synapses with resulting deafferentation may be key in altering activity of the auditory nerve and generating subjective tinnitus [Gacyclidine is an NMDA-receptor antagonist [In a completed Phase 1/2 study in 35 patients with unilateral tinnitus [The initial clinical study evaluated patients with relatively acute tinnitus ranging from 1 to 6 months since onset based on the hypothesis that an NMDA receptor antagonist administered locally to the cochlea would be most effective in the acute period after onset and prior to tinnitus “centralization” [