I have used antihistamines a few times and a few times they dropped my tinnitus. I remember especially after I combined it with melatonin and woke up the next day with lower T. I also remember not taking it with melatonin and it seemed to lower my T the next day but I don't remember it lowering it after that. I have heard others that have used anti-histamines to lower tinnitus. According to Wikipedia "Histamine release in the brain triggers secondary release of excitatory neurotransmitters such as glutamate and acetylcholine via stimulation of H1 receptors in the cerebral cortex." https://en.wikipedia.org/wiki/Antihistamine Is it possible that it has something to do with affecting glutamate levels? There may be another mechanism so if you know, please tell me.