Bromodiphenhydramine also known as bromazine, is an antihistamine and anticholinergic agent, which was used to under brand name ambordyl. Ambordyfor was indicated for the treatment of allergic symptoms, but that usage, was discontinued. It was shown, that bromodiphenhydramine competed with free histamine for binding at HA-receptor sites and lead to a reduction of the negative symptoms brought on by histamine HA-receptor binding.