Antihistamines such as azatadine appear to compete with histamine for histamine H1- receptor sites on effector cells. The antihistamines antagonize those pharmacological effects of histamine which are mediated through activation of H1- receptor sites and ther…

Ketotifen is a benzocycloheptathiophene derivative[A231204] with potent antihistaminic and mast cell stabilizing properties. It has a similar structure to some other first-generation antihistamines such as [cyproheptadine] and [azatadine].[A231204] Ketotif…