Fexofenadine is a Non-sedating H1 Histamine Receptor Antagonist. Fexofenadine Hydrochloride, the Active Ingredient is A histamine h1-receptor Antagonist with the Chemical Name (±)-4-[1 Nylmethyl)-1-piperidinyl]-butyl]- Α, Α-dimethylhydroxy-4-benzeneacetic Acid Hydrochloride. Fexofenadine Hcl is the Hydrochloride Salt Form of Fexofenadine, a Carboxylated Metabolic Derivative Of terfenadine and Third Generation Selective histamine h1-receptor Antagonist with Antihistaminic and Non-sedative Effects. fexofenadine competitively Binds Peripheral H1-receptors, Thereby Stabilizing An Inactive Conformation of the Receptor. Consequently histamine binding and Activity as a Result of Mast-cell Degranulation Followed By the Release of Multiple Inflammatory Mediators, such as Interleukins, Prostaglandin and Leukotriene Precursors, is Blocked, Thereby Preventing the Triggering of Pro-inflammatory Pathways.