<unk> armacodynamics<unk>  is a sympathomimetic drug, which means that it mimics the actions of epinephrine (commonly known as adrenaline) or norepinephrine.<unk>  selectively binds to alpha-1 receptors which cause blood vessels to constrict. Whereas pseudoephedrine causes both vasoconstriction and increase of mucociliary clearance through its nonspecific adrenergic activity,<unk> 's selective α-adrenergic agonism causes vasoconstriction alone, creating a difference in their methods of action.<unk> armacokinetics Oral<unk>  is extensively metabolized by monoamine oxidase, an enzyme that is present on the mitochondrial membrane of cells throughout the body. Compared to intravenous pseudoephedrine,<unk>  has a reduced and variable bioavailability; only up to 38%.
Phenylephrine
Prazosin
Terazosin
Acebutolol
Doxazosin
Oxymetazoline
Metergoline
Clonidine