What is alpha adrenergic agonist

Drug or substance that acts as a neurotransmitter to activate certain epi-nephrine (also called adrenaline) receptors in smooth muscle tissue, increasing the amounts of epinephrine that can bind to these receptors. Epi-nephrine, like dopamine, belongs to the cate-cholamine chemical family. Among its effects, it raises blood pressure, opens the airways, and increases blood flow to the muscles to allow them to increase activity such as is necessary during exercise. Alpha-adrenergic agonists are sometimes used to treat erectile dysfunction and orthostatic hypotension.