Guanfacine Hydrochloride is the hydrochloride salt form of guanfacine, a centrally acting alpha-2 adrenergic agonist with antihypertensive activity. Alpha-2 receptor stimulation by guanfacine hydrochloride results in a decreased sympathetic outflow from the vasomotor center to the heart, kidneys, and peripheral vasculature. This leads to a decrease in heart rate and peripheral vascular resistance.