Guanfacine hydrochloride, an anti-hypertensive agent, is a selective α2A-adrenoceptor agonist with Kd of 31 nM and displays 60-fold selectivity over α2B-adrenoceptors. IC50 Value: 31 nM(Kd) Target: Adrenergic Receptor Guanfacine is a sympatholytic. It is a selective α2A receptor agonist. These receptors are concentrated heavily in the prefrontal cortex and the locus coeruleus, with the potential to improve attention resulting from interaction with receptors in the former. Guanfacine lowers both systolic and diastolic blood pressure by activating the central nervous system α2A norepinephrine autoreceptors, which results in reduced peripheral sympathetic outflow and thus a reduction in peripheral sympathetic tone. From Wikipedia