Alpha receptors Alpha-1 Predominantly expressed on vascular smooth muscle. Agonists cause increase in tone resulting in hypertension (and reflex bradycardia). Think phenylephrine. Antagonists have the opposite effect. Alpha-2 Expressed on presynaptic receptors. Agonist activity results in feedback inhibition of sympathetic outflow. Thus, a decrease in BP and bradycardia (dexmedetomidine or clonidine). Alpha Blockers Phenoxybenzamine Irreversible […]