Adrenalone is an adrenergic agonist used as a topical vasoconstrictor and hemostatic. Formerly, it was also used to prolong the action of local anesthetics. It is the ketone form of epinephrine (adrenaline). Contrary to epinephrine, adrenalone mainly acts on alpha-1 adrenergic receptors, but has little affinity for beta receptors. The drug is largely obsolete, being superseded by other hemostatics such as thrombin, fibrinogen, and vasopressin analogues.