Also called adrenaline, epinephrine is a hormone produced by the adrenal medulla and released into the bloodstream in response to physical or mental stress, as from fear or injury. Epinephrine initiates many bodily responses, including the stimulation of heart action and an increase in blood pressure, metabolic rate, and blood glucose concentration. Chemically, epinephrine is a catecholamine, a monoamine produced only by the adrenal medulla, which is a part of adrenal glands, from the amino acids phenylalanine and tyrosine.
Epinephrine is used as a drug to treat cardiac arrest and other cardiac dysrhythmias resulting in diminished or absent cardiac output. Its actions are to increase peripheral resistance via a1receptor-dependent vasoconstriction and to increase cardiac output via its binding to ß1receptors. The usual ACLS concentration for injection is epinephrine 1:10,000.