Also called adrenaline, C9H13NO3. A catecholamine hormone (sympathomimetic monoamine derived from the amino acids, phenylalanine and tyrosine) secreted (with noradrenaline (norepinephrine)) by the medulla of the adrenal gland, and by neurons of the sympathetic nervous system. It is a stimulant of the nervous system.
The effects of high levels of this hormone are the "fight or flight" response - increased heart function, elevation in blood sugar levels by the increased hydrolysis of glycogen to glucose, cutaneous vasoconstriction making the skin pale and increasing the blood supply to major muscles, and raising of hairs on the neck.
Epinephrine is used medicinally as a stimulant in cardiac arrest, as a vasoconstrictor in anaphylactic shock, as a bronchodilator and antispasmodic in acute bronchial asthma, to lower intra-ocular pressure in the treatment of glaucoma and to treat acute chloroquine poisoning. Adverse reactions can be palpitations, sinus tachycardia, anxiety, headache, tremor, fever and hypertension; with an overdose causing severe pulmonary arterial hypertension and the risk of acute pulmonary oedema.