[10][11] As a medication, it is used to treat several conditions, including anaphylaxis, cardiac arrest, asthma, and superficial bleeding.

[8] Epinephrine is normally produced by both the adrenal glands and a small number of neurons in the brain, where it acts as a neurotransmitter.

[24] Epinephrine is used to treat a number of conditions, including cardiac arrest, anaphylaxis, and superficial bleeding.

[25] It has been used historically for bronchospasm and low blood sugar, but newer treatments for these that are selective for β2 adrenoceptors, such as salbutamol, are preferred.

[citation needed] While epinephrine is often used to treat cardiac arrest, it has not been shown to improve long-term survival or mental function after recovery.

[37] In August 2024, an epinephrine nasal spray (brand name Neffy) was approved in the United States for the emergency treatment of allergic reactions (type I), including those that are life-threatening (anaphylaxis), in people who weigh at least 30 kilograms (66 lb).

[43] Racemic adrenaline works by stimulating the alpha-adrenergic receptors in the airway, with resultant mucosal vasoconstriction and decreased subglottic edema, and by stimulating the β adrenergic receptors, with resultant relaxation of the bronchial smooth muscle.

[42] There is a lack of consensus as to whether inhaled nebulized epinephrine is beneficial in the treatment of bronchiolitis, with most guidelines recommending against its use.

[48] Adverse reactions to adrenaline include palpitations, tachycardia, arrhythmia, anxiety, panic attack, headache, anorexia, tremor, hypertension, and acute pulmonary edema.

[medical citation needed] The use of epinephrine based eye-drops, commonly used to treat glaucoma, may also lead to a buildup of adrenochrome pigments in the conjunctiva, iris, lens, and retina.

Together, these effects increase blood glucose and fatty acids, providing substrates for energy production within cells throughout the body.

It appears that epinephrine may improve macrocirculation at the expense of the capillary beds where perfusion takes place.

[57] American ophthalmologist William H. Bates discovered adrenaline's usage for eye surgeries prior to 20 April 1896.

[58] Japanese chemist Jōkichi Takamine and his assistant Keizo Uenaka independently discovered adrenaline in 1900.

[62][63][64] Epinephrine is sold under various brand names including Asthmanefrin, Micronefrin, Neffy, Nephron, VapoNefrin, and Primatene Mist, among others.

There is an epinephrine metered-dose inhaler sold over the counter in the United States to relieve bronchial asthma.