Epinefriini

Epinefriini, also known as epinephrine or adrenaline, is a hormone and neurotransmitter in the catecholamine family. In humans, it is produced by the adrenal medulla and by certain neurons of the sympathetic nervous system. It is released during stress as part of the fight-or-flight response and acts on adrenergic receptors to modulate cardiovascular, respiratory, and metabolic functions.

Epinefriini acts by binding to alpha and beta adrenergic receptors, with prominent effects on beta1 and beta2 receptors in the heart and lungs and on alpha1 receptors in vascular smooth muscle. This produces increased heart rate and contractility, bronchodilation, vasoconstriction in skin and gut, and metabolic effects such as glycogenolysis and lipolysis. The net effect is rapid preparation for physical activity and maintenance of blood pressure during stress or danger.

Medical uses of epinefriini include treatment of anaphylaxis and severe allergic reactions, cardiac arrest, and certain cases of shock or asthma. It is also used as an additive in local anesthetics to prolong effect and reduce bleeding. Administration routes vary by indication and setting, including intramuscular injections (such as auto-injectors for emergencies) and intravenous dosing in clinical contexts; formulations exist for inhalation or local tissue use.

Pharmacokinetics and safety: Epinefriini is rapidly absorbed when given parenterally and has a short duration of action. It is metabolized mainly by catechol-O-methyltransferase and monoamine oxidase and excreted as metabolites. Common adverse effects include tachycardia, hypertension, tremor, anxiety, and potential arrhythmias; caution is advised in patients with cardiovascular disease or hypertension.

History: Epinefriini was isolated in 1901 by Jokichi Takamine and has since become a standard emergency and resuscitation drug as well as a cornerstone of allergy treatment.