Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1   Pharmacodynamic properties

Pharmacotherapeutic group: Cardiac stimulants excl. cardiac glycosides - Adrenergic and dopaminergic agents – Adrenaline, ATC-code: C01CA24

Adrenaline is the natural active sympathomimetic hormone from the adrenal medulla. It stimulates both the α- and β-adrenergic receptors. Adrenaline is the first choice for emergency treatment of severe allergic reactions and idiopathic or exercised-induced anaphylaxis.

Adrenaline has a potent vasoconstrictive effect through its α-adrenergic stimulation. This effect counteracts the vasodilatation and increased vascular perfusion, leading to low intravascular flow and hypotension, which are the main pharmacotoxicological effects in the anaphylactic shock.

By stimulating β-receptors in the lungs, adrenaline produces a potent bronchodilator effect with relief of wheezing and dyspnea. Adrenaline also relieves pruritus, urticaria and angioedema associated to anaphylaxis.

Pharmacokinetic Properties

5.2   Pharmacokinetic properties

Circulating adrenaline is metabolized in the liver and other tissues by the enzymes COMT and MAO.
Inactive metabolites are excreted in the urine.
The half-life of adrenaline in plasma is about 2 to 3 minutes. However, when adrenaline is injected subcutaneously or intramuscularly the absorption is retarded by local vasoconstriction and thus the effects can last longer than as predicted by half-life. Massage around the injection site is advised to accelerate absorption.