Adrenalone is an adrenergic agonist used as a topical

vasoconstrictor Vasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vess ...

and

hemostatic An antihemorrhagic (antihæmorrhagic) agent is a substance that promotes hemostasis (stops bleeding). It may also be known as a hemostatic (also spelled haemostatic) agent. Antihemorrhagic agents used in medicine have various mechanisms of action: ...

. Formerly, it was also used to prolong the action of

local anesthetic A local anesthetic (LA) is a medication that causes absence of pain sensation. In the context of surgery, a local anesthetic creates an absence of pain in a specific location of the body without a loss of consciousness, as opposed to a general a ...

s. It is the ketone form of epinephrine (adrenaline). Contrary to epinephrine, adrenalone mainly acts on

alpha-1 adrenergic receptor alpha-1 (α1) adrenergic receptors are G protein-coupled receptors (GPCRs) associated with the Gq heterotrimeric G protein. α1-adrenergic receptors are subdivided into three highly homologous subtypes, i.e., α1A-, α1B-, and α1D-adrenerg ...

s, but has little affinity for beta receptors. The drug is largely obsolete, being superseded by other hemostatics such as

thrombin Thrombin (, ''fibrinogenase'', ''thrombase'', ''thrombofort'', ''topical'', ''thrombin-C'', ''tropostasin'', ''activated blood-coagulation factor II'', ''blood-coagulation factor IIa'', ''factor IIa'', ''E thrombin'', ''beta-thrombin'', ''gamma- ...

fibrinogen Fibrinogen (factor I) is a glycoprotein complex, produced in the liver, that circulates in the blood of all vertebrates. During tissue and vascular injury, it is converted enzymatically by thrombin to fibrin and then to a fibrin-based blood cl ...

, and

vasopressin analogue Vasopressin analogues are chemicals similar in function but not necessarily similar in structure to vasopressin (ADH), such as desmopressin. Desmopressin is administered as an oral spray to treat diseases where ADH is either not being produced in ...

Contraindications and interactions

Adrenalone does not stop bleeding from large blood vessels. It is not approved for systemic use. Combination with

antithrombotic An antithrombotic agent is a drug that reduces the formation of blood clots (thrombi).http://cancerweb.ncl.ac.uk/cgi-bin/omd?antithrombotic Antithrombotics can be used therapeutically for prevention ( primary prevention, secondary prevention) or ...

s is not useful because they contravene the action of adrenalone.

Side effects

Vasoconstriction by adrenalone may lead to local necrosis.

Pregnancy and lactation

Adrenalone passes into breast milk, but adverse effects are unlikely because of its very low systemic resorption.

Chemical properties

Adrenalone is a derivative of epinephrine, having the alcohol function replaced with a ketone. As a consequence, it is not optically active any more. Solubility in water,

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a ...

and

diethyl ether Diethyl ether, or simply ether, is an organic compound in the ether class with the formula , sometimes abbreviated as (see Pseudoelement symbols). It is a colourless, highly volatile, sweet-smelling ("ethereal odour"), extremely flammable li ...

is low. The substance is typically used in form of the

hydrochloride In chemistry, a hydrochloride is an acid salt resulting, or regarded as resulting, from the reaction of hydrochloric acid with an organic base (e.g. an amine). An alternative name is chlorhydrate, which comes from French. An archaic alternative n ...

, a white crystalline powder which tastes bitter and slightly acidic, and is soluble in water (1:8) and 94% ethanol (1:45). The melting point of the hydrochloride is .

Pharmacology

After local application, only traces of adrenalone are found in the blood, which is partly a consequence of the vasoconstriction caused by the drug via alpha-1 adrenergic receptors. In an (unspecified) pharmacological model, hypertensive (blood pressure increasing) action has been found to be about 0.5% that of epinephrine at equivalent plasma concentrations. Therefore, systemic effects are unlikely. Like epinephrine, adrenalone is metabolised by

catechol-O-methyl transferase Catechol-''O''-methyltransferase (COMT; ) is one of several enzymes that degrade catecholamines (neurotransmitters such as dopamine, epinephrine, and norepinephrine), catecholestrogens, and various drugs and substances having a catechol struct ...

(COMT), yielding 3O-methyladrenalone, which in turn is N-demethylized by monoamine oxidase (MAO). Alternatively, it can first undergo metabolization by MAO and then by COMT; in both cases, the resulting 3O-methyl-N-demethyladrenalone is conjugated to

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...

glucuronide A glucuronide, also known as glucuronoside, is any substance produced by linking glucuronic acid to another substance via a glycosidic bond. The glucuronides belong to the glycosides. Glucuronidation, the conversion of chemical compounds to glucu ...

and excreted by the kidney. No reduction to epinephrine has been observed ''in vivo''.

References

{{Antihemorrhagics Catecholamines Aromatic ketones