Metaraminol, previously sold under the brand name Aramine among others and also known as metaradrine, is a

stereoisomer In stereochemistry, stereoisomerism, or spatial isomerism, is a form of isomerism in which molecules have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in ...

of ''meta''-hydroxynorephedrine (3,β-dihydroxyamphetamine), is a potent

sympathomimetic amine Sympathomimetic drugs (also known as adrenergic drugs and adrenergic amines) are stimulant compounds which mimic the effects of endogenous agonists of the sympathetic nervous system. Examples of sympathomimetic effects include increases in heart ...

used in the prevention and treatment of

hypotension Hypotension is low blood pressure. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. Blood pressure is indicated by two numbers, the systolic blood pressure (the top number) and the dias ...

, particularly as a complication of

anesthesia Anesthesia is a state of controlled, temporary loss of sensation or awareness that is induced for medical or veterinary purposes. It may include some or all of analgesia (relief from or prevention of pain), paralysis (muscle relaxation), ...

. It is an α₁-adrenergic receptor

agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...

with some β effect. It is currently sold in its generic form by Slayback Pharma.

Pharmacology and use as a vasopressor

Metaraminol is given

intravenously Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrie ...

as either a bolus (often 0.5-1mg doses) or as an infusion, usually via peripheral intravenous access. Metaraminol is commonly available as 10mg in 1mL, that requires dilution prior to administration (often made up to a 0.5mg/mL solution), however pre-prepared syringes of metaraminol for bolus use for hypotension are also commonly available. Metaraminol prefilledsyringe

Pharmacodynamics

The dominant mechanism for the vasopressor action of metaraminol is indirect, with metaraminol displacing

noradrenaline Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad'', ...

from neuronal vesicles in order for the noradrenaline to exert its vasopressor action. Metaraminol at higher doses may have direct

alpha-adrenergic agonist The adrenergic receptors or adrenoceptors are a class of G protein-coupled receptors that are targets of many catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) produced by the body, but also many medications like beta ...

and beta-1 adrenergic agonist effects. However at doses common in clinical practice, the indirect

alpha-1 adrenergic 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-adrenergic ...

effects predominate, such that

reflex bradycardia Reflex bradycardia is a bradycardia (decrease in heart rate) in response to the baroreceptor reflex, one of the body's homeostatic mechanisms for preventing abnormal increases in blood pressure. In the presence of high mean arterial pressure, the ...

is a common side-effect.

Research

Metaraminol is also used in the treatment of

priapism Priapism is a condition in which a penis remains erect for hours in the absence of stimulation or after stimulation has ended. There are three types: ischemic (low-flow), nonischemic (high-flow), and recurrent ischemic (intermittent). Most cases ...

References

External links

* * Alpha-1 adrenergic receptor agonists Beta-adrenergic agonists Cardiac stimulants Phenylethanolamines Phenols Substituted amphetamines {{cardiovascular-drug-stub