Active ingredient: Metaraminol - Brands, Medical Use, Clinical Data

Brands, Medical Use, Clinical Data

Drug Category

• Adrenergic Agents
• Adrenergic alpha-Agonists
• Sympathomimetics
• Vasoconstrictor Agents

Dosage Forms

• Intramuscular injection
• Intravenous injection

Brands / Synonyms

Aramine; Hydroxynorephedrine; Icoral B; L-Metaraminol; M-Hydroxy Norephedrine; M-Hydroxyphenylpropanolamine; M-Hydroxypropadrine; Metaradrine; Metaraminol Bitartrate; Metaraminolum [Inn-Latin]; Metaraminolum [Latin]; Pressonex; Pressorol

Indications

For the treatment and prevention of hypotension due to hemorrhage, spinal anesthesia, and shock associated with brain damage

Pharmacology

Metaraminol is a potent sympathomimetic amine that increases both systolic and diastolic blood pressure. Metaraminol is indicated for prevention and treatment of the acute hypotensive state occurring with spinal anesthesia. It is also indicated as adjunctive treatment of hypotension due to hemorrhage, reactions to medications, surgical complications, and shock associated with brain damage due to trauma or tumor. Metaraminol acts on both α1-adrenergic receptors but appears to have no effect on β-adrenergic receptors. It acts by increasing the force of the heart's pumping action as well as constricting peripheral blood vessels.

Mechanism of Action

Metaraminol acts through peripheral vasoconstriction by acting as a pure alpha-1 adrenergic receptor agonist, consequently increasing systemic blood pressure (both systolic & diastolic). Its effect is thought to be associated with the inhibition of adenyl cyclase which leads to an inhibition of the production of cAMP. Another effect of Metaraminol is that it releases norepinephrine from its storage sites indirectly.

Absorption

The effect starts 1-2 min after IV injection, 10 min after IM injection, 5-20 min after subcutaneous injection.

Toxicity

LD₅₀=240 mg/kg (rat, oral); LD₅₀=99 mg/kg (mouse, oral)

Biotrnasformation / Drug Metabolism

Hepatic

Contraindications

Use of ARAMINE with cyclopropane or halothane anesthesia should be avoided, unless clinical circumstances demand such use.

Hypersensitivity to any component of this product, including sulfites.

Drug Interactions

ARAMINE should be used with caution in digitalized patients, since the combination of digitalis and sympathomimetic amines may cause ectopic arrhythmias.

Monoamine oxidase inhibitors or tricyclic antidepressants may potentiate the action of sympathomimetic amines. Therefore, when initiating pressor therapy in patients receiving these drugs, the initial dose should be small and given with caution.