Norfenefrine, also known as meta-octopamine or norphenylephrine and sold under the brand name Novadral among others, is a sympathomimetic medication which is used in the treatment of hypotension. It is a phenolic phenethylamine present primarily as the hydrochloride salt for pharmaceutical use; the molecule contains a primary aliphatic amine and a meta-phenolic substituent that confer water solubility and receptor selectivity. Pharmacologically it acts predominantly as an alpha adrenergic agonist producing peripheral vasoconstriction and increased systemic vascular resistance, with limited beta activity. Onset is rapid after intravenous administration and duration of action is short due to extensive metabolism by monoamine oxidase and other hepatic pathways; renal excretion clears polar metabolites. Typical physical characteristics are a white to off-white crystalline powder, highly soluble in water, mildly soluble in lower alcohols, and stable under recommended storage conditions with appropriate protection from moisture and light. Analytical control is performed by validated HPLC or LC-MS methods for assay and related substances, and by Karl Fischer titration for water content.
Parent: Norphenylephrine
Parent: Norphenylephrine/ Norphenylephrine Hydrochloride
Typical quality control specifications used by manufacturers and contract laboratories for norphenylephrine hydrochloride include an assay on the dried basis of approximately 98.0 to 102.0 percent by HPLC and limits for related substances to control process and degradation impurities; commonly accepted example limits are: any single related compound not greater than 0.5 percent w by w, and total impurities not greater than 2.0 percent w by w. Known related compounds and degradants monitored by analytical methods include positional isomers such as para- and ortho-octopamine, ring-substituted phenols, deaminated or dehydroxylated products, and small amounts of N-oxidized species; typical levels for these related compounds when material is within specification are at trace to subpercent amounts. Additional controls include residual solvents within ICH Q3C limits (for example methanol limited to 3000 ppm or lower depending on process), heavy metals below 20 ppm, and water content controlled typically to less than 5.0 percent by Karl Fischer.
Norphenylephrine hydrochloride is used to treat acute hypotension by producing peripheral vasoconstriction and raising systemic vascular resistance; it is administered when rapid blood pressure support is required, commonly by parenteral routes in clinical settings.
Patients with severe hypertension, untreated narrow angle glaucoma, pheochromocytoma, severe coronary artery disease, or known hypersensitivity to sympathomimetic amines should avoid norphenylephrine; it should be used with caution and under medical supervision in patients with hyperthyroidism, diabetes, or on monoamine oxidase inhibitors.
Norphenylephrine increases blood pressure primarily through activation of alpha adrenergic receptors on vascular smooth muscle, causing vasoconstriction which raises systemic vascular resistance and therefore increases arterial blood pressure; reflex bradycardia may occur secondary to the rise in blood pressure.
Norphenylephrine is marketed under several trade names in various regions, including Novadral among others, and may also be available under generic designations as norfenefrine or norphenylephrine hydrochloride depending on local regulatory approvals.
