Comparative Pharmacology
Head-to-head clinical analysis: LEVOPHED versus VASOSTRICT.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LEVOPHED versus VASOSTRICT.
LEVOPHED vs VASOSTRICT
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Norepinephrine acts predominantly on alpha-1 adrenergic receptors to cause vasoconstriction and increase blood pressure. It also has beta-1 adrenergic receptor agonist activity, resulting in positive inotropic effects on the heart.
Vasopressin is a synthetic analogue of the antidiuretic hormone (ADH) that acts on V1 receptors (vascular smooth muscle) to cause vasoconstriction, and on V2 receptors (renal collecting ducts) to increase water reabsorption. At high doses used in vasodilatory shock, it primarily increases systemic vascular resistance via V1 receptor activation.
Initial dose: 8-12 mcg/min intravenously, titrate to desired blood pressure; typical maintenance: 2-4 mcg/min IV continuous infusion.
0.01-0.03 units/min IV continuous infusion, titrate to effect. Maximum 0.1 units/min.
None Documented
None Documented
The terminal elimination half-life is approximately 2 minutes. The clinical effect is short-lived due to rapid reuptake and metabolism; continuous intravenous infusion is required for sustained effect.
Terminal elimination half-life is approximately 10–20 minutes, with clinical effect terminated rapidly by enzymatic degradation (catechol-O-methyltransferase and monoamine oxidase) in the liver and other tissues.
Norepinephrine is primarily metabolized in the liver and other tissues by catechol-O-methyltransferase (COMT) and monoamine oxidase (MAO). Less than 5% is excreted unchanged in urine. Metabolites are excreted renally (approximately 80-95% as normetanephrine, vanillylmandelic acid, and other conjugates).
Primarily renal (90–95% as inactive metabolites); minor biliary/fecal excretion (<5%).
Category C
Category C
Vasopressor
Vasopressor