Overview
Vasopressin (Vasostrict) is an FDA-approved synthetic form of the endogenous nonapeptide antidiuretic hormone (ADH) produced by the hypothalamus. It is used intravenously to increase blood pressure in adults with vasodilatory shock who remain hypotensive despite fluid resuscitation and catecholamines. It also has roles in the management of diabetes insipidus and gastrointestinal variceal bleeding.
Mechanism of action
Vasopressin exerts its vasopressor effects primarily through V1a receptors on vascular smooth muscle. V1a receptor activation is coupled to Gq/11 proteins, stimulating phospholipase C to generate IP3 and diacylglycerol, leading to intracellular calcium release and smooth muscle contraction. This increases peripheral vascular resistance and raises mean arterial pressure without direct cardiac stimulation. In vasodilatory shock (including septic shock), endogenous vasopressin is depleted; exogenous supplementation restores vascular tone and may reduce catecholamine requirements. V2 receptor activation on renal collecting duct cells promotes water reabsorption via aquaporin-2 insertion, mediating the antidiuretic effect. Vasopressin also activates V1b receptors in the anterior pituitary (modulating ACTH release) and oxytocin receptors, and exerts procoagulant activity via factor VIII and von Willebrand factor release.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| vasodilatory shock (septic, post-cardiac surgery) | intravenous | 0.01–0.03 units/min | continuous IV infusion, titrate to MAP target | Fixed dose adjunct: 0.03 units/min added to catecholamine. Do not titrate vasopressin in place of titrating norepinephrine. Doses above 0.04 units/min associated with myocardial ischemia and bowel necrosis. |
| diabetes insipidus | intramuscular | 5–10 units | every 8–12 hours as needed | For central DI: 5–10 units IM every 8–12 hours. Monitor serum sodium and urine osmolality. Desmopressin (DDAVP) is usually preferred for chronic DI management. |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
The VASST trial (778 patients with septic shock) compared vasopressin plus norepinephrine to norepinephrine alone and found no difference in 28-day mortality in the overall population, but showed a survival benefit in the less severe septic shock subgroup. FDA approved vasopressin (Vasostrict) in 2014 specifically for vasodilatory shock. The VANISH trial explored vasopressin vs. norepinephrine as first-line therapy in septic shock; vasopressin reduced renal replacement therapy use. Current sepsis guidelines recommend vasopressin as a second-line vasopressor adjunct to norepinephrine.
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Legal status
FDA-approved since 2014 as Vasostrict for vasodilatory shock. Administered by continuous intravenous infusion in an ICU setting with hemodynamic monitoring. Not a controlled substance. Compounded vasopressin preparations are also available from 503B outsourcing facilities.
Where to get it
Prescription required
Vasopressin is a prescription medication. Consult your healthcare provider or a licensed telehealth platform for access.