Vasopressin
Vasopressin
Brand names:Vasostrict, Pitressin (historical)
A synthetic analog of antidiuretic hormone (ADH) used as a second-line vasopressor in septic shock, refractory shock, and diabetes insipidus. Vasopressin acts on V1 vascular receptors to produce vasoconstriction independent of the adrenergic pathway, making it particularly useful in catecholamine-refractory hypotension and as an adjunct to norepinephrine to reduce catecholamine requirements.
Pharmacology and Actions
Acts on V1 receptors in vascular smooth muscle to cause vasoconstriction through a non-adrenergic mechanism (phospholipase C activation, intracellular calcium release). V2 receptor activation in renal collecting ducts increases water reabsorption (antidiuretic effect). The non-adrenergic mechanism preserves vasoconstrictive efficacy in acidotic and catecholamine-resistant states where alpha-adrenergic agents lose effect. Less tachycardia than norepinephrine or epinephrine.
Indications
- Septic shock as adjunct to norepinephrine to reduce catecholamine dose and improve hemodynamics
- Catecholamine-refractory distributive shock
- Cardiac arrest (historical ACLS indication; removed from current AHA guidelines in 2015 but still used in some protocols)
- Central diabetes insipidus
- Esophageal variceal bleeding (off-label, largely replaced by octreotide)
Absolute Contraindications
- Known hypersensitivity to vasopressin
- Chronic nephritis with elevated nitrogen retention (until levels stabilize)
- No absolute contraindications in life-threatening shock
Precautions and Side Effects
Mesenteric ischemia and digital ischemia at higher doses or in patients with vascular disease. Hyponatremia from excess water retention with prolonged infusion. Cardiac ischemia (coronary vasoconstriction). Bronchoconstriction. Skin necrosis at IV site if extravasation occurs. Fluid retention. Generally fewer arrhythmias than catecholamines.
Adult Dosing
Pediatric Dosing
Septic shock: 0.0002 to 0.002 units/kg/min continuous infusion. Pediatric data limited; consultation with pediatric critical care recommended.
Pharmacokinetics
Peak Effect: 15 minutes
Duration: Plasma half-life 10 to 35 minutes
Storage and Handling
Refrigerate at 2 to 8 degrees C. Pre-mixed solutions (20 units in 100 mL NS or 40 units in 100 mL NS) increasingly available; vials of 20 units/mL for dilution also stocked. Stable at room temperature 24 to 48 hours once diluted. Discoloration suggests degradation.
Reconstitution:
Vials of 20 units/mL. For continuous infusion: dilute 20 units in 100 mL NS to yield 0.2 units/mL concentration. Infuse at 9 mL/hr to deliver 0.03 units/min. Pre-mixed bags simplify field and transport use.
TCCC and TECC Role
Not a TCCC core medication. Used in role 2 and above and hospital settings for catecholamine-refractory shock. Particularly valuable in septic shock when norepinephrine dose exceeds 0.5 to 1 mcg/kg/min and additional vasopressor support is needed. CPP tier may use vasopressin in prolonged casualty care with appropriate authorization and monitoring.
Vasopressin is the non-adrenergic adjunct that lets you keep septic shock patients alive when norepinephrine alone is not enough. The Surviving Sepsis Campaign recommends adding vasopressin at 0.03 units/min when norepinephrine dose approaches 0.25 to 0.5 mcg/kg/min, both to reduce catecholamine burden and to improve hemodynamics through the non-adrenergic mechanism. The drug is operationally distinct from norepinephrine in that it does not produce tachycardia and may actually reduce heart rate by reflex bradycardia in response to vasoconstriction. The mesenteric and digital ischemia risk is real but generally tolerable at the doses used in sepsis (0.01 to 0.04 units/min); higher doses or use in cardiac arrest have largely been abandoned.
Using vasopressin as a first-line vasopressor in septic shock. Current guidelines specify norepinephrine first, with vasopressin added when norepinephrine doses become problematic. The other common mistake is titrating vasopressin like a catecholamine; it is typically given at fixed dose (0.03 units/min) without titration, with adjustments to the concurrent norepinephrine dose if more support is needed. Removal from cardiac arrest protocols (2015 AHA) reflects lack of outcome benefit in that indication.
This drug profile is provided as educational reference material for trained medical providers. It is not medical advice, not a substitute for formal training, and not a substitute for current published guidelines or medical direction.
Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances are subject to additional handling, accountability, and documentation requirements per DEA and state law. Always verify dosing, indications, contraindications, and route of administration against current published guidelines and your local protocols before administration.
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Penn Tactical Solutions publishes this reference for educational purposes. PTS does not provide medical direction and does not assume responsibility for clinical decisions made in the field. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Educational reference for trained medical providers. Not medical advice. Not a substitute for formal training, current published guidelines, or medical direction. Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances require additional storage, accountability, and documentation per DEA and state law.
In a medical emergency, call 911. This reference is not a substitute for emergency medical services.
Verify dosing, indications, and contraindications against current published guidelines and your local protocols before administration. Confirm content currency against the source citation. Penn Tactical Solutions does not provide medical direction. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Vasopressin
| IV/IO | Septic shock: 0.01 to 0.04 units/min continuous infusion (fixed dose, not weight-based for sepsis). Most commonly initiated at 0.03 units/min as adjunct to norepinephrine. Cardiac arrest (historical): 40 units IV/IO once. Diabetes insipidus: variable depending on response, typically 5 to 10 units IV/IM/SC every 6 to 12 hours. (Less than 1 minute) |
| IM | 5 to 10 units IM/SC every 6 to 12 hours for diabetes insipidus. (None) |
| IN | None for sepsis. Desmopressin (DDAVP) intranasal is the analogue used for chronic diabetes insipidus. (None) |
| PO | None (None) |