Vasopressin Receptor Agonist (V1/V2) Pregnancy: No available data in pregnant women to inform a drug-associated risk; animal reproduction studies have not been conducted. Vasopressin may produce tonic uterine contractions that could threaten the continuation of pregnancy. Dose may need to be increased in the second and third trimester because of increased clearance (US labelling §8.1).

Vasopressin (Surgical — Vasopressor/Haemostasis)

Brand names: Argipressin, Pitressin

Vasopressin (antidiuretic hormone) is used in the surgical and critical-care setting as a potent vasopressor to support blood pressure in refractory vasodilatory shock and to aid haemostasis, including in some endoscopic and oesophageal variceal settings.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Post-cardiotomy shock: starting dose 0.03 units/minute (usual range 0.03 to 0.1 units/minute). Septic shock: starting dose 0.01 units/minute (usual range 0.01 to 0.07 units/minute)

Route: Intravenous infusion after dilution — dilute the 20 units/mL vial in 0.9% sodium chloride or 5% dextrose to a final concentration of 0.1 units/mL (2.5 mL / 50 units in 500 mL) or, if fluid-restricted, 1 unit/mL (5 mL / 100 units in 100 mL)

Frequency: Continuous infusion, titrated to effect

Max: There are limited data for doses above 0.1 units/minute for post-cardiotomy shock and above 0.07 units/minute for septic shock; adverse reactions are expected to increase with higher doses

SOURCE CAVEAT: no eMC/UK SPC was fetched for this bundle — dose is from US labelling (Vasopressin Injection, Fresenius Kabi USA, DailyMed) and must be verified against the UK SPC before publication. INDICATION SCOPE: this label covers vasodilatory shock (post-cardiotomy and septic shock) only — it contains NO haemostatic, local-infiltration, variceal-bleeding or diabetes-insipidus dosing, so the haemostasis element of this page must be sourced separately. TITRATION (§2.2): 'In general, titrate to the lowest dose compatible with a clinically acceptable response.' Titrate up by 0.005 units/minute at 10- to 15-minute intervals until the target blood pressure is reached. WEANING: after target blood pressure has been maintained for 8 hours without the use of catecholamines, taper by 0.005 units/minute every hour as tolerated to maintain target blood pressure. PREPARATION: discard unused diluted solution after 18 hours at room temperature or 24 hours under refrigeration; inspect for particulate matter and discoloration before use. ELDERLY: dose selection should be cautious, usually starting at the low end of the dosing range. PREGNANCY: because of increased clearance of vasopressin in the second and third trimester, the dose may need to be increased. PAEDIATRICS: 'Safety and effectiveness of Vasopressin injection in pediatric patients with vasodilatory shock have not been established' — no paediatric dose is stated; verify any under-18 use against a children's formulary.

Dose auto-extracted from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Known allergy or hypersensitivity to 8-L-arginine vasopressin (the 1 mL single dose vial does not contain chlorobutanol and is therefore contraindicated only on this basis)

Side effects

Decreased cardiac output / decreased cardiac index; right heart failure
Bradycardia, tachyarrhythmias, atrial fibrillation, myocardial ischaemia
Ischaemia — coronary, mesenteric, skin, digital (distal limb ischaemia, ischaemic lesions)
Hyponatraemia; reversible diabetes insipidus after cessation (polyuria, dilute urine, hypernatraemia) — monitor electrolytes, fluid status and urine output after discontinuation
Haemorrhagic shock, decreased platelets, intractable bleeding; acute renal insufficiency; increased bilirubin

Interactions

Catecholamines — pressor effects are expected to be additive on mean arterial pressure and other haemodynamic parameters; haemodynamic monitoring recommended, adjust the vasopressin dose as needed
Indomethacin — may prolong the effect of vasopressin on cardiac index and systemic vascular resistance
Ganglionic blocking agents — may increase the effect of vasopressin on mean arterial blood pressure
Drugs suspected of causing SIADH (e.g. SSRIs, tricyclic antidepressants, haloperidol, chlorpropamide, enalapril, methyldopa, pentamidine, vincristine, cyclophosphamide, ifosfamide, felbamate) — may increase the pressor response
Drugs causing diabetes insipidus — may decrease the pressor response

Clinical monograph

How it works

Acting on vascular V1 receptors it causes intense systemic and splanchnic vasoconstriction, while V2 receptor activity in the kidney promotes water reabsorption; the vasoconstrictor action underlies both its pressor and haemostatic effects.

Prescribing in practice

Its powerful vasoconstriction can provoke myocardial, mesenteric, digital and cutaneous ischaemia, so it should be given by infusion through secure central access under continuous haemodynamic monitoring, with caution in coronary and peripheral vascular disease.
Extravasation can cause severe local tissue necrosis, so confirm line integrity before and during the infusion.
Excess water retention may cause hyponatraemia, requiring attention to fluid balance and sodium.

Monitoring

Monitor blood pressure, cardiac rhythm, peripheral and organ perfusion, urine output, fluid balance and serum sodium continuously during infusion.

Counselling the patient

This is given and closely monitored by the critical-care team.
Tell staff about any chest pain or pain in the fingers, toes, or abdomen.

Evidence & guidelines

Vasopressin is established as an adjunct vasopressor in vasodilatory shock, supported by critical-care evidence and the SPC.

Reference: VASST Trial (NEJM 2008); Surviving Sepsis Campaign 2021; ESC Heart Failure Guidelines; MHRA SPC Argipressin; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways