V1 agonist
Vasopressin
Vasostrict Vasopressor — violet 20 units/mL (diluted)
Non-adrenergic vasoconstrictor for refractory vasoplegia.
Typical adult doses
| Indication | Dose | Onset | Duration |
|---|---|---|---|
| OR bolus (off-label, local practice) | 0.5–1 unit IV | — | — |
| Infusion | ≈0.03 units/min | — | — |
Mechanism
V1 receptor agonist → vascular smooth-muscle contraction independent of adrenergic receptors.
Key effects
- ↑ SVR
Watch out for
- Splanchnic and digital ischemia at high doses
- Bolus practice varies — confirm with your attending
Pimp questions
Pimp question
Why does vasopressin help hypotension in patients on ACE inhibitors/ARBs?
Answer
It raises SVR through a non-adrenergic, non-angiotensin pathway.