vasopressin
Brand: Pitressin, Vasostrict
ISMP High Alert Prototype Drug
Drug Class: vasopressor
Drug Family: vasopressor
Subclass: ADH (antidiuretic hormone) analog
Organ Systems: cardiovascularrenal
Mechanism of Action
V1a receptor activation causes vasoconstriction; V2 receptor increases water reabsorption (antidiuretic effect); does not cause tachycardia unlike catecholamines.
V1a vasopressin receptor (vascular smooth muscle)V2 vasopressin receptor (renal tubule)
Indications
- septic shock (vasodilatory — adjunct to NE)
- vasodilatory shock (post-cardiac surgery)
- esophageal varices bleeding (IV)
- diabetes insipidus (central)
- cardiac arrest (no longer in ACLS 2010)
Contraindications
- anaphylaxis (relative)
- coronary artery disease (relative — vasoconstriction)
Adverse Effects
Common
- oliguria
- ischemia
- nausea
- abdominal cramping
Serious
- severe ischemia (mesenteric, coronary)
- hyponatremia (SIADH-like)
Pharmacokinetics (ADME)
| Absorption | IV/IM/SQ |
| Distribution | wide |
| Metabolism | hepatic and renal |
| Excretion | renal |
| Half-life | 10-35 min (vasopressor context) |
| Onset | immediate IV |
| Peak | 1-2 hours IM |
| Duration | 20-120 min |
| Protein Binding | very low |
| Vd | 0.1-0.14 L/kg |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| other vasopressors | additive vasoconstriction | moderate |
Nursing Considerations
- VASST trial: vasopressin 0.03-0.04 units/min as catecholamine-sparing agent in septic shock
- Fixed dose (0.03-0.04 U/min) in septic shock — do NOT titrate
- Monitor for signs of ischemia (fingers, toes, mesenteric)
- Do not abruptly discontinue (rebound vasodilation) in vasopressor-dependent patients
Clinical Pearls
- VASST/VANISH trials: vasopressin reduces NE requirements in septic shock but does not reduce mortality
- Septic shock: endogenous vasopressin levels fall — physiologic replacement rationale
Safety Profile
Pregnancy use-with-caution
Lactation use-with-caution
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required
Concordance Terms
Cross-referenced clinical concepts — click any term to see all content where it appears.