Name: VASOPRESSIN (PressynR)
Classification: antidiuretic hormone
  • stimulates vascular vasopressin V1 receptors to cause vasoconstriction; tends to not cause hypertension in normotensive patients
  • stimulates vasopressin V2 receptors in the renal tubules to cause fluid retention and prevent fluid loss
  • no alpha or beta adrenergic receptor activity thus may be effective in vasodilatory shock unresponsive to catecholamines or in the presence of acidosis/hypoxia, and will enhance myocardial oxygen delivery without an increase in consumption
  • treatment of septic shock:  0.9 to 1.8 u/hr. Do not titrate, run at fixed dose.
  • organ donor management :  0.9 to 1.8 u/hr. Do not titrate, run at fixed dose.
  • refractory pulseless cardiac arrest:  40 units IV X 1

IV Infusion

40 units/100 mL 0.9% sodium chloride (0.4 units per mL)

Bags are stable for 9 days (refrigerated). 

  • hypovolemia, hypoxemia and acidosis should be corrected concurrently with initiation of therapy
Adverse Effects:


  • GI ischemia
  • coronary ischemia
  • fluid retention
  • sweating
  • tremor
  • abdominal cramping, nausea, vomiting, eructation, diarrhea
  • bradycardia
  • arrhythmias
  • decreased cardiac output
Drug Interactions:
  • vasopressin + ganglionic blocking agents = increased vasopressin pressor effect
  • vasopressin + lithium = decreased antidiuretic activity
  • vasopressin + carbamazepine = increased antidiuretic activity
Monitoring Therapy:
  • IV site
  • blood pressure
  • continuous heart rate and ECG rhythm
  • urine output
  • central or mixed venous oxygen saturation
  • lactate
  • blood gases
  • changes in skin colour or temperature 
  • chest pain, diarrhea, abdominal pain  
CCTC Protocol:
  • May be administered by IV infusion by a nurse in Adult Critical Care.
  • Must be administered via central venous access device; in emergency situations may be temporarily infused through a peripheral vasuclar access device until a central venous line can be established.
  • Patient requires placement of an arterial line to monitor BP.
  • Continuous infusions must be administered by infusion device and the pump library must be enabled.
  • Should not be infused via the proximal injectate port (blue) of a pulmonary artery catheter. If this is the only available central venous line, it may be administered through the proximal injectate port but thermodilution cardiac output measurements must not be measured during infusion).

Lynne Kelly, Pharmacist, CCTC
Brenda Morgan, Clinical Nurse Specialist, CCTC
Last Update: May 12, 2022