Vasopressin Drip Preparation
Dilute vasopressin 20 units/mL by adding 20 units to 100 mL of normal saline (0.9% sodium chloride) or 5% dextrose in water (D5W) to create a 0.2 units/mL concentration for intravenous administration. 1
Standard Preparation Protocol
FDA-Approved Dilution Method
- Add 20 units of vasopressin to 100 mL of diluent (either normal saline or D5W) to achieve a final concentration of 0.2 units/mL 1
- Alternative concentration: Add 20 units to 200 mL of diluent to create a 0.1 units/mL solution 1
- For higher volume preparation: Add 25 units to 250 mL of D5W or normal saline to achieve 0.1 units/mL 2
Stability and Storage
- Discard unused diluted solution after 18 hours at room temperature or 24 hours under refrigeration 1
- Research demonstrates that vasopressin 0.2 units/mL in normal saline remains stable with less than 10% degradation over 10 days when refrigerated 3
Administration Guidelines
Starting Doses by Indication
- Post-cardiotomy shock: Start at 0.03 units/minute 1
- Septic shock: Start at 0.01 units/minute 1, 4
- Vasodilatory shock (general): 0.01-0.04 units/minute range 4, 5
Titration Protocol
- Increase by 0.005 units/minute at 10-15 minute intervals until target blood pressure is achieved 1
- Maximum dose for post-cardiotomy shock: 0.1 units/minute (limited data above this) 1
- Maximum dose for septic shock: 0.07 units/minute (limited data above this) 1
- Critical safety threshold: Do not exceed 0.04 units/minute without extreme caution, as doses above this may lead to cardiac arrest 5
Weaning Protocol
- After target blood pressure maintained for 8 hours without catecholamines, taper by 0.005 units/minute every hour as tolerated 1
Route and Monitoring
Access Requirements
- Central venous access is strongly preferred to minimize extravasation risk 2
- Peripheral IV may be used temporarily if central access is unavailable or delayed 2
Monitoring Parameters
- Monitor blood pressure and heart rate every 5-15 minutes during initial titration 2
- Target mean arterial pressure (MAP) ≥65 mmHg in vasodilatory shock 2
- Vasopressin is typically added to norepinephrine therapy rather than used as monotherapy 2
Critical Safety Considerations
Serious Adverse Effects
- Ischemic complications: skin lesions, digital ischemia, mesenteric ischemia, and coronary ischemia are significant risks 5
- Decreased cardiac output and bradycardia are common 1
- Tachyarrhythmias and hyponatremia may occur 1
Contraindications
- Known allergy or hypersensitivity to 8-L-arginine vasopressin or chlorobutanol 1
- May worsen cardiac function in vulnerable patients 1
Drug Interactions
- Additive pressor effects with catecholamines - expect enhanced blood pressure response 1
- Indomethacin may prolong vasopressin effects 1
- Ganglionic blockers or drugs causing SIADH may increase pressor response 1
Special Clinical Context
Anaphylaxis (Alternative Use)
- For refractory anaphylaxis not responding to epinephrine and fluids, an alternative 1:100,000 solution can be prepared by adding 1 mg (1 mL) to 100 mL saline, administered at 30-100 mL/h 2