How is vasopressin infusion prepared?

Vasopressin Infusion Preparation

Vasopressin infusion should be prepared by diluting vasopressin injection in normal saline (0.9% sodium chloride) or 5% dextrose in water (D5W) prior to intravenous administration, with unused diluted solution discarded after 18 hours at room temperature or 24 hours under refrigeration. 1

Standard Preparation Methods

• For anaphylaxis management: Prepare vasopressin at a concentration of 0.1 U/mL by adding 25 U of vasopressin to 250 mL of 5% dextrose water or normal saline 2
• For septic shock: Dilute vasopressin injection in normal saline (0.9% sodium chloride) or 5% dextrose in water (D5W) prior to use for intravenous administration 1
• Standard adult concentration for anaphylaxis: An alternative 1:100,000 solution can be prepared by adding 1 mg (1 mL) of vasopressin to 100 mL of saline, administered at 30-100 mL/h (5-15 μg/min) 2

Dosing Guidelines

• For post-cardiotomy shock: Start at 0.03 units/minute 1
• For septic shock: Start at 0.01 units/minute 1
• Titrate up by 0.005 units/minute at 10-15 minute intervals until target blood pressure is reached 1
• Maximum recommended doses: 0.1 units/minute for post-cardiotomy shock and 0.07 units/minute for septic shock 1
• After target blood pressure has been maintained for 8 hours without catecholamines, taper vasopressin by 0.005 units/minute every hour as tolerated 1

Administration Considerations

• Central venous access is preferred for administration of vasopressin 3
• If central access is unavailable or delayed, peripheral IV can be used temporarily 3
• Monitor blood pressure and heart rate every 5-15 minutes during initial titration 3
• Vasopressin is typically added to norepinephrine with the intent of raising mean arterial pressure or decreasing norepinephrine dosage 2

Special Considerations

• For pediatric patients, the "rule of 6" can be used: 0.6 × body weight (kg) = number of milligrams diluted to total 100 mL of saline; then 1 mL/h delivers 0.1 mcg/kg/min 3
• Vasopressin infusion increases blood pressure and urine output while decreasing the dose requirement of norepinephrine 4
• Watch for potential adverse effects including decreased cardiac output, decreased heart rate, arrhythmias, myocardial ischemia, mesenteric ischemia, and digital ischemia 4

Storage and Stability

• Diluted vasopressin solutions (0.2 unit/mL) in 0.9% sodium chloride in PVC bags remain stable with less than 10% degradation over 10 days when refrigerated 5
• Always inspect parenteral drug products for particulate matter and discoloration prior to use 1