What is the typical dose of vasopressin (antidiuretic hormone) for treating septic shock?

Vasopressin Dosing for Septic Shock

The standard dose of vasopressin for septic shock is 0.03 units/minute when added as a second-line agent to norepinephrine, with an acceptable range of 0.01-0.03 units/minute. 1, 2, 3

Initial Dosing Protocol

• Start vasopressin at 0.01 units/minute as the FDA-approved initial dose for septic shock 3
• Titrate upward by 0.005 units/minute increments at 10-15 minute intervals until target mean arterial pressure (MAP) of 65 mmHg is achieved 3
• The most commonly recommended maintenance dose is 0.03 units/minute, which should be initiated when norepinephrine requirements reach 5-15 μg/minute or higher 1, 2
• Maximum recommended dose is 0.07 units/minute for septic shock, though limited safety data exist above this threshold 3

Critical Timing and Indications

• Never use vasopressin as initial monotherapy—it must always be added to norepinephrine, not used alone 1, 2
• Add vasopressin when norepinephrine alone fails to maintain MAP ≥65 mmHg despite adequate fluid resuscitation (minimum 30 mL/kg crystalloid in first 3 hours) 1
• The goal is either to raise MAP to target OR to decrease norepinephrine dosage while maintaining hemodynamic stability 1

Dose Limitations and Safety Thresholds

• Do not exceed 0.03-0.04 units/minute except as salvage therapy when all other vasopressors have failed 1, 2
• Doses above 0.04 units/minute are associated with cardiac, digital, and splanchnic ischemia 1, 4
• The safe dose range for vasopressin in septic shock is narrow—animal studies demonstrate that moderately higher doses cause marked decreases in mesenteric and renal blood flow despite maintaining cerebral perfusion 4
• Adverse reactions increase substantially with higher doses, and there are limited safety data for doses above 0.07 units/minute 3

Monitoring Requirements

• Place an arterial catheter for continuous blood pressure monitoring as soon as practical in all patients requiring vasopressors 1, 2
• Administer through central venous access 1
• Monitor for signs of excessive vasoconstriction: digital ischemia, decreased urine output, rising lactate, or worsening organ dysfunction 1
• Consider measuring cardiac output when using vasopressin, as maintaining normal or elevated flow is desirable with pure vasopressors 2

Weaning Strategy

• After target blood pressure has been maintained for 8 hours without catecholamines, taper vasopressin by 0.005 units/minute every hour as tolerated 3
• Gradual dose reduction is preferred over abrupt discontinuation 1

When to Escalate Beyond Vasopressin

• If norepinephrine requirements remain high despite vasopressin at 0.03 units/minute, add epinephrine as a third agent rather than increasing vasopressin dose 1
• For persistent hypoperfusion despite adequate vasopressor support, add dobutamine (up to 20 mcg/kg/min) rather than escalating vasopressors further, particularly when myocardial dysfunction is evident 1

Evidence Base

The landmark VASST trial demonstrated no mortality difference between low-dose vasopressin (0.01-0.03 units/minute) and norepinephrine in septic shock (28-day mortality 35.4% vs 39.3%, P=0.26), though a subgroup with less severe septic shock showed lower mortality with vasopressin (26.5% vs 35.7%, P=0.05) 5. This supports vasopressin's role as a norepinephrine-sparing agent rather than a mortality-reducing intervention 6.