II. Indications
-
Vasopressor (and Vasoconstrictor)
- Shock
- Adjunct to other Vasopressors (e.g. Norepinephrine) in refractory Hypotension (especially Septic Shock)
- Bleeding Esophageal Varices
- Cardiac Arrest
- Shock
- Antidiuretic Hormone Replacement
III. Physiology: ADH Related Water Regulation Mechanisms
- See Sodium and Water Homeostasis
- Antidiuretic Hormone (ADH or Arginine Vasopressin) overall effect is to increase renal water reaborption
- ADH is a polypeptide released from the posterior pituitary
- Response to increased plasma osmolality (and increased plasma Sodium concentration, Hypernatremia)
- Response to decreased plasma osmolality (and decreased plasma Sodium concentration, Hyponatremia)
- Decreased ADH secretion
- Free water diuresis
- Increased plasma Sodium concentration (and increased plasma osmolality)
- Direct Sympathetic System effects to increase Blood Pressure
- See Blood Pressure Physiology
- Antidiuretic Hormone (Vasopressin) strongly increases Vasoconstriction and Peripheral Vascular Resistance
- Abnormal Antidiuretic Hormone
- Syndrome Inappropriate ADH Secretion (SIADH)
- Inappropriate ADH release, resulting in water retention despite normal Sodium and water status
- Results in Isovolemic Hypoosmolar Hyponatremia
- Diabetes Insipidus
- Excessive constant water diuresis due lack of pituitary ADH release or lack of renal response
- Nephrogenic Diabetes Insipidus
- Central Diabetes Insipidus
- Syndrome Inappropriate ADH Secretion (SIADH)
IV. Mechanism: Vasopressin
- Receptor Activity
- Exclusively at Vasopressin receptors (some on vasculature)
- Effects
- Increases Systemic Vascular Resistance while still maintaining CNS and cardiac Blood Flow
- Effective, even in severe acidosis
V. Dosing: Adults
-
Diabetes Insipidus
- Vasopressin 5-10 units IM or SQ twice daily to four times daily as needed
-
Septic Shock
- Vasopressin Infusion: 0.01 to 0.04 units/min (up to 0.1 units/min have been used)
-
Cardiac Arrest (old ACLS guidelines)
- Vasopressin 40 units IV once (second dose may be given after 3 minutes if if first ineffective)
- Per older guidelines, Vasopressin 40 units IV once was given instead of Epinephrine 1 mg every 3-5 min
-
Bleeding Esophageal Varices
- Vasopressin 0.2 to 0.4 units/min (up to max of 0.8 units/min - very high dose)
VI. Adverse Effects
- Higher doses may be associated with Myocardial Ischemia
- Hyponatremia (and Water Intoxication)
- Tissue necrosis on extravasation
- Gastrointestinal distress (Abdominal cramping, Nausea, Vomiting, Flatulence)
- Headache
- Sweating
VII. Resources
- Vasopressin Injection Solution (DailyMed)
VIII. References
- (2020) Tarascon Pharmacopeia, accessed 12/28/2020