Vasopressin Incompatibilities
Vasopressin is incompatible with solutions containing mannitol, certain electrolyte solutions, and medications that can cause precipitation when mixed. Based on pharmaceutical guidelines, vasopressin requires careful consideration when administered with other medications due to potential physical and chemical incompatibilities.
Physical and Chemical Incompatibilities
Mannitol: Vasopressin should not be mixed with mannitol solutions as this can cause precipitation and reduce efficacy 1
Certain electrolyte solutions: Incompatible with solutions containing high concentrations of specific electrolytes that may alter the stability of vasopressin 1
pH-sensitive medications: Vasopressin has specific pH requirements for stability, and mixing with medications that significantly alter this pH range can lead to degradation of the active compound
Administration Considerations
Compatible Solutions
- Normal saline (0.9% sodium chloride): Preferred diluent for vasopressin administration 1
- Dextrose 5% in water (D5W): Generally compatible for dilution of vasopressin
Administration Route Precautions
- Dedicated line preferred: When possible, administer vasopressin through a dedicated IV line to avoid potential drug interactions
- Central venous access: Recommended for continuous infusion of vasopressin, especially at higher doses or for prolonged administration 2
- Arterial line monitoring: Suggested for all patients requiring vasopressors including vasopressin to accurately monitor blood pressure response 2
Clinical Considerations
- Dosing range: For vasodilatory shock, the recommended dose is 0.01-0.04 units/minute 1
- Monitoring: Continuous monitoring of blood pressure, heart rate, and tissue perfusion is essential during vasopressin administration
- Potential side effects: Excessive vasoconstriction can lead to tissue ischemia, particularly in the splanchnic circulation, extremities, and skin 3
Special Populations
- Pregnancy: Clearance of vasopressin increases gradually over pregnancy, with up to 5-fold increase by term due to placental vasopressinase 1
- Renal impairment: Vasopressin is contraindicated in moderate to severe renal impairment (creatinine clearance <50 mL/min) 4
Drug Interactions
- Indomethacin: More than doubles the time to offset vasopressin's effect on peripheral vascular resistance and cardiac output 1
- Ganglionic blocking agents: Tetra-ethylammonium increases the pressor effect of vasopressin by approximately 20% 1
When administering vasopressin, always check the manufacturer's guidelines for the most current information on drug incompatibilities and consult with a pharmacist when uncertainty exists about potential interactions with other medications.