Intravenous Ephedrine Dosing for Hypotension
The FDA-approved initial IV dose of ephedrine is 5 to 10 mg administered as an intravenous bolus, with additional boluses as needed, not to exceed a total dosage of 50 mg. 1
Preparation and Administration
Ephedrine sulfate injection (50 mg/mL) must be diluted before IV bolus administration. 1
- Prepare a 5 mg/mL solution by withdrawing 50 mg (1 mL of 50 mg/mL) and diluting with 9 mL of either 5% dextrose injection or 0.9% sodium chloride injection 1
- Inspect the solution visually for particulate matter and discoloration prior to administration 1
- Administration should be performed by trained healthcare providers 1
Dosing Protocol
Initial dose: 5 to 10 mg IV bolus 1
- Administer additional boluses as needed based on blood pressure response 1
- Maximum total cumulative dose: 50 mg 1
- Titrate to achieve the desired blood pressure goal 1
Special Population: Obstetric Anesthesia
For spinal anesthesia during cesarean delivery, research demonstrates variable efficacy with different dosing strategies:
- Prophylactic dosing of 30 mg IV reduced hypotension incidence to 35% (compared to 80-95% with lower doses or placebo), but caused reactive hypertension in 45% of patients 2
- Prophylactic infusion starting at approximately 5 mg/min (mean total dose 31.6 mg) maintained systolic blood pressure at 90-100% of baseline without reactive hypertension 3
- Lower prophylactic doses (10-20 mg) were less effective, with hypotension occurring in 80-85% of patients 2
Clinical caveat: The 10 mg bolus given simultaneously with spinal anesthesia does not prevent hypotension effectively (70% incidence), requiring additional rescue doses 4
Pediatric Dosing Considerations
In neonates and infants below 6 months undergoing general anesthesia:
- The currently recommended dose of 0.1 to 0.2 mg/kg frequently results in therapeutic failure 5
- Ongoing research is evaluating higher doses (0.6 to 1.4 mg/kg) to determine optimal dosing in this population 5
Critical Warnings
Tachyphylaxis and tolerance: Repeated administration can result in diminished response, requiring alternative pressors 1
Risk of reactive hypertension: When used prophylactically (rather than for treatment), ephedrine is associated with increased incidence of hypertension 1
Drug interaction with oxytocics: Serious postpartum hypertension and stroke have been reported when ephedrine is combined with oxytocic drugs (methylergonovine, ergonovine) 1
- Carefully monitor blood pressure in patients receiving both medications 1