From the FDA Drug Label
DOSAGE AND ADMINISTRATION ... Control of Postpartum Uterine Bleeding Intravenous Infusion (Drip Method) – To control postpartum bleeding, 10 to 40 units of oxytocin may be added to 1,000 mL of a nonhydrating diluent and run at a rate necessary to control uterine atony The maximum safe dosage of oxytocin for controlling postpartum uterine bleeding is 10 to 40 units added to 1,000 mL of a nonhydrating diluent, administered at a rate necessary to control uterine atony 1.
- The dose is determined by the patient's response and should be adjusted accordingly.
- Close monitoring of the patient is necessary to avoid uterine hyperactivity or fetal distress.
From the Research
For postpartum hemorrhage due to uterine atony, the maximum safe dosage of oxytocin is typically less than 5 units, with some studies suggesting a bolus dose of 0.5-3 units, as higher doses may not provide additional benefits and could increase the risk of adverse effects, as noted in studies such as 2 and 3.
Key Considerations
- The optimal prophylactic dose of oxytocin differs depending on the patient population, with less than 5 units often sufficient for preventing postpartum hemorrhage, as suggested by 3.
- Higher infusion doses (up to 80 IU/500 mL) and bolus doses of oxytocin may be more effective than lower doses or protracted administration of a fixed dose at reducing outcome measures of postpartum hemorrhage, particularly among cesarean deliveries, as noted in 4.
- Combined therapy with other uterotonic agents, such as methylergonovine or carboprost, may be more effective than oxytocin alone in preventing postpartum hemorrhage, as suggested by 5.
- The use of second-line uterotonics, such as methylergonovine or carboprost, may be necessary if oxytocin alone fails to control hemorrhage, with no significant difference detected between these two agents in terms of efficacy, as noted in 6.
Administration and Monitoring
- Oxytocin should be administered as an initial IV bolus of 0.5-3 units, followed by an infusion of 10-20 milliunits/minute, as needed, to control bleeding.
- Patients should be monitored for vital signs, fluid balance, and signs of adverse effects, such as hypotension, water intoxication, and cardiac arrhythmias.
- If oxytocin alone fails to control hemorrhage within 15-30 minutes, additional interventions, including the use of second-line uterotonics or other therapies, should be initiated promptly.