From the FDA Drug Label
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 duration of oxytocin administration after postpartum hemorrhage (PPH) is not explicitly stated in the drug label.
- Key point: The label only mentions that oxytocin should be run at a rate necessary to control uterine atony, but it does not provide information on how long the infusion should be continued. Therefore, no conclusion can be drawn regarding the specific duration of oxytocin administration after PPH 1.
From the Research
Oxytocin should be administered for at least 24 hours after postpartum hemorrhage (PPH) has been controlled, as the risk of secondary PPH remains elevated in the immediate postpartum period 2. The typical regimen involves an initial IV bolus of 10 units followed by an infusion of 20-40 units in 1000 mL of crystalloid solution at 125 mL/hour (approximately 40-60 mU/min). For maintenance therapy after hemorrhage control, continue oxytocin at a lower rate of 10-20 units in 1000 mL at 125 mL/hour for the remainder of the 24-hour period. This extended administration is crucial because the risk of secondary PPH remains elevated in the immediate postpartum period. Oxytocin works by stimulating rhythmic uterine contractions, increasing the resting tone of the myometrium, and enhancing the frequency and force of contractions, which helps maintain uterine contraction and prevents further bleeding. Some key points to consider when administering oxytocin include:
- Adequate IV access should be maintained throughout treatment
- The patient should be monitored for vital signs, uterine tone, and bleeding
- Fluid intake and output should be carefully tracked, as oxytocin has antidiuretic effects that could lead to water intoxication with prolonged high-dose administration It's also worth noting that combined therapy rather than oxytocin alone should be advised for preventing postpartum hemorrhage, as evidence suggests that the use of second-line uterotonics such as methylergonovine, misoprostol, and carboprost in combination with oxytocin has an additive or synergistic effect and a greater risk reduction for postpartum hemorrhage prevention compared with oxytocin alone 2. However, the most recent and highest quality study on this topic is from 2023, which suggests that oxytocin is still the first-line uterotonic agent in the United States for prevention of postpartum hemorrhage, but its effectiveness can be enhanced when used in combination with other therapies 2. Additionally, a 2025 study is currently underway to compare the efficacy of carboprost and oxytocin for the initial treatment of PPH, which may provide further guidance on the optimal treatment regimen in the future 3. But for now, the current evidence supports the use of oxytocin for at least 24 hours after PPH has been controlled, as part of a comprehensive treatment plan that prioritizes morbidity, mortality, and quality of life as the outcome 2, 4, 5.