What is the recommended use and dosage of Carbetocin (a synthetic analogue of oxytocin) for preventing postpartum hemorrhage?

Carbetocin for Prevention of Postpartum Hemorrhage

Carbetocin is recommended as a single 100 μg intramuscular or intravenous dose immediately after delivery of the placenta to prevent postpartum hemorrhage, particularly in women with risk factors for bleeding. 1, 2

Indications and Clinical Use

• Carbetocin is a synthetic analogue of oxytocin with a longer half-life, indicated for the prevention of postpartum hemorrhage following vaginal or cesarean delivery 1, 2
• Particularly effective in high-risk women, including those with multiple pregnancy, polyhydramnios, prolonged labor, grand multiparity, or previous postpartum hemorrhage 3
• Can be used as an alternative to oxytocin in women with hypertensive disorders, as it causes less significant hemodynamic changes 4

Dosage and Administration

• Standard dose: 100 μg as a single dose, administered either:
  • Intramuscularly immediately after delivery of the placenta (vaginal delivery) 1, 3
  • Intravenously as a bolus immediately after delivery of the infant (cesarean delivery) 4, 5
• No need for continuous infusion due to its prolonged uterotonic effect (active for approximately 1-2 hours) 1, 2
• Should be administered after placental delivery in vaginal births and after delivery of the infant in cesarean sections 3, 5

Efficacy Compared to Oxytocin

• Reduces the need for additional uterotonic agents by approximately 32% compared to oxytocin in cesarean deliveries (RR = 0.68,95% CI: 0.55-0.84) 2
• Significantly reduces the need for uterine massage compared to oxytocin (43.4% vs 62.3%, p<0.02) 1
• Results in less blood loss compared to oxytocin:
  • In cesarean deliveries: 430.68 mL vs 552.6 mL (p<0.001) 5
  • In vaginal deliveries: 337.73 mL vs 378 mL (p<0.05) 3
• Associated with smaller decreases in hemoglobin levels post-delivery compared to oxytocin 4, 3, 5

Safety Profile and Adverse Effects

• Similar safety profile to oxytocin with some differences in specific side effects 2
• Common side effects include:
  • Tachycardia (more common than with oxytocin) 3
  • Pruritus (reported in up to 27% of patients) 5
• Less likely to cause significant hypotension compared to oxytocin, making it potentially safer in women with cardiac or hypertensive disorders 4
• Contraindicated in patients with hypersensitivity to carbetocin or oxytocin 2

Special Populations

• Hypertensive women: Carbetocin shows better hemodynamic stability than oxytocin with less significant drops in blood pressure 4
• Cardiac patients: May be preferable to other uterotonics like methylergonovine, which is contraindicated due to risk of vasoconstriction and hypertension 6, 7
• Cesarean delivery: Particularly effective in reducing blood loss and the need for additional interventions 4, 5

Monitoring After Administration

• Monitor vital signs, particularly heart rate and blood pressure, for at least 30-60 minutes after administration 4, 3
• Assess uterine tone regularly in the immediate postpartum period 1, 3
• Continue hemodynamic monitoring for at least 24 hours after delivery in women with cardiac concerns 7

Practical Considerations

• Cost-effectiveness should be considered when choosing between carbetocin and oxytocin, as carbetocin is generally more expensive 2
• In settings where both are available, carbetocin may be preferred for high-risk patients while oxytocin remains appropriate for low-risk cases 2, 3
• For optimal postpartum care, carbetocin should be part of a comprehensive approach that includes monitoring for other causes of bleeding and appropriate follow-up 7