Carbetocin

• Prevention of Postpartum Hemorrhage (PPH):
  Prevention of uterine atony and subsequent postpartum hemorrhage following vaginal delivery or cesarean section.
• Off-label Uses:
  Occasionally used for management of incomplete or missed miscarriage and for labor induction in some settings, though primarily indicated for PPH prevention.

• Adults:
• After vaginal delivery: Single intravenous (IV) or intramuscular (IM) dose of 100 micrograms immediately after delivery of the baby.
• After cesarean section: Single IV or IM dose of 100 micrograms administered preferably within 1 minute of delivery of the infant.
• Pediatrics:
  Not recommended.
• Elderly:
  Not applicable.
• Renal/Hepatic Impairment:
  No specific dose adjustment; use with caution in severe hepatic impairment due to limited data.
• Administration Route:
  IV injection over 1 minute or deep IM injection.
• Duration:
  Single dose administration; additional uterotonic agents may be required if bleeding persists.

Carbetocin is a long-acting synthetic analogue of oxytocin that binds selectively to oxytocin receptors in uterine smooth muscle, activating G-protein coupled receptors that increase intracellular calcium concentrations. This leads to sustained uterine contractions (myometrial contractions) which help reduce uterine bleeding by promoting uterine muscle tone and constriction of blood vessels within the uterus, effectively preventing postpartum hemorrhage.

• Absorption:
  Rapidly absorbed after IM or IV administration.
• Bioavailability:
  Nearly 100% after IV administration; IM bioavailability is slightly less but effective.
• Distribution:
  Volume of distribution approximately 0.1 L/kg.
• Metabolism:
  Primarily metabolized by liver and plasma enzymes via peptide hydrolysis.
• Half-life:
  Approximately 40 minutes, longer than native oxytocin (3–5 minutes).
• Elimination:
  Metabolites and unchanged drug excreted mainly in urine.

• Pregnancy:
  Category not assigned; used specifically during labor and delivery under medical supervision. Not for use before delivery except in management of labor induction (off-label).
• Lactation:
  Limited data; expected to be low risk due to rapid metabolism and low systemic exposure. Use with caution.

• Primary: Uterotonic agent
• Subclass: Oxytocin analogue

• Known hypersensitivity to carbetocin or oxytocin.
• Severe pre-eclampsia or eclampsia.
• Significant cardiovascular disease (e.g., coronary artery disease).
• Fetal distress or abnormal fetal presentations where vaginal delivery is contraindicated.
• Use during labor induction or augmentation in cases where vaginal delivery is contraindicated.

• Use cautiously in patients with cardiovascular disorders due to risk of hypertension and arrhythmias.
• Monitor for water intoxication and hyponatremia with repeated or high-dose administration.
• Observe for uterine hypertonicity or rupture, especially in patients with uterine scars.
• Monitor vital signs during and after administration.
• Immediate medical attention if anaphylaxis or hypersensitivity reactions occur.

Common:

• Nausea, vomiting
• Headache
• Abdominal pain or cramping
• Flushing or warmth sensation
• Hypotension or hypertension

Serious/Rare:

• Anaphylaxis
• Uterine hyperstimulation or rupture
• Arrhythmias or tachycardia
• Seizures (rare)

• Additive effects with other uterotonic agents may increase risk of uterine hypertonicity.
• Concomitant use with vasoconstrictors or antihypertensives requires monitoring of blood pressure.
• No significant CYP450 enzyme interactions reported.

• Recent clinical guidelines recommend carbetocin as an effective alternative to oxytocin for PPH prevention, especially in settings where cold chain storage is challenging.
• WHO recommends carbetocin as a first-line option for PPH prevention due to its longer duration and stability profile.
• Ongoing studies assess efficacy in low-resource settings with single-dose protocols.

• Store at 2°C to 8°C (refrigerated).
• Protect from light; keep in original packaging until use.
• Do not freeze.
• Discard any unused portion after opening.