Carbetocin Adverse Events: What the Label and Studies Report

Label status, and whether a boxed warning exists

Carbetocin is a prescription medicine. It is a long acting synthetic analogue of oxytocin that acts at oxytocin receptors in uterine smooth muscle, and it is approved in a number of countries, including jurisdictions in Europe, Canada, Asia and Latin America, for prevention of uterine atony and excessive bleeding following delivery. It is not an approved product in the United States. Approved carbetocin labeling in the jurisdictions where the drug is marketed does not carry a United States style boxed warning; the strongest label level statements appear instead as contraindications, as warnings and precautions, and as tabulated adverse reactions. Label text differs by country and by formulation, so the approved monograph for a specific product is the governing document rather than any summary of it.

Carbetocin appears in the obstetric literature as one of several uterotonic options for the third stage of labour and for caesarean delivery, and reviews of postpartum haemorrhage prevention have placed it alongside oxytocin, misoprostol and ergot alkaloids when describing agent selection and programme level implementation (PMID 42285117, PMID 38462248). An earlier review of strategies for preventing haemorrhage in the third stage of labour also discussed carbetocin among the uterotonic agents under evaluation at that time (PMID 15017343).

This page is for educational purposes only and is not medical advice; consult a licensed physician about any medicine, symptom or treatment decision. Any question about whether a uterotonic is appropriate in a given pregnancy or delivery belongs with the prescribing clinician.

Contraindications and precautions that labeling lists

Carbetocin product monographs generally restrict use to the period after delivery of the infant and state that the drug is not indicated for induction or augmentation of labour. Label level contraindications and precautions commonly described include the following categories:

• Use before delivery of the infant, including for induction of labour.
• Known hypersensitivity to carbetocin or to oxytocin.
• Serious cardiovascular disorders, with particular attention to coronary artery disease.
• Serious hepatic or renal impairment.
• Epilepsy, because oxytocic agents may lower seizure threshold.
• Pre-eclampsia and eclampsia, where labeling advises caution.
• Risk of water retention and hyponatraemia when oxytocic drugs are combined with large volumes of intravenous fluid.

Reviews written for anaesthesiologists have covered uterotonics, magnesium sulphate and antibiotics used during childbirth and the peripartum period, including the circulatory consequences that can follow administration of these agents in the operating room (PMID 38428678). An international consensus statement on the use of uterotonic agents during caesarean section addressed agent selection and administration practice, and discussed the haemodynamic adverse effects associated with uterotonic administration in that setting (PMID 31347151).

Cardiovascular adverse events: What Studies Report

Hypotension, flushing, tachycardia, chest pain, palpitations and dyspnoea appear in carbetocin adverse reaction listings, reflecting the vasodilatory and chronotropic effects shared across the oxytocin receptor agonist class. The international consensus statement on uterotonic agents during caesarean section examined how these agents are given at caesarean delivery and considered the haemodynamic adverse effects that can follow, including effects relevant to patients under spinal or epidural anaesthesia (PMID 31347151). A narrative review aimed at anaesthesiologists likewise grouped uterotonics among the obstetric drugs whose cardiovascular effects researchers consider during peripartum care (PMID 38428678).

Frequencies for these events are not uniformly quantified across published summaries, and labeling categories differ between monographs, so comparisons of percentage rates between carbetocin and comparator uterotonics are best read directly from the trial or monograph being referenced rather than from aggregated descriptions.

Gastrointestinal adverse events: What Studies Report

Nausea, vomiting, abdominal pain and metallic taste are among the gastrointestinal reactions carried in carbetocin labeling. In comparative obstetric research, gastrointestinal symptoms are typically collected as secondary tolerability outcomes rather than as primary endpoints. A meta-analysis of carbetocin versus oxytocin for prevention of postpartum haemorrhage after vaginal delivery pooled randomised data and reported both efficacy outcomes and adverse event comparisons between the two agents (PMID 31764790). That analysis, which addressed vaginal delivery populations rather than caesarean populations, reported that carbetocin was associated with a reduced requirement for additional uterotonic agents compared with oxytocin (PMID 31764790).

Neurological and general adverse events: What Studies Report

Headache, tremor, dizziness, chills and a sensation of warmth are listed in carbetocin adverse reaction tables, together with pruritus, back pain and anaemia in some monographs. These symptoms overlap substantially with the profile described for oxytocin, which is expected given the shared receptor target. Reviews of third stage of labour management have described how uterotonic choice is weighed against such tolerability considerations alongside haemorrhage prevention goals (PMID 38462248).

Uterine, placental and bleeding events: What Studies Report

Because carbetocin produces a sustained uterine contraction, events related to the timing of that contraction have been described. A case report published in 2023 documented placental interception after carbetocin administration, which researchers characterised as a relatively rare adverse event in which the placenta was trapped by the contracting uterus (PMID 37033610). A single case report establishes that an event can occur and does not establish how often it occurs.

At the opposite end of the response spectrum, uterine atony can persist despite uterotonic administration. A review of refractory uterine atony described this clinical problem and the ongoing difficulty of managing bleeding that does not respond to first line agents (PMID 34391025). Observational work in postpartum haemorrhage attributed to uterine atony has likewise examined adjunct approaches used when bleeding continues after standard management (PMID 39183400).

Hypersensitivity: What Studies Report

Hypersensitivity reactions, including rash and pruritus, appear in carbetocin labeling, and known hypersensitivity to carbetocin or oxytocin is listed as a contraindication. Severe hypersensitivity, including anaphylactoid reactions, has been described for oxytocin receptor agonists as a class in product information. Any suspected allergic reaction is a matter for immediate clinical assessment rather than self interpretation.

Reported events grouped by body system

Comparisons with oxytocin: What Studies Report

Most comparative safety information for carbetocin comes from trials that used oxytocin as the active comparator. The 2019 meta-analysis of randomised trials in vaginal delivery populations examined postpartum haemorrhage outcomes and adverse events and reported a reduced need for additional uterotonic agents with carbetocin relative to oxytocin (PMID 31764790). Guidance and review literature on haemorrhage prevention has described how such comparative findings, along with cost, storage and supply considerations, feed into national and programme level decisions about which uterotonic is stocked and used (PMID 42285117, PMID 38462248).

Investigational research beyond the approved indication: What Studies Report

Any use of carbetocin outside the approved obstetric indication is investigational. A phase 3 randomised trial evaluated investigational intranasal carbetocin in Prader-Willi syndrome and reported reductions in hyperphagia, anxiousness and distress among the outcomes assessed, with adverse events collected as part of the trial safety reporting (PMID 36633570). That trial studied an intranasal formulation and a population entirely distinct from obstetric use, so its tolerability findings do not transfer to the injectable obstetric product.

Preclinical research has also examined oxytocin receptor agonists in models of perinatal brain injury. The study published in Glia reported that an oxytocin receptor agonist reduced perinatal brain damage in an animal model by targeting microglia (PMID 30506969), and a French language review discussed oxytocin signalling as a possible neuroprotective target (PMID 36744980). Findings in animals and in receptor pharmacology describe mechanisms under investigation and do not describe outcomes in people.

What the published record does not settle

• Event frequencies are not harmonised across monographs and trials, so a single rate figure for any carbetocin adverse event cannot be read off the literature as a whole (PMID 31764790).
• Rare events such as placental interception are described in case reports, which cannot quantify incidence (PMID 37033610).
• Long term maternal or neonatal outcome data specific to carbetocin exposure remain limited relative to the volume of short term efficacy comparisons (PMID 38462248).
• Investigational formulations and indications generate their own safety datasets that are not interchangeable with the obstetric injection (PMID 36633570).

Questions that belong with a prescriber

Symptoms that appear after any uterotonic has been given, including chest discomfort, breathlessness, severe headache, persistent vomiting, rash or ongoing bleeding, are clinical matters. A prescribing clinician or the attending obstetric team is the right place to raise them, including questions about cardiac, hepatic, renal or seizure history, about pre-eclampsia, about allergy history to oxytocin, and about which uterotonic a given hospital protocol uses (PMID 31347151). Talk to your prescriber rather than acting on any summary of labeling or trial data.

References

• International consensus statement on the use of uterotonic agents during caesarean section (Anaesthesia, 2019)
• Third stage of labor: evidence-based practice for prevention of adverse maternal and neonatal outcomes (American Journal of Obstetrics and Gynecology, 2024)
• Current strategies for the prevention of postpartum haemorrhage in the third stage of labour (Current Opinion in Obstetrics and Gynecology, 2004)
• Prevention of postpartum haemorrhage: from evidence to implementation at scale (Lancet, 2026)
• Refractory uterine atony: still a problem after all these years (International Journal of Obstetric Anesthesia, 2021)
• Carbetocin vs oxytocin for prevention of postpartum hemorrhage after vaginal delivery: A meta-analysis (Medicine, 2019)
• Case report: A relatively rare adverse event caused by carbetocin, placenta interception (Frontiers in Pharmacology, 2023)
• Uterotonics, magnesium sulphate and antibiotics during childbirth and peripartum: Important obstetric drugs for the anaesthesiologist (Revista Espanola de Anestesiologia y Reanimacion, 2024)
• Shenghua decoction for postpartum hemorrhage attributed to uterine atony: An observational study (Medicine, 2024)
• Intranasal Carbetocin Reduces Hyperphagia, Anxiousness, and Distress in Prader-Willi Syndrome: CARE-PWS Phase 3 Trial (Journal of Clinical Endocrinology and Metabolism, 2023)
• Oxytocin receptor agonist reduces perinatal brain damage by targeting microglia (Glia, 2019)
• Oxytocin: a new target for neuroprotection? (Biologie Aujourd'hui, 2022)