Carbetocin Chemical formula
Synonyms: Carbetocina; Carbétocine; Carbetocinum; Karbetocin; Karbetosiini. 2,1-Desamino-4,1-desthioO 4,2 -methyl[1-homocysteine]oxytocin; 1-Butyric acid-2-[3-(p-methoxyphenyl)tocin.
Cyrillic synonym: Карбетоцин.

💊 Chemical information

Chemical formula: C45H69N11O12S = 988.2.
CAS — 37025-55-1.
ATC — H01BB03.
ATC Vet — QH01BB03.

💊 Adverse Effects and Precautions

Carbetocin has similar adverse effects and precautions to those associated with oxytocin when it is used after caesarean section. However, carbetocin should not be used at any stage of labour before delivery of the infant because its effects on the uterus last for several hours.

Breast feeding.

In 5 women who were 7 to 14 weeks postpartum, carbetocin was measured in the breast milk within 90 minutes of a single 70-microgram intramuscular dose.1 The ratio of milk to plasma concentrations was low, suggesting that very little carbetocin was distributed into breast milk. Licensed UK product information states that no significant effects on milk ejection were reported during clinical studies, and that any carbetocin ingested by a breast-fed infant would probably be degraded by enzymes in the gastrointestinal tract. The American Academy of Pediatrics considers that the use of carbetocin is usually compatible with breast feeding.2
1. Silcox J, et al. Transfer of carbetocin into human breast milk. Obstet Gynecol 1993; 82: 456–9
2. American Academy of Pediatrics. The transfer of drugs and other chemicals into human milk. Pediatrics 2001; 108: 776–89. Correction. ibid.; 1029. Also available at: pediatrics%3b108/3/776 (accessed 30/06/08)

💊 Interactions

Although reports are lacking, carbetocin may be involved in similar interactions to those that can occur with oxytocin.

💊 Pharmacokinetics

After intravenous injection of carbetocin, firm uterine contraction occurs within 2 minutes and lasts for several hours. Carbetocin undergoes a biphasic elimination, with a terminal elimination half-life of about 40 minutes. Less than 1% of a dose is excreted unchanged by the kidney. Carbetocin is distributed into breast milk.

💊 Uses and Administration

Carbetocin is a synthetic analogue of oxytocin reported to have a longer duration of action. For the prevention of uterine atony and excessive bleeding after caesarean section under epidural or spinal anaesthesia, a single dose of 100 micrograms may be given by slow intravenous injection over 1 minute. Carbetocin must only be given after delivery of the infant, preferably before removal of the placenta.
1. Hunter DJS, et al. Effect of carbetocin, a long-acting oxytocin analog on the postpartum uterus. Clin Pharmacol Ther 1992; 52: 60–7
2. Dansereau J, et al. Double-blind comparison of carbetocin versus oxytocin in prevention of uterine atony after cesarean section. Am J Obstet Gynecol 1999; 180: 670–6
3. Boucher M, et al. Comparison of carbetocin and oxytocin for the prevention of postpartum hemorrhage following vaginal delivery: a double-blind randomized trial. J Obstet Gynaecol Can 2004; 26: 481–8
4. Leung SW, et al. A randomised trial of carbetocin versus syntometrine in the management of the third stage of labour. BJOG 2006; 113: 1459–64.

💊 Preparations

Proprietary Preparations

Arg.: Duratocin; Austral.: Duratocin; Canad.: Duratocin; Fr.: Pabal; Hong Kong: Duratocin; Hung.: Pabal; Malaysia: Duratocin; Mex.: Lonactene; Port.: Pabal; Singapore: Duratocin; UK: Pabal. Multi-ingredient: Cz.: Duratocin.
Published October 13, 2018.