Erenumab and Breastfeeding

Summary of use during lactation

No information is available on the passage of erenumab into breastmilk. Because erenumab is a large protein molecule with a molecular weight of 150,000 Da, the amount in milk is likely to be very low.[1] It is also likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal.[2] Two infants have been breastfed during maternal erenumab therapy without any adverse effects. Until more data become available, erenumab injection should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant. Waiting for at least 2 weeks postpartum to resume therapy may minimize transfer to the infant.[3]

Drug levels in milk and infant serum

Maternal Levels. Relevant published information was not found as of the revision date. Infant Levels. Relevant published information was not found as of the revision date.

Effects in breastfed infants

A postpartum woman who was nursing her 21-month-old infant twice daily had chronic migraine unresponsive to conventional treatment. Erenumab was begun at a dose of 70 mg (presumably subcutaneously once monthly). The mother noted no adverse effects in the infant over the following 5 months. The infant developed adequately, and each of seven mandatory childhood check-ups was normal. No infections occurred, and no problems with nutrition were noted.[4] A woman with a long history of migraine received subcutaneous erenumab 70 mg monthly during pregnancy and postpartum. After delivery, she partially breastfed her infant in an unspecified proportion of breastmilk. The mother was told the baby was meeting normal developmental milestones at visits with the baby’s pediatrician. At the 6-month pediatrician visit, the baby’s weight was 8.15 kg (80th percentile), height 71.8 cm (>95th percentile), and head circumference 43.2 cm (75th percentile).[5] A review of the database of reports of suspected adverse reactions maintained by the World Health Organization identified one report of an infant who experienced poor feeding during maternal use of erenumab. No further details were provided.[6]

Effects on lactation and breastmilk

Relevant published information was not found as of the revision date.

Alternative drugs to consider

(Migraine Prophylaxis) Divalproex, Metoprolol, Nortriptyline, Propranolol, Rimegepant, Topiramate, Valproic Acid

References

1. Stratigakis A, Paty D, Zou P, et al. A regression approach for assessing large molecular drug concentration in breast milk. Reprod Breed 2023;3:199-207. doi:10.1016/j.repbre.2023.10.003
2. Anderson PO. Monoclonal antibodies during breastfeeding. Breastfeed Med 2021;16:591-3.33956488 PubMed
3. Krysko KM, Dobson R, Alroughani R, et al. Family planning considerations in people with multiple sclerosis. Lancet Neurol 2023;22:350-66.36931808 PubMed
4. Henze T. Erenumab during breastfeeding. Breastfeed Med 2019;14:513-4.31381367 PubMed
5. Vig SJ, Garza J, Tao Y. The use of erenumab for migraine prophylaxis during pregnancy: A case report and narrative review. Headache 2022;62:1256-63.35467013 PubMed
6. Noseda R, Bedussi F, Gobbi C, et al. Safety profile of erenumab, galcanezumab and fremanezumab in pregnancy and lactation: Analysis of the WHO pharmacovigilance database. Cephalalgia 2021;41:789-98.33435709 PubMed