OnabotulinumtoxinA and Breastfeeding

Summary of use during lactation

OnabotulinumtoxinA was not detectable in the milk of two women and detectable in only minute amounts in 5 others after 40 to 92 units injected into the face. An international guideline considers onabotulinumtoxinA acceptable in breastfeeding women with chronic migraine.[1] One infant was safely breastfed during maternal botulism, and no botulinum toxin was detectable in the mother's milk or infant. Breastfeeding appears to protect infants against botulism.[2] No special precautions are required.

Drug levels in milk and infant serum

Maternal Levels. Type A botulinum toxin was detected in the blood and stools of a nursing mother after ingesting fermented salmon eggs. She was given 2 vials of trivalent botulism antitoxin, 1 intravenously and 1 intramuscularly. A milk sample obtained 3 days after the onset of her illness and 4 hours after administration of botulinum antitoxin had no detectable botulinum toxin nor botulism organisms.[3] Four women undergoing cosmetic procedures were injected with doses ranging from 40 to 92 units of onabotulinumtoxinA. Milk samples were taken at baseline and 1, 3 and 5 hours after the injections. Two women had undetectable (<46 ng/L) levels in all samples after receiving 54 and 92 units. Two other women who received 40 and 46 units had peak milk levels of 422 ng/L and 747 ng/L, respectively.[4] In a preprint, 3 women were reported who received onabotulinumtoxinA at 3 sites for facial cosmetic procedures for a total dose of 64 units. They were instructed to express 200 mL of breastmilk before treatment and 1, 6, 24, 36, 48, and 72 hours after treatment using a manual pump. In addition, milk samples were collected at 5, 6, 7, 10, and 11 days, 2 months, 4 months, and 5 months after the injections. The highest observed concentration was 33.4 ng/L in in one woman 4 days after the injection. In another woman, the highest concentration occurred 3 days after the injection. After the first week, milk concentrations in one woman decreased to a low of 6.9 ng/L at 11 days, before another peak of 26.6 ng/L at 2 months after the injections. If the highest concentration and a dose of 150 mL/kg daily breastmilk intake are used, a breastfed infant would receive a maximum of 5 ng/kg of botulinum toxin A orally per day, which is far below the dose of 12 to 25 units/kg given by injection to children with spastic cerebral palsy.[5] Infant Levels. Type A botulinum toxin was detected in the blood and stools of a nursing mother after ingesting fermented salmon eggs. No botulinum toxin was detected in the breastfed infant's blood or stool on the day the mother was admitted to the hospital (3 days after the onset of illness) and no botulism organisms were detected in the infant's stools.[3]

Effects in breastfed infants

One mother breastfed her infant while she was experiencing toxicity from botulism poisoning. She breastfed her 2-month-old infant. Although the mother died, the infant had no symptoms.[6] A woman developed botulism after ingesting fermented salmon eggs while breastfeeding her 8-month-old breastfed (extent not stated) infant. The infant developed no signs or symptoms of botulism even though she continued to nurse throughout the mother's hospitalization.[3]

Effects on lactation and breastmilk

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

Alternative drugs to consider

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

References

1. Puledda F, Sacco S, Diener HC, et al. International Headache Society Global Practice Recommendations for Preventive Pharmacological Treatment of Migraine. Cephalalgia 2024;44:3331024241269735.39262214 PubMed
2. Arnon SS, Damus K, Thompson B, et al. Protective role of human milk against sudden death from infant botulism. J Pediatr 1982;100:568–73.7038077 PubMed
3. Middaugh J. Botulism and breast milk. N Engl J Med 1978;298:343.622098
4. Hudson C, Wilson P, Lieberman D, et al. Analysis of breast milk samples in lactating women after undergoing botulinum toxin injections for facial rejuvenation: A pilot study. Facial Plast Surg Aesthet Med 2024;26:523–6.38306172 PubMed
5. Gu H, Xu Z, Koviazina R, et al. Detection of nontoxic BoNT/A levels in post-facial botox injection breastmilk using a multi-technique approach. bioRxiv 2024. doi:10.1101/2024.05.22.595434
6. Douthirt C. An outbreak of botulism in Tucumcari, New Mexico. Southwest Med 1938:51–3.