RimabotulinumtoxinB and Breastfeeding

Summary of use during lactation

No data exist on the medical use of rimabotulinumtoxinB during breastfeeding. However, it is not detectable systemically after intramuscular use, thus excretion into breast milk is considered unlikely. The closely related drug, 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. Many mothers have breastfed their infants after injection of onabotulinumtoxinA for migraine.[1] An international guideline considers onabotulinumtoxinA acceptable in breastfeeding women with chronic migraine.[2] No special precautions are required.

Drug levels in milk and infant serum

Maternal Levels. Published information on the medical use of rimabotulinumtoxinB during breastfeeding was not found as of the revision date. 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] 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.[4] 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.

References

1. Wong HT, Khan R, Buture A, et al. OnabotulinumtoxinA treatment for chronic migraine in pregnancy: An updated report of real-world headache and pregnancy outcomes over 14 years in Hull. Cephalalgia 2025;45:3331024251327387.40326040 PubMed
2. 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
3. Middaugh J. Botulism and breast milk. N Engl J Med 1978;298:343.622098
4. Douthirt C. An outbreak of botulism in Tucumcari, New Mexico. Southwest Med 1938:51–3.