BACKGROUND AND PURPOSE:

• There is no clear consensus on the safety of antiepileptic drugs (AEDs) during breastfeeding due to limited data of medication levels in breast milk
• Birnbaum et al. (JAMA Neuro., 2019) sought to determine the extent of AED exposure via breastfeeding

METHODS:

• Prospective cohort study (2012 to 2016)
  • Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs [MONEAD] observational multicenter study
• Participants
  • Mothers: Epilepsy diagnosis | 14 to 45 years | <20 weeks | IQ scores >70 points
  • Infants: Enrolled at birth
• Exposures
  • AED exposure in infants who were breastfed
• Study design
  • Women followed up through pregnancy and 9 months postpartum
  • Children followed up until 6 years of age
  • AED concentrations from infants and mothers at the same visit, 5 to 20 weeks after birth
  • AEDS: Carbamazepine | Carbamazepine-10,11-epoxide | Levetiracetam | Lamotrigine | Oxcarbazepine | Topiramate | Valproate | zonisamide
  • infant values < plasma-equivalent lower limits of quantification (LLoQ) were represented as half of LLoQ
  • Breastfeeding measurements: Total duration of overall daily breastfeeding sessions | Volume of pumped breast milk (bottle)
• Primary outcome
  • The percentage of infant-to-mother concentration of AED

RESULTS:

• 164 matching infant-mother concentration pairs
• 49% of all antiepileptic drug concentrations in nursing infants were less than the lower limit of quantification
• Median percentage of infant-to-mother concentration
  • Ranged from 0.3% (carbamazepine epoxide) to 44.2% (Zonisamide)
• Maternal concentration association with infant concentration  
  • Lamotrigine concentration was associated with infant concentration (P < 0.001)
  • Levetiracetam concentration was not associated with infant concentration
  • Analysis only done for these 2 AEDs, because there were not enough infant samples that were >LLoQ for the other AEDs  

CONCLUSION:

• Overall, AED concentrations in blood samples of breastfed infants were much lower than that of their mothers
• For carbamazepine, oxcarbazepine, valproic acid, levetiracetam, and topiramate, infant levels were less than respective LLoQs
• The authors of this study conclude that their findings support the continued breastfeeding of infants by mothers receiving AEDs
  • The benefits of breastfeeding are very well established
  • Previous studies have not shown adverse effects when the mother was receiving AEDs

Learn More – Primary Sources:

Antiepileptic Drug Exposure in Infants of Breastfeeding Mothers With Epilepsy

Related ObG Topics:

Antiepileptic Drugs: What is the Impact on Risk for Birth Defects

Adverse Perinatal Outcomes and Epilepsy: Is it the Disorder or the Treatment?

Antiepileptic Medications and Risk for Congenital Malformations