Antiepileptic Drug Concentrations Lower In Infants Than Mothers

Angela K. Birnbaum, PhD, FAS, Professor, Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy

Angela K. Birnbaum, PhD, FAS

Recently published results from MONEAD, a prospective cohort study, suggest that antiepileptic drug (AED) concentrations in the blood samples of breastfed infants were substantially lower than those in their mothers’ blood samples.

These results add support to the practice of breastfeeding in mothers with epilepsy who are on AED regimens given the benefits, author Angela K. Birnbaum, PhD, FAS, Professor, Department of Experimental and Clinical Pharmacology, University of Minnesota College of Pharmacy, and colleagues noted. The data add to other study findings which determined there were no ill effects to breastfeeding while on AEDs.

The study included 351 pregnant women and 345 infants, of which 64.3% (n = 222) were breastfed. All told, 42.3% (n = 146) had observable AED concentrations from visit 5 through 20 weeks post-birth. The median percentage of infant-to-mother concentration for 7 AEDS—carbamazepine, carbamazepine epoxide, lamotrigine, levetiracetam, oxcarbazepine, topiramate, valproic acid, and zonisamide&mdash;ranged from 0.3% to 44.2% in 164 infant-mother pairs. Those with mothers receiving lamotrigine therapy (52 pairs), infant concentrations (63 of 73 infants with concentration greater than the lower limit; median, 1.6 µg/mL [range, 0.05—8.5]) were associated with maternal concentrations (95 of 147 mothers with AED levels; median, 6.2 µg/mL [range, 1.4–9.9]; P <.001).

READ MORE: Breastfeeding Rates Are Lower Among Women With Epilepsy

“To our knowledge, this study provides direct information about AED drug exposure in the largest number of infants who were breastfed reported to date. Overall results indicate that AED drug exposure in infants, compared with their mothers who were taking AED therapy, is low,” Birnbaum and colleagues wrote.

Additionally, the group wrote that these findings might suggest why prior studies haven’t found adverse neurodevelopment effects of breastfeeding on AEDs. As such, these infants are expected to be followed until age 6 years to determine long-term outcomes.

“On the basis of infant exposure via breastfeeding from maternal AEDs, the results of this study add support to the general safety of breastfeeding by mothers with epilepsy who take AEDs,” Birnbaum et al wrote.

Recently, at the 73^rd annual meeting of the American Epilepsy Society (AES), December 6-10, 2019, in Baltimore, Maryland, data presented—including some from the MONEAD study&mdash;suggest that, despite the well-known benefits, women with epilepsy are less likely to breastfeed their children than those without epilepsy.^2,3

Analysis from the second study presented at AES 2019 revealed that 51% in the group with epilepsy (n = 102) compared to 87% in the control group (n = 113) breastfed postpartum. At 6 weeks and 3 months, those rates decline to 38.2% and 36.2% for those with epilepsy, respectively, and dropped even further to 18.6% at 6 months.³

Authors from both studies noted that this challenge is in part due to lack of education from non-specialist healthcare workers, who may be unfamiliar benefits and safety of breastfeeding in this patient population. Although, there were some data pointing positive with MONEAD also suggesting that the rates of exclusive breastfeeding were similar between groups, with 34.5% of those with epilepsy doing so compared to 28.6% of those without at 3 months.^1,2

Al-Faraj et al. detailed that reasons for not breastfeeding were only known in 17.6% of women. Those reasons included the fear of AED exposure through breast milk, recommendations by different providers (pediatricians and obstetricians) not to breastfeed, failed breastfeeding trials due to technical difficulties, and lack of milk supply.

The results also revealed that discussions regarding breastfeeding occurred by their attending neurologist for 52.9% of women with epilepsy, with 91% reporting their epilepsy nurse conducting the conversation. Of the 66% of those who received obstetrical care at Beth Israel Deaconess Medical Center, only 13% received lactation consultation prior to giving birth in comparison to 58% of the healthy cohort.

REFERENCES

1. Birnbaum AK, Meador KJ, Karanam A, et al. Antiepileptic Drug Exposure in Infants of Breastfeeding Mothers With Epilepsy. JAMA Neurol. Published online December 30, 2019. doi: 10.1001/jamaneurol.2019.4443.

2. Gerard E, Pennell P. Breastfeeding in women with epilepsy in the MONEAD study. Presented at: American Epilepsy Society 2019 Meeting; December 7—10; Baltimore, Maryland. Abstract 1.250.

3. Al-faraj A, Pang T. Factors affecting breastfeeding patterns in women with epilepsy. Presented at: American Epilepsy Society 2019 Meeting; December 7—10; Baltimore, Maryland. Abstract 1.246.