Many commonly used antiseizure medications (ASMs) have data supporting their use as single agents in lactating individuals. Prospective observational studies, including the Maternal Outcomes and Neurodevelopmental Effects of Antiepileptic Drugs (MONEAD) trial, assessed the effect of breastfeeding on IQ in children of women taking ASMs (carbamazepine, lamotrigine, phenytoin, and valproate) at both 3 years and 6 years of age. No negative effects on cognitive function were found in either age group. In fact, the breastfed children had higher IQs and higher verbal development at 6 years (1, 2). There is also evidence that fetal exposure to ASMs may impact fine motor and social development and breastfeeding may help decrease these prenatal effects of ASMs due to the neuro-protective and neuro-maturation qualities of human milk (1,3).

Long-term outcomes with other ASMs and the many possible medication combinations have not been well studied. Additionally, breastfed infants, particularly those who are premature or small for gestational age, should be closely monitored for side effects including rashes, apnea, drowsiness, and adequate weight gain. Developmental milestones should be monitored for all infants exposed to ASMs. Routinely measuring infant medication levels is not necessary.

Some medications, such as phenobarbital, primidone and long-acting benzodiazepines,  have a higher milk transfer. Because these medications are associated with a greater risk for side effects, partial human milk feeding can be considered to mitigate this risk (1).

For more detailed information and references on specific medications, please refer to LactMed, e-lactancia, Infant Risk, or Mother to Baby.

Benzodiazepines (ex: clonazepam/Klonopin, diazepam/Valium) are commonly used to manage acute seizures and status epilepticus. These medications should be used with caution with close monitoring of the breastfed infant for sedation, poor feeding, and/or decreased respiration. Agents with shorter half-lives and lower milk transfer are preferred.

• Lorazepam/Ativan: Lorazepam has low milk transfer, a relatively short half-life compared to other benzodiazepines, and is used in the direct treatment of infants. Available data from a few small studies suggest breastfed infants do not have side effects with use of this medication during lactation. However, infants should be closely monitored for side effects such as sedation, poor feeding, and decreased respiration. There is no absolute indication to pump and dump.
• Oxazepam/Serax: Oxazepam has low milk transfer and a relatively short half-life compared to other benzodiazepines. While data on infant side effects of this medication are limited, the risk for side effects seems to be low based on available pharmacologic properties of this medication. Infants should be monitored for side effects given the lack of data while using this medication, but there is no absolute indication to pump and dump.
• Clobazam/Onfi: Clobazam has a longer half-life with a greater risk for infant side effects compared to other benzodiazepines. Infants should be closely monitored for sedation, poor feeding, and delays in developmental milestones (especially in younger infants, exclusively breastfed infants, or breastfed infants of lactating parents on multiple psychotropic medications). Alternatives are preferred due to clobazam’s long half-life. If this medication is given in infrequent low doses, there is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking clobazam.
• Clonazepam/Klonopin: Clonazepam, like clobazam, has a longer half-life with a greater risk for infant side effects compared to other benzodiazepines . Infants should be closely monitored for sedation, poor feeding, and delays in developmental milestones (especially in younger infants, exclusively breastfed infants, or breastfed infants of lactating parents on multiple psychotropic medications). Alternatives are preferred due to clonazepam’s long half-life. If this medication is given in infrequent low doses, there is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking clonazepam.
• Diazepam/Valium: Diazepam has significant milk transfer with a longer half-life. Its metabolite, nordiazepam, also has a long half-life. Timing breastfeeding around doses would have limited benefit to reduce the total infant exposure to this medication due to this long half-life. Breastfed infants (especially with newborns or preterm infants) should be closely monitored for hyperbilirubinemia, poor feeding, and sedation. A single higher dose of IV diazepam given perioperatively in the first few days after birth during lactation was associated with significant increase in hyperbilirubinemia and weight loss in a group of Asian neonates, although this effect was not seen with a 5mg oral dose of diazepam (4). Parents may consider waiting 6-8 hours after a higher one time dose to resume breastfeeding, especially if the lactating parent is on other psychoactive medications. While alternatives are preferred (particularly with newborn and premature infants) and infants should be closely monitored for side effects, there is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking diazepam.

There is limited information on the use of this medication during lactation so alternative medications are preferred.

There is limited information on the use of this medication during lactation so alternative medications are preferred. For more information, see the section on Cannabis.

Although carbamazepine’s active metabolite is found in relatively high concentrations in breastmilk, infant serum levels  are well below its anticonvulsant therapeutic window per multiple studies as well as the recently released MONEAD trial results (5). Infants should be monitored for side effects of this medication such as sedation, poor sucking, insufficient weight gain, jaundice, and liver abnormalities, especially if this medication is taken with other ASMs.

With regards to long term outcomes, the MONEAD trial results suggest that there are not negative long term neurodevelopmental outcomes with breastfeeding while on carbamazepine. When used as a single agent, long term follow-up showed there were no adverse neurodevelopmental outcomes in breastfed children compared to formula fed children at 6 years of age. In fact, children who were breastfed had slightly higher IQ and verbal scores (2).

It is reasonable to consider monitoring infant serum carbamazepine levels, liver enzymes and blood count. There is no absolute indication to pump and dump and parents should be engaged in shared decision making regarding the use of breastmilk while taking carbamazepine.

There is limited information on the use of this medication during lactation so alternative medications are preferred.

Little is known about divalproex, but it is quickly metabolized into the active drug valproic acid. Valproic acid levels are low in breast milk. The MONEAD trial results found no detectable valproate in the two breastfed infants in the study (5). There is a theoretical risk of liver damage in the infant with valproic acid use as well as one case report of thrombocytopenia  (low platelets) (6). Therefore, infants should be monitored for jaundice and abnormal bruising or bleeding. When valproic acid is used in combination with other sedating ASMs or psychotropic medications, the infant should be monitored for sedation.

With regards to long term outcomes, the MONEAD trial results suggest that there are no negative long term neurodevelopmental outcomes with breastfeeding while on valproate. When used as a single agent, there were no adverse neurodevelopmental outcomes in breastfed children compared to formula fed children at 6 years of age. In fact, children who were breastfed had slightly higher IQ and verbal scores (2).

While infants should be monitored for jaundice, bruising or bleeding, and sedation, there is no absolute indication to pump and dump. Patients should be engaged in shared decision making regarding the use of breastmilk while taking divalproex.

There is limited information on the use of this medication during lactation so alternative medications are preferred.

Ethosuximide has significant milk transfer with 50-60% or more of maternal weight-adjusted doses found excreted into milk. Infant plasma levels have been found to be 25-30% or more of maternal plasma levels as noted in LactMed. Data is limited on adverse effects of this medication in the breastfed infant when used as monotherapy, and infants should be closely monitored for side effects including drowsiness, poor weight gain, and delayed development especially if used with other agents. While there is significant milk transfer and infants should be monitored for side effects, there is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking ethosuximide.

Parents on felbamate should not breastfeed. Felbamate can cause fatal hematologic and hepatic toxicity in individuals taking this medication. There is no data on milk transfer or the use of this medication in lactation. Due to the nature of the possible side effects, infants should not breastfeed if their parent is on this medication.

Infants should be monitored for drowsiness and insufficient weight gain with chronic use of higher doses of gabapentin. Milk transfer does occur as low blood levels of gabapentin have been found in breastfed infants (7). While exposed infants should be closely monitored for side effects including sedation, poor feeding, and developmental delay, there is no absolute indication to pump and dump. Parents should be engaged in shared decision making  regarding the use of breastmilk while taking gabapentin.

Limited data suggests milk transfer is likely low. There are no reports of adverse events. While there is no absolute indication to pump and dump, alternatives are preferred due to the lack of data with the use of this medication. Parents should be engaged in shared decision making regarding the use of breastmilk while taking lacosamide, and infants should be monitored for sedation, poor feeding, and developmental delay.

While the MONEAD trial results published in 2020 noted that there are detectable levels of lamotrigine in many of the breastfed infants in that study (5), most infants are able to breastfeed without adverse reactions. There are rare case reports of adverse reactions as cited in LactMed including apnea, rash, drowsiness, and poor suckling. Preterm and newborn infants are at higher risk for these side effects. Breastfed infants should be closely monitored for side effects with measurement of infant serum levels of lamotrigine and interruption of breastfeeding  if signs of toxicity develop. If the lactating parent’s lamotrigine dose is increased, then it may be reasonable to monitor the breastfed infant’s platelet counts, liver function, and lamotrigine levels. Additionally, lamotrigine levels should be checked in lactating parents after delivery as lamotrigine doses often need to be reduced postpartum.

With regards to long term outcomes, the MONEAD trial results suggest that there are not negative long term neurodevelopmental outcomes with breastfeeding while on lamotrigine. When used as a single agent, long term follow-up showed there were no adverse neurodevelopmental outcomes in breastfed children compared to formula fed children at 6 years of age. In fact, children who were breastfed had slightly higher IQ and verbal scores (2).

While alternatives should be considered and infants should be closely monitored for side effects (anemia, neutropenia, apnea, drowsiness, poor feeding, and rash), there is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking lamotrigine.

Overall, adverse events in infants are rare with the use of levetiracetam and this medication is one of the most commonly used ASMs, as it is generally well tolerated among women in reproductive age (1). The MONEAD trial noted detectable levels of levetiracetam in 29% of breastfeeding infants with parents on this medication (5). There are reports of adverse effects in breastfed infants cited in LactMed including sedation, low tone, and poor feeding, mainly among individuals taking levetiracetam with other ASMs. There are professionals who have noticed low milk production among some lactating people taking levetiracetam. While milk production should be monitored and infants should be watched closely for side effects there is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking levetiracetam.

Data is limited with mixed information on milk levels. The MONEAD trial results only looked at 7 infants of parents on oxcarbazepine, but none of these infants had detectable levels of oxcarbazepine in their blood (5). There is one report of withdrawal symptoms shortly after birth in a newborn that improved with breastfeeding (8). While data is limited and adverse events are rare, infants should be monitored for side effects including drowsiness, irritability, and poor feeding. There is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking oxcarbazepine.

There is significant variability in the amount of phenobarbital excreted into breastmilk, even between samples from one individual. While breastfeeding may reduce the risk of neonatal withdrawal symptoms, breastfed infants are also at risk for side effects including drowsiness, poor feeding, and developmental delays, especially if phenobarbital is taken with other ASMs. Breastfed infants, particularly newborns and preterm infants, should be closely monitored (1). Infant phenobarbital levels may be measured if there are concerns for infant side effects, and the lactating parent should have their serum phenobarbital level monitored. While breastfed infants must be closely monitored, there is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking phenobarbital.

Phenytoin levels in breastmilk tend to be low as noted in multiple studies as cited in LactMed. Phenytoin as monotherapy is well tolerated based on available data. There is a case report of methemoglobinemia with the concurrent use of phenytoin and phenobarbital (1). Breastfed infants  should be monitored closely for side effects, including drowsiness, poor feeding, and methemoglobinemia, especially if used in combination with sedating or psychotropic agents.

With regards to long term outcomes, the MONEAD trial results suggest that there are no negative long term neurodevelopmental outcomes with breastfeeding while on phenytoin. When used as a single agent, long term follow-up showed there were no adverse neurodevelopmental outcomes in breastfed children compared to formula fed children at 6 years of age. In fact, children who were breastfed had slightly higher IQ and verbal scores (2).

There is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of milk from lactating individuals who are taking phenytoin.

Primidone is found in significant levels in breastmilk (1). As cited in LactMed, studies have shown that the use of primidone in lactating individuals can result in infant levels of primidone and its metabolites at or near the therapeutic range of this medication. Infant side effects may include sedation, poor feeding, and developmental delay. If there is a concern for infant side effects, it is recommended to check the infant serum level. Of note, if an infant is exposed in utero to primidone their risk of withdrawal may be lower with partial or exclusive breastfeeding, assuming the parent is still taking the medication. Additionally, if a breastfeeding infant needs to be weaned, they should be weaned gradually and monitored closely for withdrawal symptoms. While breastfed infants of lactating individual on this medication should be closely monitored for side effects  there is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking primidone.

Breastfed infants should be monitored for drowsiness, poor feeding, and developmental with the use of pregabalin. Low blood levels of pregabalin have been found at 48 hours postpartum in breastfeeding newborns whose mothers were taking this medication during pregnancy and postpartum. Alternatives are preferred due to the lack of data (7) and breastfed infants should be closely monitored for side effects, but there is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking pregabalin.

Doses of up to 200  mg daily in lactating individuals are associated with relatively low levels of this medication in the breastfed infant. The MONEAD trial results found no detectable topiramate in the two breastfed infants in the study (5). There have been rare case reports of sedation and diarrhea in breastfed infants as cited in LactMed. As with other ASMs, breastfed infants should be monitored for sedation, poor feeding, and developmental delays. Two studies noted no long-term adverse effects on growth and development in six infants (9, 10). There is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking topiramate.

Maternal doses of vigabatrin leads to low levels in milk. This medication is approved for infants as young as 1 month of age, and milk levels are much lower than the levels achieved by therapeutic infant doses. Vigabatrin is not expected to cause significant adverse infant side effects. There is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of breastmilk while taking vigabatrin.

Zonisamide doses up to 400 mg daily are associated with high milk and infant serum levels of this medication based on the studies cited in LactMed. The 2020 results published from the MONEAD trial found detectable levels of zonisamide in two out five breastfed infants (5). Of note, infant serum levels decline during the first month of life. Although no adverse infant side effects  have been reported, breastfed infants, especially those who are premature or very young, should be monitored closely for side effects including drowsiness, poor weight gain, and developmental delay, especially when more than one ASM is taken. Partial breastfeeding or mixed feeding may be more appropriate and infant serum concentrations of zonisamide may be monitored if there are concerns for adverse events or the infant is high risk. While alternatives are preferred due to the lack of data, and infants should be monitored closely for side effects due to the relatively high relative infant dose (RID), there is no absolute indication to pump and dump. Parents should be engaged in shared decision making regarding the use of milk from lactating individuals who are taking zonisamide.