Is Lamotrigine safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Lamotrigine. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
One infant was exclusively breastfed from day 2 of life during maternal lamotrigine 300 mg daily, which was decreased at 6 weeks postpartum to 200 mg daily and 50% formula was introduced. Examinations every 4 weeks showed normal development and no evidence of intellectual disabilities or neurologic deficits. An electroencephalogram at 4 weeks of age showed no signs of pathology.[ 3 ] A breastfed infant whose mother was taking lamotrigine 300 mg daily during pregnancy and postpartum had no observable adverse effects up to 5 months of age.[ 4 ] The same authors reported 9 previously unreported infants who were breastfed during maternal lamotrigine therapy (dosage range 100 to 800 mg daily) with no adverse effects.[ 6 , 7 ] Thirty-five pregnancies in 34 mothers who were taking lamotrigine during pregnancy were monitored. An unstated fraction of them breastfed their infants. No adverse effects in infants were observed.[ 5 ] An exclusively breastfed infant whose mother was taking lamotrigine 200 mg and levetiracetam 2.5 g daily during pregnancy and lactation appeared healthy to the investigators throughout the 6- to 8-week study period.[ 29 ] The breastfed infant of a woman taking lamotrigine 300 mg daily developed normally during the first 4 months of life and no adverse effects were observed.[ 30 ] A 6-week-old infant developed apparent withdrawal symptoms after abrupt weaning by a mother who was taking lamotrigine 200 mg daily during late pregnancy and postpartum. Symptoms included loss of appetite, neuromotor hyperexcitability and irritability. Symptoms occurred 2 weeks after weaning and were completely alleviated within 48 hours after instituting lamotrigine 1 mg/kg daily in the infant. Neuromotor development of the infant normalized 1 month after discontinuing therapy.[ 31 ] The reaction is rated as probably caused by lamotrigine in breastmilk. The Berlin Teratogen Information Service evaluated 61 infants exposed to lamotrigine in breastmilk (46 prospectively and 1
Effects on milk supply
Relevant published information was not found as of the revision date.
Levels in milk
In published reports of anticonvulsant use during breastfeeding, most women were taking a combination of anticonvulsants. Some other anticonvulsants (e.g., phenytoin, carbamazepine) stimulate the metabolism of other drugs including anticonvulsants, whereas others (e.g., valproic acid) inhibit the metabolism of other drugs. Therefore, the relationship of the maternal dosage to the concentration in breastmilk can be quite variable, making calculation of the weight-adjusted percentage of maternal dosage less meaningful than for other drugs in this database. Maternal Levels. An epileptic woman took oral lamotrigine 300 mg daily throughout pregnancy and postpartum. After 6 weeks postpartum, the dosage was reduced to 200 mg daily. Breastmilk lamotrigine levels (time with respect to the doses not stated) on a dose of 300 mg daily ranged from 2.4 to 6.5 mg/L. After reducing the maternal dosage to 200 mg daily, the milk levels were 1.95 and 1.26 mg/L at days 64 and 92 postpartum, respectively.[ 3 ] A woman with epilepsy was taking lamotrigine at a dosage of 300 mg daily in the last half of pregnancy and postpartum. At 2 weeks postpartum, breastmilk samples taken before the morning dose, before and after nursing, were 5.6 and 5.7 mg/L, respectively.[ 4 ] Thirty-four women with 35 births had breastmilk lamotrigine levels monitored. Specific dosages and milk levels were not reported in the abstract, but the authors stated that they calculated that some of the infants received an mg/kg dosage that would be expected to produce therapeutic serum levels. However, infant serum levels were not reported.[ 5 ] Nine mothers with epilepsy mothers with 10 pregnancies taking lamotrigine in daily dosages averaging 411 mg daily (range 100 to 800 mg daily) had their breastmilk lamotrigine levels monitored between days 13 and 18 postpartum before and after nursing. (One of the mothers had her first of 2 pregnancies reported previously in reference [ 2 ]) Three of the women were also taking oth
Alternatives LactMed lists
Source: NIH LactMed (National Library of Medicine).
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.