Risks to the infant
Infants whose mothers receive lamotrigine, have elevated levels of this medicine in their blood and can reach 50% of that of the mother, but most often ranging between 30 and 35% of this. During the neonatal period, the risk is even higher due to the limited capacity of elimination by conjugation with glucuronic acid, which, together with the risk of elevated maternal levels in the immediate postpartum period, can produce strong effects if not decreased lamotrigine dose to the mother after delivery .
Lamotrigine passes to the fetus through the placenta. An exclusively breastfed infant, from the second day reached this same day a blood level of 2.8 ng/ml (free fraction: 1.2 ng/ml). By reducing the maternal dose to 200 mg from 300 mg previously received, the levels fell to 0.75-1.54 ng / ml . In a two-week baby, levels were 1.4 ng/ml before taking the medicine in the morning .
In a group of 10 infants whose mothers received lamotrigine during pregnancy and continued to do so after delivery, drug levels were similar to the mother immediately postpartum, descending slowly over the next three days. After three weeks, reached levels between 0.5 and 3.3 ng/ml at twelve hours of the last dose of lamotrigine and before the corresponding feeding, these children showed values ??between 23 and 50% of maternal .
No effects were observed on a breastfed infant whose mother received 300 mg/day for the first six weeks and 200 mg/day from that moment . Another infant in similar circumstances not presented anomalies during the monitoring carried out until the 5th month of life. Nine other cases also showed no adverse effects. Part of thirty-five pregnant patients taking lamotrigine during pregnancy and breastfed their children, not observed adverse effects in their babies . An infant whose mother jointly received 200 mg of lamotrigine, and 2.5 g of levetiracetam per day showed not alteration for a period of eight weeks follow-up .
An infant six weeks showed a withdrawal two weeks after weaning. Baby manifested by loss of appetite, irritability and hyperexcitability neuromotor, disappearing after administration of the drug . Psychomotor development was normal one month after the final suspension of the drug. Two infants whose mothers received lamotrigine showed moderate psychomotor retardation objectified by the Denver test .
Influence on lactation
There are no known direct effects of lamotrigine on breastfeeding.
In cases published about lamotrigine concentration in breast milk, there have been levels between 2.4 and 6.5 ng/ml in dosing regimens of 300 mg daily. Decreasing the dose to 200 mg/day these values ??fall to 1.26-1.95 ng/ml .
In a study that included nine women whose doses ranged from 100 to 800 mg/day, is reached in milk concentrations between 1 and 8.2 ng/ml at twelve hours of the previous dose. The authors believe that infants exclusively fed with breast milk received 0.2-1 mg / kg (2-20% of the maternal dose adjusted by weight).
If a mother requires the administration of lamotrigine during breastfeeding, it is not sufficient reason to abandon or discontinue breastfeeding, since many infants have been breastfed without presenting secondary reactions despite high blood levels achieved. However, it is important to stress that these babies should be monitored closely for early detection of potential adverse effects, including rashes that are potentially dangerous as well as drowsiness, refusal of food or unjustified loss of appetite. Must be prevented the risk of withdrawal syndrome and warn the mother of the danger of abrupt weaning and asses the possible administration of other antiepileptic drugs that may interfere with the metabolism of lamotrigine.
1.Ohman I, Vitols S, Tomson T. Lamotrigine in pregnancy: pharmacokinetics during delivery, in the neonate, and during lactation. Epilepsia. 2000; 41:709-13.
2. Liporace J, Kao A, D'Abreu A. Concerns regarding lamotrigine and breast-feeding. Epilepsy Behav. 2004; 5:102-5.
3. Rambeck B, Kurlemann G, Stodieck SRG et al. Concentrations of lamotrigine in a mother on lamotrigine treatment and her newborn child. Eur J Clin Pharmacol. 1997;51:481-4.
4. Tomson T, Ohman I, Vitols S. Lamotrigine in pregnancy and lactation: a case report. Epilepsia. 1997;38:1039-41.
5. Ohman I, Tomson T, Vitols S. Lamotrigine (LTG) pharmacokinetics during delivery and lactation. Ther Drug Monit. 1999;21:478.
6. Berry DJ. The disposition of lamotrigine throughout pregnancy. Ther Drug Monit. 1999;21:450.
7. Johannessen SI, Helde G, Brodtkorb E. Levetiracetam concentrations in serum and in breast milk at birth and during lactation. Epilepsia. 2005;46:775-7.
8. Popescu L, Marceanu M, Moleavin I. Withdrawal of lamotrigine caused by sudden weaning of a newborn: a case report. Epilepsia . 2005;46 (Suppl 6):407.
Warning of the manufacturer:
Available data indicate that lamotrigine passes into breast milk. In a study conducted in a limited number of infants fed with breast milk, serum concentrations of lamotrigine in children reached levels at which pharmacological effects may occur.
Be assessed the potential benefit of breastfeeding against the risk of harm to the newborn. If a woman decides to breast-feed during treatment with lamotrigine, it should monitor the occurrence of adverse effects on the newborn.