Is it safe to breast-feed when treated with lamotrigine and vigabatrin?/nThe question concerns a wo

Fråga: Is it safe to breast-feed when treated with lamotrigine and vigabatrin?

The question concerns a woman, treated with vigabatrin (Sabrilex) 1.5 g/day and lamotrigine (Lamictal) 600 mg/day, who has a newborn baby.

Sammanfattning: Lamotrigine is excreted into considerable amounts in breast-milk. Data on vigabatrin is sparse. Breast-feeding during treatment with both lamotrigine and vigabatrine is not recommended.

Svar: Questions about lamotrigine and breast-feeding have been answered in Drugline several times (1,2,3). It has been concluded that lamotrigine is transferred into breast milk in considerable amounts (up to 20% of the weight-adjusted dose) (4) and plasma concentrations up to 50% of maternal concentrations have been measured in the infant. Since lamotrigine is glucuronated in the liver, a process that is very slow in children, a risk for accumulation exists. However, no adverse effects in exposed infants have been observed (1,2,3).

One new publication concerning lamotrigine and breast-feeding has been found. The serum levels in four infants, whose mothers were treated with lamotrigine in monotherapy, were analysed. One baby had an undetectable level, whereas the other three had lamotrigine levels ranging from 20 to 43% of the maternal level. No decline was seen in two children after two months (5).

Concerning vigabatrin, only one published article was found. The concentrations of the two vigabatrin enantiomers were measured in the breast-milk of two patients during steady-state. The weight-adjusted dose the infants received was calculated to be 2.0-3.6% of the inactive R-enantiomer and 0.6-1% of the active S-enantiomer (6). Vigabatrin has some potentially severe side effects, such as visual field defects (7). The relevance of fetal and lactational exposition is unknown.