Levetiracetam concentrations in serum and in breast milk at birth and during lactation.

PURPOSE: To study the pharmacokinetics of levetiracetam (LEV) at birth, during lactation, and in the nursed infant.

METHODS

Eight consecutive breast-feeding women with epilepsy treated with LEV twice daily and their infants were studied.

RESULTS

The mean umbilical cord serum/maternal serum ratio was 1.14 (range, 0.97-1.45) (n = 4). The mean milk/maternal serum concentration ratio was 1.00 (range, 0.76-1.33) at 3 to 5 days after delivery (n = 7). At sampling 2 weeks to 10 months after delivery (n = 5), it was similar (range, 0.85-1.38). At 3 to 5 days after delivery, the infants had very low LEV serum concentrations (<10-15 microM), a finding that persisted during continued breast-feeding. No malformations were detected, and in none of the infants did signs of adverse effects develop.

CONCLUSIONS

Our data indicate an extensive transfer of LEV from mother to fetus and into breast milk. However, breast-fed infants had very low LEV serum concentrations, suggesting a rapid elimination of LEV.