Levetiracetam Concentrations in Serum and in Breast Milk at Birth and during Lactation

Summary: 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 μM), 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.