Transfer of metaclazepam and its metabolites into breast milk.

Ten young women took part in this study a few days after delivery (day 3 and day 5 post partum). Lactation had developed normally but the newborn infants were not breast-fed. The study was intended to investigate whether metaclazepam (Talis), a new 1,4-benzodiazepine, and some of its metabolites were present in breast milk. Levels were measured in the plasma and milk. The levels in the milk showed that metaclazepam, N-desmethylmetaclazepam and two of its metabolites with a lactam structure could be found in small amounts. Differences in metaclazepam and N-desmethylmetaclazepam concentrations in the breast milk on days 3 and 5 post partum are discussed.