Active substance is loratadin (antihistaminic). It has a long half live. As
far as I know, there is only one study on it, with women who have taken a
single dose of 40 mg ; ratio milk/plasma was 0,6-1,2, and the baby was
taking at most 17,4 µg/kg/day of active substance. There is no study on how
it passes into breast milk with a long treatment. Long half live gives
possibility of accumulation in breast milk.

It is used here in pediatric. Posology between 2 to 12 years : 5-10 mg/day.

Possible to use another drug. Ceterizin and terfadin are said to be a
better
choice for a breastfeeding mother.

Kindly
Françoise Railhet
LLL France Medical Associates Program