I was told by a pharmacist, knowledgeable about drugs and breastfeeding, that Seldane is a long acting antihistamin with a very long half-life which would make it more likely to accumulate in the breastfed infant. This pharmacist suggested that shorter acting antihistamins be used by a BF mom. Dany Gauthier IBCLC [log in to unmask] Tel: 514-923-3792 Fax:514-923-3802