But so - called first - generation antihistamines such as diphenhydramine (Benadryl) and chlorpheniramine (Chlor - Trimeton) can potentially cause sedation in your baby (just as they can in you), while the second - and third - generation medications such as loratadine (Claritin) and fexofenadine (Allegra) are less likely to. (babycenter.com)
Data has shown that small doses of loratadine, if used as instructed, will only allow a miniscule quantity of it into breast milk, which is unlikely to pose any effects on a baby. (newkidscenter.com)
When choosing an antihistamine, breastfeeding moms should choose a non-sedating variety which contains loratadine. (newkidscenter.com)