TreatAllergies.com

It is best to be cautious about taking antihistamines while breast-feeding. Most antihistamines represent only a minimal risk to a breastfeeding mother and child, and antihistamines that are taken nasally rather than orally have even less chance of being transferred to a mother's milk. Antihistamines can possibly reduce milk production because antihistamines tend to decrease bodily secretions and could result in an infant becoming drowsy if the medications pass into the breast milk, even if the amount present is only about 1% of the adult dosage. It is not recommended that babies be exposed to antihistamines because they are more susceptible to the side effects, including irritability or overexcitement, but it is not known whether second generation antihistamines cetirizine or loratadine share these side effects. The safe use of loraratine, for example, has not been established during pregnancy, lactation or in infants under one year of age. Antihistamines should not be taken in the early postpartum weeks or by mothers who already have a compromised milk supply.