Small occasional doses of azelastine nasal spray would not be expected to cause any adverse effects in breastfed infants. Larger doses or more prolonged use of the nasal spray may cause drowsiness and other effects in the infant or decrease the milk supply, particularly in combination with a sympathomimetic such as pseudoephedrine or before lactation is well established. Infant rejection of the breast might occur because of the bitter taste of the drug. The oral, nonsedating antihistamines are preferred alternatives.
Because absorption from the eye is limited, azelastine would not be expected to cause any adverse effects in breastfed infants. To substantially diminish the amount of drug that reaches the breastmilk after using eye drops, place pressure over the tear duct by the corner of the eye for 1 minute or more, then remove the excess solution with an absorbent tissue.