Second generation antihistamine drug derived from piperazine with a minimal sedative effect and low toxicity even at higher dose. On latest update no published data about breastfeeding were found. However, it is the R-enantiomer of cetirizine which is considered to be safe while breastfeeding. No short or long-term side effects were found in an infant with a mother who was treated with Cetirizine in the first month post delivery for pemphigus (Westermann 2012). Because of a high plasma protein binding capacity, excretion into breast milk seems to be unlikely. The British Society of Immunology and Allergy rates Cetirizine as compatible with breastfeeding (Powell 2007).