Antihistamine drug of 2nd generation, piperidine derivative, which is an active metabolite of Terfenadine with minimal sedative effect. Oral administration twice a day. It is excreted into breast milk in clinically non-significant amount (Butler 2014, So 2010, Leachman 2006, Lucas 1995). On a telephone interview, 10% of infants whose mothers were on terfenadine, recognized to have experienced colicky pain and hyperexcitability that disappeared without treatment (Ito 1993). American Academy of Pediatrics: medication usually compatible with breastfeeding (AAP 2001).