Excreted in very low levels into breast milk. Commonly used for pediatric treatment of small babies; it is very well tolerated by infants. Erythromycin is a macrolide that has been related to hypertrophic pyloric stenosis after early exposition through the breast milk. Avoiding its use in the first post-partum month would be a cautious measure. Be aware of the possibility of false negative results of bacterial cultures when the mother is on antibiotics. Also, diarrheal disease due to imbalance of intestinal flora is possible Small doses used for treatment of dermatologic and ophthalmologic conditions, together with a very low level in the mother’s plasma make very unlikely a significant excretion into breast milk. Topically used Erythromycin is safe while breastfeeding. Systemic treatments would be safer after the first month of life. The American Academy of Pediatrics rates it usually compatible with breastfeeding. List of Essential Medicines WHO 2002: Compatible with breastfeeding.