Doctors often tell new mothers to stop taking medications while breastfeeding to protect the infants, but this may not be needed, U.S. researchers say. Hari Cheryl Sachs of Rockville, Md., said many mothers are inappropriately advised to discontinue breastfeeding or avoid taking essential medications because of fears of adverse effects on their infants. This cautious approach may be unnecessary in many cases, because only a small proportion of medications are contraindicated in breastfeeding mothers or associated with adverse effects on their infants, Sachs said. Previous statements on this topic from the American Academy of Pediatrics provided physicians with data concerning the known excretion of specific medications into breast milk. More current and comprehensive information is now available on the Internet, as well as an application for mobile devices, at LactMed at: toxnet.nlm.nih.gov. Therefore, with the exception of radioactive compounds requiring temporary cessation of breastfeeding, the reader will be referred to LactMed to obtain the most current data on an individual medication, the study said. This report discusses several topics of interest surrounding lactation, such as the use of psychotropic therapies, drugs to treat substance abuse, narcotics and herbal products, as well as immunization of breastfeeding women. The findings are published online ahead of the print edition of Pediatrics.