Drugs in breast milk pose a potential risk to the breastfed infant, yet there has been a paucity of reliable safety information to guide physicians, other health care providers and mothers who want to breastfeed. As a consequence, many mothers discontinue breastfeeding unnecessarily.

To fill that information gap, the National Library of Medicine (NLM) launched the database Drugs and Lactation, or LactMed, in April 2006. LactMed responds to the increased prevalence of breastfeeding worldwide and an urgent call by the Centers for Disease Control and Prevention for accurate, current and accessible information on medication use during lactation.

LactMed contains more than 700 drug-specific records that provide known information about drug levels in breast milk; drug levels in infant plasma and urine; the effects of such exposure in breastfed infants and on lactation itself; and the AAP category indicating compatibility of the drug with breastfeeding. Also provided are a summary of use of the specified drug during lactation, potential alternative medications and references linked to their respective PubMed records.

LactMed is searchable by drug name (generic or trade), pharmacologic category, Chemical Abstracts Service Registry Number or subject terms (such as galactorrhea). A glossary and links to relevant breastfeeding organizations also are provided.

LactMed was developed by the NLM's Specialized Information Services Division in conjunction with a recognized authority on drugs and lactation, and a scientific review panel composed of physician experts in medication use during breastfeeding. The evidence-based content is derived from a comprehensive review of the world's published literature. The database is updated monthly and records added as new information are published.

LactMed is part of NLM's Toxicology Data Network (TOXNET) suite of toxicology-related databases, and it can be searched with those databases to obtain additional relevant drug information.

James E Knoben, Pharm.D., M.P.H.