ABSTRACT
Human milk is a significant route of drug excretion from the maternal system and of infant drug exposure during lactation which has frequently been ignored in the past. A review of the literature reveals a scarcity of information on this topic, and many conclusions based on single case reports. With the development of the science of pharmacokinetics, studies of drug excretion into human milk may be designed in accord with the properties of the specific drug in question. Without consideration of both drug pharmacokinetics and variability patterns of human milk composition, as lactation advances, within a single day, and even within a single nursing, results of studies of drug excretion into human milk may be misleading and offer little information from which recommendations to the lactating mother may be made. This review will focus on available literature to date concerning drugs excreted in human milk, and on some of the potential and observed effects of infant exposures to these drugs, in an attempt to highlight the dearth of information concerning this portal of drugs to the infant.
