THE EXCRETION OF DRUGS IN MILK: A SURVEY

Summary In this review a summary of the literature on the excretion of drugs in milk is reported. Because of the current trend of a return to breast-feeding and the ever-increasing number of drugs available, a thorough understanding of the potential hazard of medication to a nursing mother becomes very important for clinical pharmacists and other health professionals in advising their patients. This review focuses on the physiological and physicochemical factors affecting secretion of different types of drugs into milk. A brief discussion of the mechanisms of drug excretion is also given. Both plasma (or serum) and milk levels of various drugs reported in humans are compiled. Because of the variations in dose regimens, experimental conditions, analytical methods, and subject to subject variations, wide ranges of both plasma and milk levels have been observed for many drugs. More uniform data will be needed to allow meaningful analysis of various physicochemical models proposed to account for the milk/plasma ratio of various drugs in human subjects. Potentially adverse effects of various drugs present in human milk are presented.