Detection of lithium in breast milk and the mammary glands

摘要

Lithium is a key component in many anti-psychosis medications and can be transmitted to the breast-fed infantsof medicated mothers. Using laser induced breakdown spectroscopy (LIBS), trace lithium levels are observed inthe breast milk of lactating rats administered with lithium postpartum with limit of detection of LIBS about 0.1ppm. Subsequently, the mammary glands of female rats were analyzed using LIBS and inductively coupledplasma mass spectrometry. Lithium at 1.06 μg/g concentration was measured in the mammary glands of lithiummedicated subjects, but was below the limit of detection in controls. Lithium also increases iodine content(p<0.05), decreases phosphorus content, and increases the calcium/phosphorus ratio in the glands (p<0.05).Lithium is present in the breast milk and mammary glands of medicated female subjects and this is the likelyroute of entry to breast-fed infants. Lithium use in pre-partum has been associated with a number of negativeeffects in the newborn. These effects are conventionally resolved by reducing the pre-partum dose. However,current practice guidelines in post-partum discourage use of lithium during breast-feeding due to transientabnormalities of thyroid-stimulating hormone and blood urea nitrogen. This however, denies the infant themany benefits of breast feeding, or requires the mother to stop or change medications. The most recentguideline is still cautious as there is little evidence beyond a handful of case reports. Therefore, there issignificant need for further research. This study helps establish the rat as an animal model for studying thebiodistribution of lithium.