Seasonal allergies, diabetes and post-partum depression affect breastfeeding women worldwide. But there is very little information available about the transfer of drugs to breast milk and infants. Women who are breastfeeding are rarely included in clinical trials, but they still deserve to know if their medicines are safe. ConcePTION researchers recently published a paper in the Journal of Chromatography B that describes two developed and validated methods to determine how much of a drug the mother takes also transfers to her breastmilk, and potentially to her infant.
“We have established a method for quantifying the transfer of cetirizine, a drug commonly used by breastfeeding women for allergic conditions, in breastmilk, and venlafaxine and its active metabolite o‑desmethylvenlafaxine, a common antidepressant drug used during breastfeeding,” says Christine Wegler, who were part of a team of researchers from the Uppsala Drug Optimization and Pharmaceutical Profiling (UDOPP), Uppsala University, responsible for the analysis.
The authors also developed a method for quantification of the blood sugar-lowering agent metformin, used for the treatment of preexisting type 2 diabetes and gestational diabetes (where a pregnant woman develops the condition) in breastmilk and blood plasma. According to the authors, this enables the measurement of how much metformin is present in the infant’s bloodstream. And as a result, the determination of how metformin transfers to breastmilk.
The methods are made for high-throughput analysis, which enables the analysis of dozens, hundreds or even several hundreds of samples per day, with simple sample preparation for minimal loss of drug compounds, and rapid analysis. In total, it takes less than 3 minutes per sample. The minimal sample volume needed is 40 µL (microliters).
“This means, for example, that very small volumes of blood are required to determine the metformin level in the infant’s bloodstream. The methods are also highly sensitive and can measure at least 100 times lower levels than what have been possible with previous methods in the bloodstream after drug use. We are talking concentrations down to 0.65 µg/L [micrograms per litre],” Christine Wegler concludes.
With more knowledge, women can make informed decisions about whether or not to treat their health conditions. According to the authors, their work is contributing to the knowledge base on medicine safety in breastfeeding that is so desperately needed.
By Anna Holm
Read the paper: Wegler C, Saleh A, Lindqvist A, Nordeng H, Smeraglia J, Baranczewski B, Simple and rapid quantification of cetirizine, venlafaxine, and O-desmethylvenlafaxine in human breast milk, and metformin in human milk and plasma with UHPLC-MS/MS, Journal of Chromatography B, 2022;1205:123340, https://doi.org/10.1016/j.jchromb.2022.123340.