Cetirizine is a medicine that is used to prevent and treat allergy symptoms, such as red, itchy eyes, sneezing, a runny or stuffy nose, or hives. This medicine is recommended for breastfeeding women, which makes it important to study how much of the drug transfers to mother’s milk. The ConcePTION project has developed a new pharmacokinetic (popPK) model to predict the concentrations of cetirizine in human breast milk, and to estimate how much of the medicine that is received by the breastfed infant.
The results are published in the journal Basic & Clinical Pharmacology and Toxicology. According to the authors, the concentration of cetirizine in milk was low in relation to the amount of medicine taken by the breastfeeding mother. Which means that the amount of medicine that the breastfeeding baby would ingest is small compared to the mother’s dose. The concentration in milk is also affected by the length of the feeding, or (as in this study) how long it takes to pump or express milk. “Shorter pumping durations lead to higher concentrations, potentially due to changes in milk compositions over time”, says Erik Melander, researcher at the Department of Pharmacy at Uppsala University, and one of the authors of the study.
The results are reassuring for mothers that need to treat their allergies while breastfeeding. According to the authors, the results support the current recommendation that cetirizine is compatible with breastfeeding. “The findings could help improve clinical guidelines and inform product labels, providing clarity for healthcare providers and breastfeeding mothers,” says Erik Melander.
Do you want to know more? Read the article: Melander E, Nielsen EI, Lindqvist A, et al. Population pharmacokinetic modelling of cetirizine concentrations in human breast milk—A contribution from the ConcePTION project. Basic Clin Pharmacol Toxicol. 2024; 1-9. DOI: 10.1111/bcpt.14100