Transfer of metformin into human milk
Abstract
OBJECTIVES: Our objectives were to determine the milk-to-plasma ratio of metformin in lactating mothers and to estimate infant exposure.
METHODS: Two studies were performed. In study 1, 3 nursing mothers taking metformin were studied throughout a dosing interval at steady state. Blood samples were obtained from 2 suckling infants. In study 2, 5 healthy lactating women who volunteered to express milk after weaning were given metformin, 500 mg, at weaning and were studied for up to 72 hours. In both studies, areas under the plasma and milk concentration-time curves were estimated, and the milk-to-plasma concentration ratio based on area under the concentration-time curve analysis was derived. The infant dose was calculated by standard methods.
RESULTS: In study 1 the milk-to-plasma concentration ratios based on area under the concentration-time curve analysis were 0.37, 0.50, and 0.71. The estimated "doses" of metformin that would be ingested by the breast-fed infants were 0.18%, 0.20%, and 0.21% of the maternal doses, adjusted for weight. In the breast-fed infants, no metformin was detected (n = 2) or adverse effects noted (n = 3). In study 2, the milk-to-plasma concentration ratio based on area under the concentration-time curve analysis was unable to be calculated for 3 subjects because of the unexpected persistence of metformin in milk beyond the study period. For the 2 subjects studied for 72 hours, the milk-to-plasma concentration ratios based on area under the…
How strong is the evidence?
Evidence Hub reads this as a clinical trial, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence.
Read the paper
Related studies
- Metformin as an adjuvant in breast cancer treatment
- Metformin Lysosomal Targeting: A Novel Aspect to Be Investigated for Metformin Repurposing in Neurodegenerative Diseases?
- Aberrant HSF1 signaling activation underlies metformin amelioration of myocardial infarction in mice
- Metformin induces ZFP36 by mTORC1 inhibition in cervical cancer-derived cell lines
- Protein Interaction Network for Identifying Vascular Response of Metformin (Oral Antidiabetic)
- Preventing Long COVID With Metformin
Go deeper in Evidence Hub
Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.