How medicines you take show up in breast milk and how much your baby might get
Medication Concentrations in Human Milk (MedMilk) and Potential Adverse Effects in Breastfed Infants: an Exploratory Clinical Study
See how medicines taken by breastfeeding women show up in breast milk and how much their babies might be exposed to.
Quick facts
| Study type | Observational |
|---|---|
| Enrollment | 250 (estimated) |
| Ages | 18 Years and up |
| Sex | Female |
| Sponsor | University Hospital Bispebjerg and Frederiksberg Academic / other |
| Locations | 3 sites (Copenhagen and 2 other locations) |
| Trial ID | NCT07346716 on ClinicalTrials.gov |
What this trial studies
This prospective observational study enrolls breastfeeding women who are already taking prescription or over-the-counter medicines as part of routine care. Participants provide timed small breast milk samples, one urine sample, and answer questions about maternal and infant health and breastfeeding patterns. Samples are stored and later analyzed using UPLC-MS/MS to measure drug concentrations and calculate relative infant doses where data are sufficient. No experimental drugs are given and results will be reported descriptively to add to knowledge about medication transfer into human milk.
Who should consider this trial
Good fit: Breastfeeding women aged 18 or older who are currently taking one or more prescription or over-the-counter medicines and can provide informed consent and milk/urine samples are ideal candidates.
Not a fit: Pregnant women, people who are not breastfeeding, or those with known significant drug-drug interactions at the time of sampling are excluded and would not benefit from participating.
Why it matters
Potential benefit: If successful, the results could lead to safer prescribing and clearer counseling for breastfeeding mothers by providing data on how much medicine reaches an infant through milk.
How similar studies have performed: Previous small pharmacokinetic and case studies have measured drug levels in breast milk, but systematic prospective multi-drug data remain limited.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: * Lactating women aged ≥18 years * Current use of one or more prescription or over-the-counter (classified within the ATC system) drugs * Able and willing to provide written informed consent Exclusion Criteria: * Current pregnancy during sample collection * Known and clinically significant pharmacokinetic drug-drug interactions at the time of sampling
Where this trial is running
Copenhagen and 2 other locations
- Department of Clinical Pharmacology — Copenhagen, Denmark (Recruiting)
- Mental health services, Capital Region of Denmark — Copenhagen, Denmark (Recruiting)
- Department of Obstetrics and Gynecology, Herlev Hospital — Herlev, Denmark (Recruiting)
Study contacts
- Principal investigator: Jon Traerup Andersen, Professor, MD, PhD — Department of Clinical Pharmacology, Bispbjeg and Frederiksberg Hospital
- Study coordinator: Ditte Resendal Gotfredsen, MD
- Email: ditte.resendal.gotfredsen@regionh.dk
- Phone: +4521472051
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.