Evidence mapPaperPMID 12545145Full record

Trial reportClinical pharmacology and therapeutics2003

Transfer of metformin into human milk.

Sharon J Gardiner, Carl M J Kirkpatrick, Evan J Begg, Mei Zhang, M Peter Moore, Dorothy J Saville

Registry-linked trialAbstract readClinical Trial
PubMed Publisher
In one paragraph

Trial report in Clinical pharmacology and therapeutics, 2003. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06948825 (Effectiveness Study of a Lifestyle Intervention Versus Metformin in Mothers With Recent Gestational Diabetes), which is not on this map. Cited by 23 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
23citing papers in PubMed, 1 pooled it
4.0field-weighted citation impact, top 6% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT06948825 phase2recruitingstarted 2025, after this paper: background citation

Effectiveness Study of a Lifestyle Intervention Versus Metformin in Mothers With Recent Gestational Diabetes

Ran2025Enrolled60Registered outcomes12Posted comparisons0ConditionsGestational Diabetes Mellitus in Pregnancy, Postpartum Care, Weight LossArmsEnhanced Lifestyle Intervention, Lifestyle Intervention, Metformin Hcl 850Mg Tab
Open the trial in the graph
3 · Its place in the literature

Who cites it

23 citing papers in PubMed, 1 synthesis or guideline pooled it, 91 citations in OpenAlex.

  1. Pooled it
  2. Article
  3. Article
  4. Review
  5. Review
  6. Article
  7. Article
  8. Review
  9. Review
  10. Article
  11. Review
  12. Use of oral anti-diabetic agents in pregnancy: a pragmatic approach.North American journal of medical sciences · 2015
    Review
  13. Review
  14. Peripartum management of diabetes.Indian journal of endocrinology and metabolism · 2013
    Review
  15. Oral Hypoglycemic Agents in pregnancy: An Update.Journal of obstetrics and gynaecology of India · 2013
    Review
  16. Gestational diabetes mellitus: Non-insulin management.Indian journal of endocrinology and metabolism · 2011
    Article
  17. Clinical pharmacokinetics of metformin.Clinical pharmacokinetics · 2011 · on this map
    Review
  18. Pharmacokinetics of metformin during pregnancy.Drug metabolism and disposition: the biological fate of chemicals · 2010
    Article
  19. Article
  20. Use of hypoglycemic drugs during lactation.Canadian family physician Medecin de famille canadien · 2009
    Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors at 2 institutions in 1 country.

Sharon J GardinerDepartment of Clinical Pharmacology and Diabetes Centre, Christchurch Hospital, Christchurch, New Zealand. sharon.gardiner@cdhb.govt.nz
Carl M J Kirkpatrick
Evan J Begg
Mei Zhang
M Peter Moore
Dorothy J Saville
Christchurch Hospital · NZUniversity of Otago · NZ

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

objectivesOur objectives were to determine the milk-to-plasma ratio of metformin in lactating mothers and to estimate infant exposure.

methodsTwo 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.

resultsIn 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 concentration-time curve analysis were 0.27 and 0.47 and the infant doses were 0.11% and 0.25%. The concentration-time profile for metformin in milk in all subjects was unexpectedly flat.

conclusionsMetformin appears to be "safe" during lactation because of low infant exposure. The unusual concentration-time profile for metformin in milk suggests that the transfer of metformin into milk is not solely dependent on passive diffusion.

Indexed as

AdultArea Under CurveChromatography, High Pressure LiquidFemaleHumansHypoglycemic AgentsLactationMetforminMilk, HumanTime FactorsHypoglycemic AgentsMetformin

Identifiers

PMID12545145
OpenAlexW2058824697

What Socratic holds

Textmetadata
Read underepoch 390

Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the Socratic graph.