Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2009 Aug;55(8):797-8.

Pharmacologic treatment of hyperthyroidism during lactation

Miguel Marcelo Glatstein, Facundo Garcia-Bournissen, Norberto Giglio, Yaron Finkelstein, Gideon Koren

Pharmacologic treatment of hyperthyroidism during lactation

Miguel Marcelo Glatstein et al. Can Fam Physician. 2009 Aug.

Abstract
in English, French

Question: I have a patient who has hyperthyroidism due to Graves disease. She was taking methimazole but discontinued when she found out she was pregnant. She is currently close to delivery and might require antithyroid therapy in the postpartum period. Can methimazole cross into human milk, and is breastfeeding safe for her infant?

Answer: The exposure of infants to methimazole or propylthiouracil through breast milk is minimal and not clinically significant. Women with hyperthyroidism using methimazole or propylthiouracil should not be discouraged from breastfeeding, as the benefits of breastfeeding largely outweigh the theoretical minimal risks.

QUESTION Une de mes patientes fait de l’hyperthyroïdie à cause de la maladie de Graves. Elle prenait du méthimazole, mais a cessé quand elle a appris qu’elle était enceinte. Elle accouchera bientôt et pourrait avoir besoin d’une thérapie antithyroïdienne après la naissance. Le méthimazole est-il transmis dans le lait maternel, et l’allaitement est-il sans danger pour le nourrisson?

RÉPONSE L’exposition des nourrissons au méthimazole ou au propylthiouracil dans le lait maternel est minimale et peu significative sur le plan clinique. Il ne faut pas décourager les femmes atteintes d’hyperthyroïdie qui prennent du méthimazole ou du propylthiouracil d’allaiter puisque les bienfaits de l’allaitement dépassent largement les risques théoriques minimaux.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

References

    1. Humar M, Dohrmann H, Stein P, Andriopoulos N, Goebel U, Roesslein M, et al. Thionamides inhibit the transcription factor nuclear factor-kappaB by suppression of Rac1 and inhibitor of kappaB kinase alpha. J Pharmacol Exp Ther. 2008;324(3):1037–44. Epub 2007 Nov 30. - PubMed
    1. Davidson B, Soodak M, Neary JT, Strout HV, Kieffer JD, Mover H, et al. The irreversible inactivation of thyroid peroxidase by methylmercaptoimidazole, thiouracil, and propylthiouracil in vitro and its relationship to in vivo findings. Endocrinology. 1978;103(3):871–82. - PubMed
    1. Van Doorn J, Roelfsema F, van der Heide D. The effect of propylthiouracil and methimazole on the peripheral conversion of thyroxine to 3,5,3’-triiodothyronine in athyreotic thyroxine-maintained rats. Acta Endocrinol (Copenh) 1983;103(4):509–20. - PubMed
    1. Beck-Peccoz P, Persani L, LaFranchi S. Safety of medications and hormones used in the treatment of pediatric thyroid disorders. Pediatr Endocrinol Rev. 2004;2(Suppl 1):124–33. - PubMed
    1. Streetman DD, Khanderia U. Diagnosis and treatment of Graves disease. Ann Pharmacother. 2003;37(7–8):1100–9. - PubMed

Publication types

MeSH terms