Propylthiouracil (PTU)

Anti-thyroid drug that blocks the production of thyroid hormones. Indicated in hyperthyroidism. Oral administration in one to two daily doses.

Small amount of Propylthiouracil can reach the breast milk and it doesn't cause harm to the thyroid function.^{(Low 1979, Kampmann 1980, Cooper 1987)}

Several medical societies, experts and expert consensus, consider the use of this medication to be safe during breastfeeding. ^{(Hale, LactMed, Peng 2022, Dumitrascu 2021, Amino 2020, Alexander 2017, Stagnaro 2011, Inoue 2009, Glatstein 2009, Marx 2008, Azizi 2006, Bartalena 2005, Mandel 2001, Momotani 2000 & 1989, Cooper 1987, McDougall 1986, Kampmann 1980 )}

The American Thyroid Association and other authors ^{(Amino 2020, Alexander 2017, Stagnaro 2011, Mandel 2001)} stated that a daily dose as high as 450 mg is safe while breastfeeding. However, some studies have shown no harmful effect at a daily dose as high as 750 mg ^{(Inoue 2009, Glatstein 2009, Marx 2008, Azizi 2006, Bartalena 2005, Momotani 2000 y 1989, Cooper 1987, McDougall 1986, Kampmann 1980)}. Some author recommend a maximum of 300 mg daily during breastfeeding. ^{(Dumitrascu 2021)}

Routine laboratory monitoring of thyroid function is not recommended in healthy infants who are developing well clinically. ^{(Alexander 2017)}

Methimazole or Carbimazole is preferred since liver toxicity has been found among patients who were treated with Propylthiouracil. ^{(Karras 2009, 2010 y 2012, Azizi 2011, Serrano 2014, Hudzik 2016)}

No se precisa 

The American Academy of Pediatrics has rated it as compatible with breastfeeding. ^{(AAP 2001)}

Eleventh WHO Model List of Essential Drugs 2002: Compatible with breastfeeding. ^{(OMS 2002)}