Last update March 31, 2023
Very Low Risk
Thiopurine an imidazole derivative and prodrug of 6-mercaptopurine (6-MP) that is rapidly metabolized in vivo to 6-MP and 6-thioguanine nucleosides (6-TGNs). It has immunosuppressive properties and is used in organ transplantation, autoimmune diseases such as rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, dermatomyositis, polymyositis, autoimmune chronic active hepatitis, pemphigus vulgaris, polyarteritis nodosa, autoimmune hemolytic anemia, idiopathic thrombocytopenic purpura, and pyoderma gangrenosum , among others (AEMPS 2016, Sanis HI 2015). Prescribed orally or intravenously in regimes of two or three daily doses for months to years or indefinitely.
Azathioprine or its metabolites 6-MP and 6-TGN are not excreted, or are excreted in clinically insignificant amounts, through breastmilk.(Christensen 2008, Sau 2007, Moretti 2006, Kane 2004, Coulam 1982)
Infections or other type of problems have not been reported in infants that consume breastmilk from women that take it during short or long terms. (Ikram 2021, Boyle 2021, Klintmalm 2020, de Meij 2013, Bernard 2013, Mahadevan 2012, Angelberger 2011, Christensen 2009, Zelinkova 2009, Sau 2007, Werner 2007, Gardiner 2007 y 2006, Moretti 2006, Muñoz 2001, Nyberg 1998, Grekas 1984, Coulam 1982)
Plasma 6-MP levels of these infants were very low or undetectable (Zelinkova 2009, Sau 2007, Bernard 2007, Gardiner 2007 and 2006). IgA levels in breast milk were normal. (Coulam 1982)
There have been few cases of asymptomatic mild neutropenia in infants (Sau 2007, Bernard 2013), therefore some authors consider it convenient to carry out analytical controls (Almas 2016). Exposure is further minimized if one can wait 4 hours to breastfeed after the last dose (McConnell 2016, Bar-Gil 2016, Mahadevan 2015, Butler 2014), as the peak of 6-MP in milk occurs in the first 4 hours , dropping to 10% at the 6th hour. (Christensen 2008)
Cases of hyperprolactemia and/or galactorrhea have been described. (Chaudhary 2021, Uygur 2003)
The majority of medical societies, experts and expert consensus consider the use of this medication safe during lactation.(Russell 2022, Sammaritano 2020 and 2014, Mahadevan 2019 and 2015, Vestergaard 2019, Bermejo 2018, BitenCourt 2018, Gilhus 2018, Anderson 2016, Noviani 2016, Nguyen 2016, McConnell 2016, Bar-Gil 2016, Souls 2016, Huang 2016, Mottet 2016, Flint 2016, Gotestam 2016, Van Der Woude 2015, Briggs 2015, Schaefer 2015, DURST 2015, Nielsen 2014, Constantinesc 2014, Schulze 2014, Butler 2014, Huang 2014, Yarur 2013, Habal 2012, Selinger 2012, Makol 2011, Gisbert 2010, Raj 2010, Van Aseche 2010, van der Woude 2010, Zelinkova 2009, Christensen 2009 and 2008, Mottet 2007, Gardiner 2007 and 2006, Moretti 2000)
We do not have alternatives for Azathioprine since it is relatively safe.
Suggestions made at e-lactancia are done by APILAM team of health professionals, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it. The pharmaceutical industry contraindicates breastfeeding, mistakenly and without scientific reasons, in most of the drug data sheets.
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Thank you for helping to protect and promote breastfeeding.
e-lactancia is a resource recommended by Academy of Breastfeeding Medicine - 2012 of United States of America
Would you like to recommend the use of e-lactancia? Write to us at corporate mail of APILAM