Last update April 13, 2020
Very Low Risk
An antineoplastic antimetabolite and immunosuppressant. It interferes with the synthesis of nucleic acid by inhibiting the metabolism of purines.
Used in the treatment of leukemias and inflammatory bowel disease. It is the active metabolite of azathioprine, which is converted in the body into mercaptopurine.
Very low (Christensen 2008, Sau 2007, Moretti 2006, Coulam 1982) or undetectable (Ter Horst 2020, Kane 2004) levels have been measured in breast milk.
It has not been found in the serum of infants whose mothers were treated with azathioprine (Zelinkova 2009, Sau 2007, Gardiner 2006) and these infants did not show any infectious or other problems (Angelberger 2011, Zelinkova 2009, Sau 2007, Moretti 2006, Grekas 1984, Coulam 1982), including three premature infants (Sau 2007).
Experts and scientific associations consider the use of mercaptopurine or azathioprine during breastfeeding to be low-risk (Noviani 2016, Nguyen 2016, Mottet 2016, van der Woude 2015 and 2010, Huang 2014, Nielsen 2014, Yarur 2013, de Meij 2013, Habal 2012, Selinger 2012, Van Assche 2010, Gisbert 2010, Raj 2010, Christensen 2008, Mottet 2007).
Given the strong evidence that exists on the benefits of breastfeeding for the development of babies and the health of mothers, it is advisable to evaluate the risk-benefit of any maternal treatment, including chemotherapy, individually advising each mother that wishes to continue with breastfeeding (Koren 2013).
We do not have alternatives for 6-Thioxopurine 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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