There are some data about mercaptopurine

The level in milk was studied on 2 women
The first one was taken 75 mg mercaptopurine per day ; maximal level in milk
: 4,5 µg/l
The second was taken 25 mg/day ; maximal level in milk : 18 µg/l

Pediatric dose : 1,5 to 2,5 mg/kg/day

The milk level of IgA was normal. There was strictly no iatrogenic effect
observed in the children. Another study on 2 others women has given same
results.

The doses given to the mothers were not very hight, and the follow up was
not very long. Difficult to know what will happen with higher doses and long
term treatment. It is possible to use mercaptopurine while breastfeeding, if
level in milk and infant's blood are monitored.

Coulam CB et al. Breastfeeding after renal transplantation. Transplant Proc
1982 ; 14 : 605-09.
Grekas DM et al. Immunosuppressive therapy and breastfeeding after renal
transplantation. Nephron 1984 ; 37 : 68.

Hope this helps
Kindly
Françoise Railhet
Manager of the LLLFrance Medical Associates Program
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