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This Forum has been the centre of an exceptional exchange of knowledge diagnosis, treatment, symptoms and other effects of cancer during pregnancy and lactation. All are welcome to review the Questions and Answers posted here, provided that they acknowledge and accept the important proviso and disclaimer below.
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Forum > Cancer - Active Topics: Cancer - Active Topics
Methotrexate and breastfeeding

Date: 2009-06-22

Ectopic pregnancies are treated with Methotrexate 50 mg/m2 IM. We have a case where the patient who received this dose was breastfeeding an infant. How long should a patient wait before being allowed to resume breastfeeding after this single dose of IM Methotrexate?

The half life for Methotrexate is 8-15 hours. For breastfeeding, the general advice is that if less than 10% of the maternal weight adjusted dose passes into the milk, the medication is considered compatible for breastfeeding. With Methotrexate the relative infant dose indicated is 0.12% of the maternal dose, which is extremely negligible. However Methotrexate can be retained in human tissue particularly neonatal GI tissue and ovarian cells for months. With chronic exposure therefore the potential for hazard for the infant may increase as the dose accumulates in his/her body. It is advisable for the milk to be pumped and discarded for a minimum of four days before resuming breastfeeding.

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