Is 5FU Safe in Breastfeeding

I am a breastfeeding mother and i want to know if it is safe to use 5FU? Is 5FU safe for nursing mother and child? Does 5FU extracts into breast milk? Does 5FU has any long term or short term side effects on infants? Can 5FU influence milk supply or can 5FU decrease milk supply in lactating mothers?

Drug is cleared from the body in 28 elimination half-lives. Resuming breastfeeding is likely safe after 24 hours of pumping-and-dumping.

Most sources consider breastfeeding to be contraindicated during maternal antineoplastic drug therapy. It might be possible to breastfeed safely during intermittent therapy with an appropriate period of breastfeeding abstinence, but the duration of abstinence is not clear. Limited information indicates that a maternal continuous intravenous 5FU infusion at a dose of 200 mg/square meter daily produces undetectable levels in milk. If 5FU use is undertaken, monitoring of the infant's complete blood count and differential is advisable. Chemotherapy may adversely affect the normal microbiome and chemical makeup of breastmilk.[1] Women who receive chemotherapy during pregnancy are more likely to have difficulty nursing their infant. Topical 5FU applied away from the breast should pose negligible risk for the breastfed infant; however, it is important to ensure that the infant's skin does not come into direct contact with the areas of skin that have been treated.

A telephone follow-up study was conducted on 74 women who received cancer chemotherapy at one center during the second or third trimester of pregnancy to determine if they were successful at breastfeeding postpartum. Only 34% of the women were able to exclusively breastfeed their infants, and 66% of the women reported experiencing breastfeeding difficulties. This was in comparison to a 91% breastfeeding success rate in 22 other mothers diagnosed during pregnancy, but not treated with chemotherapy. Other statistically significant correlations included: 1. mothers with breastfeeding difficulties had an average of 5.5 cycles of chemotherapy compared with 3.8 cycles among mothers who had no difficulties; and 2. mothers with breastfeeding difficulties received their first cycle of chemotherapy on average 3.4 weeks earlier in pregnancy. Of the 9 women who received a 5FU-containing regimen, 8 had breastfeeding difficulties.[3]