Is Etoposide safe while breastfeeding?

Summary of use during breastfeeding

Most sources consider breastfeeding to be contraindicated during maternal antineoplastic drug therapy. It might be possible to breastfeed safely during intermittent therapy with etoposide or etopophos after an appropriate period of breastfeeding abstinence. A period of at least 24 hours is required after a dose of 80 mg/sq. m. or less. Others have suggested an abstinence period of 72 hours after etoposide use.[1] Chemotherapy may adversely affect the normal microbiome and chemical makeup of breastmilk.[2] Women who receive chemotherapy during pregnancy are more likely to have difficulty nursing their infant.

Effects on the breastfed infant

One mother received with 5 daily doses of etoposide 80 mg/sq. m. and cytarabine 170 mg/sq. m. intravenously as well as 3 daily doses of 6 mg/sq. m. of mitoxantrone intravenously. She resumed breastfeeding her infant 3 weeks after the third dose of mitoxantrone at a time when mitoxantrone was still detectable in milk. The infant had no apparent abnormalities at 16 months of age.[3]

Effects on milk supply

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 taxane-containing regimen, 7 had breastfeeding difficulties.[4]

Levels in milk

Maternal Levels. A woman treated with etoposide, mitoxantrone and cytarabine for promyelocytic leukemia received 5 daily etoposide doses of 80 mg/sq. m. intravenously. Etoposide milk levels reached peaks of about 600, 580 and 800 mcg/L immediately after the last 3 doses, respectively. Etoposide was undetectable (assay limit not specified) in milk 24 hours after each dose.[3]

Infant Levels. Relevant published information was not found as of the revision date.