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Busulfan use while Breastfeeding

Drugs containing Busulfan: Myleran, Busulfex

Medically reviewed by Last updated on Jan 29, 2019.

Busulfan Levels and Effects while Breastfeeding

Summary of Use during Lactation

Most sources consider breastfeeding to be contraindicated during maternal antineoplastic drug therapy.[1] It might be possible to breastfeed safely during intermittent therapy with an appropriate period of breastfeeding abstinence. Although minimal data are available to determine an appropriate period to withhold breastfeeding, the drug's terminal half-live of 2.5 hours suggests that withholding breastfeeding for at least 24 hours may be sufficient. 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.[3]

Drug Levels

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

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

Effects in Breastfed Infants

Busulfan in a dosage of 4 mg/day for 5 weeks was taken for myeloid leukemia by one woman while breastfeeding. Weekly monitoring found no adverse effects on her infant's leukocyte count or hemoglobin.[3]

Effects on Lactation and Breastmilk

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


1. Pistilli B, Bellettini G, Giovannetti E et al. Chemotherapy, targeted agents, antiemetics and growth-factors in human milk: How should we counsel cancer patients about breastfeeding? Cancer Treat Rev. 2013;39:207-11. PMID: 23199900

2. Urbaniak C, McMillan A, Angelini M et al. Effect of chemotherapy on the microbiota and metabolome of human milk, a case report. Microbiome. 2014;2:24. PMID: 25061513

3. Stopenski S, Aslam A, Zhang X et al. After chemotherapy treatment for maternal cancer during pregnancy, is breastfeeding possible? Breastfeed Med. 2017;12:91-7. PMID: 28170295

4. Bounameaux Y, Durenne JM. [A case of leukemia in a lactating female: effect of treatment with busulfan on the infant]. Ann Soc Belge Med Trop. 1964;44:381-3. PMID: 14259241

Busulfan Identification

Substance Name


CAS Registry Number


Drug Class

Breast Feeding


Antineoplastic Agents

Alkylating Agents

Administrative Information

LactMed Record Number



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Further information

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