Cyclophosphamide use while Breastfeeding
Drugs containing Cyclophosphamide: Cytoxan, Neosar, Cytoxan Lyophilized
Cyclophosphamide Levels and Effects while Breastfeeding
Summary of Use during Lactation
Most sources consider breastfeeding to be contraindicated during maternal antineoplastic drug therapy, especially alkylating agents such as cyclophosphamide. Neutropenia has been reported in 2 infants whose mothers breastfed them while receiving cyclophosphamide.
Maternal Levels.Unmetabolized cyclophosphamide was qualitatively detected in milk 1, 3, 5 and 6 hours after IV injection of 500 mg of drug in one patient. Quantitative determination has not been reported.
Infant Levels. Relevant published information was not found as of the revision date.
Effects in Breastfed Infants
In one 23-day-old infant, neutropenia, thrombocytopenia and a low hemoglobin were possibly caused by cyclophosphamide after 3 days of maternal treatment with cyclophosphamide 6 mg/kg IV daily (total dose 300 mg).
In a 4-month-old, neutropenia was probably caused by cyclophosphamide in a mother 9 days after the last of 6 weekly doses of 800 mg cyclophosphamide intravenously, 2 mg vincristine intravenously and daily doses of 30 mg of prednisolone orally. Neutropenia persisted at least 12 days and was accompanied by a brief episode of diarrhea.
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. Duncan JH, Colvin OM, Fenselau C. Mass spectrometric study of the distribution of cyclophosphamide in humans. Toxicol Appl Pharmacol. 1973;24:317-23. PMID: 4741053
3. Wiernik PH, Duncan JH. Cyclophosphamide in human milk. Lancet. 1971;1(7705):912. PMID: 4102054
4. Durodola JI. Administration of cyclophosphamide during late pregnancy and early lactation: a case report. J Nat Med Assoc. 1979;71:165-6. PMID: 423292
5. Amato D, Niblett JS. Neutropenia from cyclophosphamide in breast milk. Med J Aust. 1977;1:383-4. PMID: 859486
CAS Registry Number
LactMed Record Number
Last Revision Date
Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.