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Fluorouracil use while Breastfeeding

Drugs containing Fluorouracil: Efudex, Carac, Fluoroplex, Tolak, Adrucil, Efudex Occlusion Pack, Fluorac

Fluorouracil Levels and Effects while Breastfeeding

Summary of Use during Lactation

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 fluorouracil infusion at a dose of 200 mg/square meter daily produces undetectable levels in milk. If fluorouracil use is undertaken, monitoring of the infant's complete blood count and differential is advisable. Topical fluorouracil 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.

Drug Levels

Maternal Levels. A mother who was 9 months postpartum was diagnosed with rectal cancer and began treatment with pelvic radiotherapy and a continuous intravenous infusion of fluorouracil 200 mg/square meter daily. Her plasma fluorouracil concentration was constant at about 110 micromoles/L (14.3 mg/L) from weeks 2 to 5 of therapy. She discontinued nursing her infant and pumped her breasts twice daily and collected 36 breastmilk samples before, during and for 10 days following fluorouracil therapy (exact times not specified). Fluorouracil was undetectable (<0.5 micromol/L [<65 mcg/L]) in all of the milk samples.[1]

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

Effects in Breastfed Infants

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

Effects on Lactation and Breastmilk

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

References

Peccatori FA, Giovannetti E, Pistilli B et al. "The only thing I know is that I know nothing": 5-fluorouracil in human milk. Ann Oncol. 2012;23:543-4. PMID: 22275286

Fluorouracil Identification

Substance Name

Fluorouracil

CAS Registry Number

51-21-8

Drug Class

Antimetabolites

Antineoplastic Agents

Antimetabolites, Antineoplastic

Immunosuppressive Agents

Administrative Information

LactMed Record Number

990

Last Revision Date

20160401

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