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Alemtuzumab use while Breastfeeding

Medically reviewed by Last updated on Jun 5, 2023.

Drugs containing Alemtuzumab: Lemtrada, Campath

Alemtuzumab Levels and Effects while Breastfeeding

Summary of Use during Lactation

No information is available on the clinical use of alemtuzumab during breastfeeding. Because alemtuzumab is a large protein molecule with a molecular weight of 145,454 Da, the amount in milk is likely to be very low.[1] It is also likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal.[2] Until more data become available, alemtuzumab should be used with caution or avoided in nursing mothers during treatment for multiple sclerosis, especially while nursing a newborn or preterm infant.[3-7] Waiting for at least 2 weeks postpartum to resume therapy may minimize transfer to the infant.[7] The manufacturer recommends that women not breastfeed during treatment and for at least 3 months following the last dose.

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

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.

Alternate Drugs to Consider

(Multiple Sclerosis) Glatiramer, Immune Globulin, Interferon Beta


Stratigakis A, Paty D, Zou P, et al. A regression approach for assessing large molecular drug concentration in breast milk. Reprod Breed 2023;3:199-207. doi:10.1016/j.repbre.2023.10.003 [CrossRef]
Anderson PO. Monoclonal antibodies during breastfeeding. Breastfeed Med 2021;16:591-3. [PubMed: 33956488]
Bove R, Alwan S, Friedman JM, et al. Management of multiple sclerosis during pregnancy and the reproductive years: A systematic review. Obstet Gynecol 2014;124:1157-68. [PubMed: 25415167]
Cree BA. Update on reproductive safety of current and emerging disease-modifying therapies for multiple sclerosis. Mult Scler 2013;19:835-43. [PubMed: 23319073]
Almas S, Vance J, Baker T, Hale T. Management of multiple sclerosis in the breastfeeding mother. Mult Scler Int 2016;2016:6527458. [PMC free article: PMC4757692] [PubMed: 26966579]
Iyer P, Dobson R. Multiple sclerosis in pregnancy: A commentary on disease modification and symptomatic drug therapies. Neurol Ther 2023;12:1-10. [PMC free article: PMC9837363] [PubMed: 36443593]
Krysko KM, Dobson R, Alroughani R, et al. Family planning considerations in people with multiple sclerosis. Lancet Neurol 2023;22:350-66. [PubMed: 36931808]

Substance Identification

Substance Name


CAS Registry Number


Drug Class

Breast Feeding


Milk, Human

Antineoplastic Agents

Antibodies, Monoclonal, Humanized

Immunosuppressive Agents

Disclaimer: 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.

Further information

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