Skip to Content

Natalizumab use while Breastfeeding

Drugs containing Natalizumab: Tysabri

Natalizumab Levels and Effects while Breastfeeding

Summary of Use during Lactation

One case indicates that natalizumab is excreted into breastmilk in increasing amounts over several weeks after initiation of therapy. The actual time of the peak level is unknown, but might be as long as 6 months. Because natalizumab is a large protein molecule with a molecular weight of about 149,000, absorption is unlikely because it is probably destroyed in the infant's gastrointestinal tract. Some, but not all, experts recommend avoiding breastfeeding with natalizumab.[1][2][3][4] Until more data become available, natalizumab should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant.

Drug Levels

Maternal Levels. A woman was started on natalizumab 300 mg intravenously while nursing her 11.5 month old infant. Multiple milk levels were obtained almost daily over the 50 days after she received a dose on day 1 and another on day 29. Natalizumab was undetectable (<250 mcg/L) in breastmilk until day 14 when a concentration of 333 mcg/L was measured. A peak level of 1.01 mg/L was detected on day 20. On day 29, the natalizumab milk level was 491 mcg/L when the second dose was given. Milk levels increased to a maximum of 2.83 mg/L on day 50 when breastmilk collection ceased. The authors estimated that a fully breastfed infant would receive a weight-adjusted dosage of 1.7% using the average level over the 50 days and 5.3% using the peak milk level. However, in this study, steady-state was probably not achieved, so the amounts in breastmilk could continue to increase over a period of about 6 months.[5]

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

(Inflammatory Bowel Disease) Budesonide, Infliximab, Mesalamine, Prednisone, (Multiple Sclerosis) Glatiramer Acetate, Interferon beta

References

1. Yarur A, Kane SV. Update on pregnancy and breastfeeding in the era of biologics. Dig Liver Dis. 2013;45:787-94. PMID: 23474350

2. Ghezzi A, Annovazzi P, Portaccio E et al. Current recommendations for multiple sclerosis treatment in pregnancy and puerperium. Expert Rev Clin Immunol. 2013;9:683-91. PMID: 23899239

3. Hassid B, Mahadevan U. The use of biologic therapy in pregnancy: a gastroenterologist's perspective. Curr Opin Rheumatol. 2014;26:347-53. PMID: 24625373

4. 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. PMID: 25415167

5. Baker TE, Cooper SD, Kessler L, Hale TW. Transfer of natalizumab into breast milk in a mother with multiple sclerosis. J Hum Lact. 2015;31:233-6. DOI: doi:10.1177/0890334414566237

Natalizumab Identification

Substance Name

Natalizumab

CAS Registry Number

189261-10-7

Drug Class

Antibodies, Monoclonal

Anti-Inflammatory Agents

Administrative Information

LactMed Record Number

716

Last Revision Date

20150602

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.

Disclaimer: This information is not intended as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. Use of this website signifies your agreement to the Terms of Use and Online Privacy Policy.

Hide