Is Interferon Beta safe while breastfeeding?

Effects on the breastfed infant

Six women had been receiving interferon beta-1a (Avonex, Biogen) 30 mcg intramuscularly once weekly for multiple sclerosis for months to years. None of the mothers noticed any adverse effects in their breastfed infants.[ 7 ] A woman received interferon beta-1b (Betaferon, BayerHealthCare; dosage unspecified) for multiple sclerosis throughout pregnancy. She continued the drug while she exclusively breastfed her infant. At 5 months of age, the infant was monitored regularly by a physician and was developing well with no abnormalities.[ 8 ] One mother received interferon beta-1a for multiple sclerosis during pregnancy and postpartum. All of their infants were exclusively breastfed for 6 months and no noticeable problems were reported in any of them.[ 9 ] In data collected from 4 countries, 17 women received interferon, and 41 women received glatiramer during pregnancy and postpartum for treatment of multiple sclerosis. Of these, 63% breastfed (extent not stated) their infants for a mean of 8.8 months. No mention was made of adverse reactions in breastfed infants.[ 10 ] Thirty-nine women with multiple sclerosis who were treated with interferon beta-1a during breastfeeding were followed by the German Multiple Sclerosis and Pregnancy Registry. During breastfeeding, the drug was administered every other day (n = 8), 3 times a week (n = 15), or once a week (n = 12). In addition, one woman receive peginterferon beta-1a every 2 weeks, and in 3 additional women, the frequency was not known. One woman received both interferon beta-1a every other day and glatiramer daily. Most infants were also exposed during pregnancy. Infants were breastfed for an average of 9.2 months (range 1.6 to 28.5 months) during interferon therapy. Infants were followed for 1 year and most developed normally; the percentages of infants with developmental delay, courses of antibiotics and hospitalizations did not differ from the reference German population. No conditions attributable to interferon beta-1

Effects on milk supply

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

Levels in milk

Maternal Levels . Six women were receiving interferon beta-1a (Avonex, Biogen) 30 mcg intramuscularly once weekly for multiple sclerosis. Milk samples from both breasts were collected after pumping with an electric breast pump 8 times after a dose at baseline and 7 other times during the first 72 hours after a dose. Samples were combined and analyzed for interferon beta-1a. About half of the samples had undetectable ( 20 ng/L) amounts of drug. The highest concentrations were found at 1 or 4 hours after the dose in all women. The highest concentration found was 171 ng/L in one woman. Using this value, the authors estimated that the maximum weight-adjusted dosage that an infant would receive is 0.006% of the maternal dose.[ 7 ] Infant Levels . Relevant published information was not found as of the revision date.

Alternatives LactMed lists

• Interferon Alfacon-1
• Immune Globulin