Is it safe to nurse a baby while taking Rituxan?

Here is My Question:
I'm newly diagnosed (last September) 2 months post delivery of my third child and I just had my first Rituxan infusion yesterday. I chose this medication because I want to nurse. I'm reading conflicting theories about its ability to cross into breast milk. My doctor told it it's too large to pass but other websites I've been reading say that it does pass. Can you clarify if it is safe to nurse on this medication and if so how long do I need to wait after infusion (pump and dump for how many days)?

Answer:
There is no data specific to Rituximab and breastfeeding. It has been found in breast milk in some animal studies but because rituximab is a large protein molecule, the amount in milk is likely to be very low. When we look at other monoclonal antibodies that have limited data, there has not been ill effects for infants who are breastfeeding. Some experts say that if this drug is required by the mother, it is not a reason to discontinue breastfeeding. The half life of rituximab in a mother would be about 6 weeks, with the highest concentrations in the first 2 weeks. In general we think nursing is safe, but there is limited data and we tend to defer to a person's treating physician.


Benjamin M. Greenberg, MD, MHS, FAAN, FANA, CRND 
Vice Chair Translational Research and Ambulatory Affairs
Department of Neurology and Neurotherapeutics
Director, Transverse Myelitis and Neuromyelitis Optica Program
Co-Director, Pediatric CONQUER Program
Department of Pediatrics
UT Southwestern