Rituximab is a genetically engineered chimeric murine/human monoclonal antibody that targets CD20, a B-cell-specific surface antigen. The amount in milk is very low. It is also likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal.[1-3] Numerous breastfed infants apparently experienced no adverse effects during maternal use of rituximab, including no adverse effect on the CD19 +B cell count. The manufacturer recommends that breastfeeding be discontinued during rituximab therapy and for 6 months after the last dose. However, the American College of Rheumatology and others consider rituximab to be acceptable for use during breastfeeding;[4-7] however, waiting for at least 2 weeks postpartum to resume therapy may minimize transfer to the infant.[7] Breastfeeding can resume after the injection. One group recommends waiting for 4 hours after the pre-injection antihistamine dose before resuming breastfeeding.[7]