Is Rituximab Safe in Breastfeeding

I am a breastfeeding mother and i want to know if it is safe to use Rituximab? Is Rituximab safe for nursing mother and child? Does Rituximab extracts into breast milk? Does Rituximab has any long term or short term side effects on infants? Can Rituximab influence milk supply or can Rituximab decrease milk supply in lactating mothers?

Monoclonal antibody which is an immunoglobulin G with anti-CD20 activity that contains 664 amino acids. Indicated for treatment of Rheumatoid Arthritis, Hodgkin Lymphoma and Chronic Lymphoid Leukemia. At latest update relevant data on breastfeeding were not found. Because of a high molecular weight, excretion into breast milk is very unlikely. Its low oral bioavailability makes that serum levels in the infant that could be originated from milk absorption are to be absent or scanty, except in premature infants or in the early period after birth in which gut absorption may be increased. Many reports have not shown harmful effects in the infant after long-lasting intrauterine exposure . However, despite it is thought to be safe while breastfeeding, and, until more data on this drug is available, in cases of Rheumatoid Arthritis a known safer alternative should be used.

Rituximab is a genetically engineered chimeric murine/human monoclonal antibody that targets CD20, a B-cell-specific surface antigen. Limited data indicate that the amount in milk is very low and absorption is unlikely because it is a protein with a molecular weight of 143,860, it is probably destroyed in the infant's gastrointestinal tract.[1][2] Although 2 breastfed infants apparently experienced no adverse effects during maternal use of rituximab, no long-term data are available. If rituximab is required by the mother, it is not a reason to discontinue breastfeeding.[3] Until more data become available, rituximab should be used with caution during breastfeeding, especially while nursing a newborn or preterm infant.[4][5][6] The manufacturer recommends that breastfeeding be discontinued during rituximab therapy and for 6 months after the last dose.

A woman received rituximab 375 mg/square meter once weekly for 4 weeks beginning at week 30 of gestation. Her infant was born at 40 weeks of gestation and was exclusively breastfed with no major health issues. At 4 months of age, the infant's B-cell population and immunoglobulin levels did not appear to be affected.[7] A woman received an IV infusion of 1000 mg of rituximab at about 3 months postpartum. Her infant who was fully breastfed had no serious infections during the lactation period and developed normally during a 1.5 year follow-up period.[2]