Tositumomab I 131 is no longer marketed in the US. Information in this record refers to the use of tositumomab I 131 as a therapeutic agent. No information is available on the use of tositumomab I 131 during breastfeeding. Because of the potential for serious adverse reactions in nursing infants, the manufacturer and expert opinion recommend not administering the drug in women who wish to continue breastfeeding.[1] If the drug is given, breastfeeding should be discontinued. Parents should limit close contact with their infants and small children after therapeutic tositumomab I 131 administration. Suggested contact times by one group are 30 minutes per day or less of contact at a distance of 2 meters or less for a period of 6 to 23 days.[2] Another group suggests avoiding contact with small children at a distance of 10 cm for an average of 8.1 days (range 3.5 to 12.9 days).[3] Additionally, nursing mothers may have excessive I 131 uptake by the breasts, so they should receive potassium iodide or Lugol's solution before receiving tositumomab I 131 to block uptake by the breasts and thyroid.
Nursing mothers should not work with substances containing I 131 in their workplace.[4]