I 125-Labeled Human Serum Albumin

Drug Levels and Effects:

Summary of Use during Lactation:

Elective diagnostic nuclear medicine procedures should be delayed until the patient is no longer breastfeeding.[1] Information in this record refers to the use of 125-labeledhumanserum albumin (I 125 HSA) as a diagnostic agent. The International Commission on Radiological Protection states that breastfeeding should be interrupted for more than 3 weeks following diagnostic use of I 125 HSA. This usually will result in permanent discontinuation of breastfeeding for this infant. Mothers could ask to have their milk tested at a nuclear medicine facility at their hospital and when milk radioactivity will give the infant a dose below 1 mSv, they may safely resume breastfeeding.[2] A method for measuring milk radioactivity and determining the time when a mother can safely resume breastfeeding has been published.[3]

Drug Levels:

I 125 is a low-energy pure gamma emitter with a physical half-life of 60.14 days.[3] Iodide is actively secreted into breastmilk and actively taken up by the mother's and infant's thyroid glands.

Effects in Breastfed Infants:

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

Possible Effects on Lactation:

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


1. Parker JA, Daube-Witherspoon ME, Graham LS et al. Procedure guideline for general imaging: 3.0. Society of Nuclear Medicine. 2004. http://interactive.snm.org/docs/General_Imaging_v3.0.pdf
2. ICRP. Radiation dose to patients from radiopharmaceuticals. Addendum 3 to ICRP Publication 53. ICRP Publication 106. Annex D. Ann ICRP. 2008;38:163-84. PMID:19154964
3. Howe DB, Beardsley M, Bakhsh S. Appendix U. Model procedure for release of patients orhumanresearch subjects administered radioactive materials. In, NUREG-1556. Consolidated guidance about materials licenses. Program-specific guidance about medical use licenses. Final report. U.S. Nuclear Regulatory Commission Office of Nuclear Material Safety and Safeguards. 2008;9, Rev. 2. http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1556/v9/r2/

Substance Identification:

Substance Name:

I 125-LabeledHumanSerum Albumin

Drug Class:

  • Radiopharmaceuticals

  • Iodine Radioisotopes

  • Serum Albumin, Radio-Iodinated

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

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