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Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-.

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Drugs and Lactation Database (LactMed) [Internet].

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Sodium Phosphate P 32

Last Revision: August 17, 2020.

Estimated reading time: 1 minute

CASRN: 7635-46-3

image 135027861 in the ncbi pubchem database

Drug Levels and Effects

Summary of Use during Lactation

Information in this record refers to the use of sodium phosphate P 32 as a therapeutic agent. No information is available on the use of sodium phosphate P 32 during breastfeeding. The European Association of Nuclear Medicine recommends using other modalities to treat polycythemia vera and essential thrombocytopenia in patients under 60 to 65 years of age and states that the drug is contraindicated in nursing mothers.[1] If a nursing mother is given sodium phosphate P 32 systemically, breastfeeding should be discontinued permanently for this child.

Drug Levels

Phosphorus P 32 decays by beta emission with an energy of 1.709 MeV and a half-life of 14.3 days. Radioactivity declines with an effective half-life of 11 days after injection of sodium phosphate P 32.[2]

Maternal Levels. A mother was given 37 MBq of phosphorus P 32 intravenously for diagnosis of a malignant tumor in the eye. Two breastmilk samples were collected, one a few hours after the injection and another on the following day. The first milk sample contained 0.005% of the injected radioactivity per liter and the second day's milk contained 0.016% of the injected radioactivity per liter.[2]

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

Effects in Breastfed Infants

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

Effects on Lactation and Breastmilk

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


Tennvall J, Brans B. EANM procedure guideline for 32P phosphate treatment of myeloproliferative diseases. Eur J Nucl Med Mol Imaging. 2007;34:1324–7. [PubMed: 17396258]
Mountford PJ, Wells CP, Hall FM, et al. Potential radiation dose to a breast-fed infant following administration of sodium 32P-phosphate to the mother. Nucl Med Commun. 1984;5:473–6. [PubMed: 6531156]

Substance Identification

Substance Name

Sodium Phosphate P 32

CAS Registry Number


Drug Class

Breast Feeding



Phosphorus Radioisotopes

Disclaimer: Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.


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