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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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Krypton Kr 81m

Last Revision: June 30, 2019.

Estimated reading time: 1 minute

CASRN: 15678-91-8

Chemical structure

Drug Levels and Effects

Summary of Use during Lactation

Information in this record refers to the use of krypton Kr 81m as a diagnostic agent. The International Commission on Radiological Protection and other experts state that breastfeeding need not be interrupted after administration of krypton Kr 81m gas.[1][2]

Drug Levels

Krypton 81m is an inert gas that is a gamma emitter with a principal photon energy of 0.19 MeV. Because of its rapid decay, the effective half-time of lung elimination is equal to the physical half-life of 13.1 seconds. Peripheral krypton 81m radioactivity is exhaled after the first passage through the lungs

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.


Parker JA, Coleman RE, Grady E et al. SNM practice guideline for lung scintigraphy 4.0. J Nucl Med Technol. 2012;40:57-65. [PubMed: 22282651]
Mattsson S, Johansson L, Leide Svegborn S et al. Radiation dose to patients from radiopharmaceuticals: A compendium of current information related to frequently used substances. Annex D. Recommendations on breast-feeding interruptions. Ann ICRP. 2015;44 (2 Suppl):319-21. [PubMed: 26069086]

Substance Identification

Substance Name

Krypton Kr 81m

CAS Registry Number


Drug Class

  • Breast Feeding
  • Radiopharmaceuticals
  • Krypton Radioisotopes
  • Diagnostic Agents

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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