The Basics
What is Iobenguane I 131?
Used to treat certain cancers (pheochromocytoma, paraganglioma).
Brand names for Iobenguane I 131
Azedra
How Iobenguane I 131 is classified
Radiopharmaceuticals, Iodine Radioisotopes, Diagnostic Agents
Iobenguane I 131 During Pregnancy
Iobenguane I 131 pregnancy category
Category N/ANote that the FDA has deprecated the use of pregnancy categories, so for some medications, this information isn’t available. We still think it’s useful to list historical info, however, given what a common proxy this has been in the past.
What we know about taking Iobenguane I 131 while pregnant
N/A
Taking Iobenguane I 131 While Breastfeeding
What are recommendations for lactation if you're taking Iobenguane I 131?
Information in this record refers to the use of iobenguane I 131 (I 131 meta-iodobenzylguanidine; I 131 MIBG) as a diagnostic agent. International agencies state that breastfeeding should be interrupted for more than 3 weeks following diagnostic use of I 131 MIBG.[1][2] After therapeutic dosages, the manufacturer recommends that breastfeeding should be withheld for 80 days after the final dose. These times usually result in permanent discontinuation of breastfeeding for this infant, and cessation of breastfeeding for the current infant is recommended by most experts.[1][3][4] Patients receiving iobenguane I 131usually receive potassium iodide prior to the diagnostic examination to block their thyroid gland’s uptake of the I-131 that is released from the I 131 MIBG. Iodide may interfere with the infant’s thyroid function. Nursing mothers should not work with substances containing I 131 in their workplace.[5]
Maternal / infant drug levels
Information in this record refers to the use of iobenguane I 131 (I 131 meta-iodobenzylguanidine; I 131 MIBG) as a diagnostic agent. International agencies state that breastfeeding should be interrupted for more than 3 weeks following diagnostic use of I 131 MIBG.[1][2] After therapeutic dosages, the manufacturer recommends that breastfeeding should be withheld for 80 days after the final dose. These times usually result in permanent discontinuation of breastfeeding for this infant, and cessation of breastfeeding for the current infant is recommended by most experts.[1][3][4] Patients receiving iobenguane I 131usually receive potassium iodide prior to the diagnostic examination to block their thyroid gland’s uptake of the I-131 that is released from the I 131 MIBG. Iodide may interfere with the infant’s thyroid function. Nursing mothers should not work with substances containing I 131 in their workplace.[5]
Possible effects of Iobenguane I 131 on milk supply
Relevant published information was not found as of the revision date.
Possible alternatives to Iobenguane I 131
None listed
List of References
Lactation sources: Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK501922/1. 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. PMID: 26069086
2. National Radiation Protection Board (UK). Administration of radioactive substances advisory committee. Notes for guidance on the clinical administration of radiopharmaceuticals and use of sealed radioactive sources. 2019. https://assets.publishing.service.gov.uk/government/…/file/…/ARSAC_NfG_2019.pdf
3. Bombardieri E, Giammarile F, Aktolun C L et al. 131I/123I-metaiodobenzylguanidine (mIBG) scintigraphy: procedure guidelines for tumour imaging. Eur J Nucl Med Mol Imaging. 2010;37:2436-46. PMID: 20644928
4. International Atomic Energy Agency. Radiation Protection and Safety in Medical Uses of Ionizing Radiation, IAEA Safety Standards Series No. SSG-46, IAEA, Vienna. 2018. https://www.iaea.org/publications/11102/radiation-protection-and-safety-in-medical-uses-of-ionizing-radiation
5. Almen A, Mattsson S. Radiological protection of foetuses and breast-fed children of occupationally exposed women in nuclear medicine – Challenges for hospitals. Phys Med. 2017;43:172-7. PMID: 28882410
6. Howe DB, Beardsley M, Bakhsh S. Appendix U. Model procedure for release of patients or human research 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/
Disclaimer: This material is provided for educational purposes only and is not intended for medical advice, diagnosis, or treatment. Consult your healthcare provider with any questions.
