The Basics
What is Iobenguane I 123?
Used to find certain kinds of cancer of the adrenal glands (eg, pheochromocytoma, neuroblastoma).
Brand names for Iobenguane I 123
Adreview
How Iobenguane I 123 is classified
Radiopharmaceuticals, Iodine Radioisotopes, Diagnostic Agents
Iobenguane I 123 During Pregnancy
Iobenguane I 123 pregnancy category
Category CNote 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 123 while pregnant
Radioactive iodine products cross the placenta and can permanently impair fetal thyroid function. Administration of an appropriate thyroid blocking agent is recommended before use of AdreView in a pregnant woman to protect the woman and fetus from accumulation of I 123 [see DOSAGE AND ADMINISTRATION ]. There are no available data on AdreView use in pregnant women to evaluate for a drug-associated risk of major birth defects, miscarriage or adverse maternal or fetal outcomes. Animal reproduction studies have not been conducted with iobenguane I 123. All radiopharmaceuticals have the potential to cause fetal harm depending on the fetal stage of development and the magnitude of the radiation dose. Advise pregnant women of the potential risks of fetal exposure to radiation doses with administration of AdreView. AdreView contains 10.3 mg/mL of benzyl alcohol. Because benzyl alcohol is rapidly metabolized by a pregnant woman, benzyl alcohol exposure in the fetus is unlikely. However, adverse reactions have occurred in premature neonates and low birth weight infants who received intravenously administered benzyl alcohol-containing drugs [see WARNINGS AND PRECAUTIONS and Pediatric Use]. The estimated background risk of major birth defects and miscarriage for the indicated population(s) is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.
Taking Iobenguane I 123 While Breastfeeding
What are recommendations for lactation if you're taking Iobenguane I 123?
Information in this record refers to the use of iobenguane I 123 (I 123 meta-iodobenzylguanidine; I 123 MIBG) as a diagnostic agent. The United States Nuclear Regulatory Commission states that breastfeeding should be interrupted after administration of I 123 MIBG to a nursing mother. The duration of breastfeeding interruption depends on the dose administered (see table).[1][2] These values apparently refer to uncontaminated I 123. With contamination of I 124 or I 125, the interruption period is longer. Some international agencies recommend that breastfeeding should be interrupted for more than 3 weeks following diagnostic use of sodium iodide I 123.[3][4] This long period usually will result in permanent discontinuation of breastfeeding for this infant. During the period of interruption, the breasts should be emptied regularly and completely. If the mother has expressed and saved milk prior to the examination, she can feed it to the infant during the period of nursing interruption.[5][6][7] The milk that is pumped by the mother during the time of breastfeeding interruption can either be discarded or stored refrigerated and given to the infant after 10 physical half-lives, or about 5.5 days, have elapsed. Mothers concerned about the level of radioactivity in their milk could ask to have it tested at a nuclear medicine facility at their hospital. When the radioactivity is at a safe level she may resume breastfeeding. A method for measuring milk radioactivity and determining the time when a mother can safely resume breastfeeding has been published.[8]
| Dose | Duration of Interruption |
|---|---|
| 400 MBq (10.8 mCi) | 40-48 hours[2][7] |
| 370 MBq (10 mCi) | 24 hours[1] |
| 150 MBq (4 mCi) | 12 hours[1] |
Maternal / infant drug levels
Information in this record refers to the use of iobenguane I 123 (I 123 meta-iodobenzylguanidine; I 123 MIBG) as a diagnostic agent. The United States Nuclear Regulatory Commission states that breastfeeding should be interrupted after administration of I 123 MIBG to a nursing mother. The duration of breastfeeding interruption depends on the dose administered (see table).[1][2] These values apparently refer to uncontaminated I 123. With contamination of I 124 or I 125, the interruption period is longer. Some international agencies recommend that breastfeeding should be interrupted for more than 3 weeks following diagnostic use of sodium iodide I 123.[3][4] This long period usually will result in permanent discontinuation of breastfeeding for this infant. During the period of interruption, the breasts should be emptied regularly and completely. If the mother has expressed and saved milk prior to the examination, she can feed it to the infant during the period of nursing interruption.[5][6][7] The milk that is pumped by the mother during the time of breastfeeding interruption can either be discarded or stored refrigerated and given to the infant after 10 physical half-lives, or about 5.5 days, have elapsed. Mothers concerned about the level of radioactivity in their milk could ask to have it tested at a nuclear medicine facility at their hospital. When the radioactivity is at a safe level she may resume breastfeeding. A method for measuring milk radioactivity and determining the time when a mother can safely resume breastfeeding has been published.[8]
| Dose | Duration of Interruption |
|---|---|
| 400 MBq (10.8 mCi) | 40-48 hours[2][7] |
| 370 MBq (10 mCi) | 24 hours[1] |
| 150 MBq (4 mCi) | 12 hours[1] |
Possible effects of Iobenguane I 123 on milk supply
Relevant published information was not found as of the revision date.
Possible alternatives to Iobenguane I 123
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. 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/
2. Bombardieri E, Giammarile F, Aktolun C et al. 131I/123I-metaiodobenzylguanidine (mIBG) scintigraphy: procedure guidelines for tumour imaging. Eur J Nucl Med Mol Imaging. 2010;37:2436-46. PMID: 20644928
3. 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
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. Mountford PJ, Coakley AJ. A review of the secretion of radioactivity in human breast milk: data, quantitative analysis and recommendations. Nucl Med Commun. 1989;10:15-27. PMID: 2645546
6. Early PJ, Sodee DB. Principles and practice of nuclear medicine. 2nd ed. St. Louis. Mosby-Year Book, Inc. 1995:1380-1.
7. 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
8. Stabin MG, Breitz HB. Breast milk excretion of radiopharmaceuticals: mechanisms, findings, and radiation dosimetry. J Nucl Med. 2000;41:863-73. PMID: 10809203
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.
