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# Guide Microdose Radiopharm Diagnostic Drugs
- URL: https://www.fdaweb.com/guide-microdose-radiopharm-diagnostic-drugs/
- Published: 2018-08-20T12:00:00.000Z
- Updated: 2026-09-15T00:26:55.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5142148

FDA has posted a [guidance](https://www.fda.gov/downloads/Drugs/GuidanceComplianceRegulatoryInformation/Guidances/UCM575453.pdf?ref=fdaweb.com) on “Microdose Radiopharmaceutical Diagnostic Drugs: Nonclinical Study Recommendations.” The document is intended to assist sponsors regarding nonclinical studies recommended to support human clinical trials and marketing applications. It discusses how to refine nonclinical study recommendations for this class of drug given its unique characteristics ( e.g., microdose, radiolabeled, single \[or infrequent\] use, clinical use setting, the agency’s nonclinical and clinical safety experience with these drugs). Additionally, the guidance is intended to help sponsors reduce the use of animals and reduce the use of drug development resources.