Novel Deiodinase 2-Selective Inhibitors—Possible Reference Substances for Regulatory In Vitro Tests for Endocrine Disruptors and Drugs Targeting T3-Dependent Processes

Specific DIO2 inhibitors, such as the FDA-approved drugs racecadotril and ibrutinib and the tyrosine kinase inhibitor rociletinib, might serve as a future toolbox for reversible pharmacological interference with the local provision of DIO2-generated T3 from T4 during development, tissue regeneration, and various DIO2-dependent metabolic processes. Furthermore, they can serve as reference compounds for the development and validation of regulatory in vitro tests. Identified FDA-approved drugs warrant a closer look at potential disturbances of local TH availability.