Postmortem distribution of isotonitazene and its three metabolites in the first lethal case observed in France

To the best of our knowledge, this is the first reported fatal IZN intoxication with comprehensive postmortem analysis, including quantification of active metabolites in solid organs. The case is marked by low peripheral blood levels, extensive redistribution, and selective tissue accumulation. Active metabolites: N-desethyl IZN, 4'-hydroxy-nitazene, and 5-amino IZN showed distinct distribution and elimination profiles. These findings highlight the high potency, rapid metabolism, and complex toxicokinetic of IZN.