[Clinical challenges and toxicology of nitazenes].

Nitazenes are 2-benzylbenzimidazole opioids never approved for medical use. They are highly potent, up to 500-fold stronger than heroin, and overdoses may require higher naloxone doses compared with overdoses caused by other opioids. They are found on the illicit drug market, but their presence in Denmark - particularly in counterfeit tablets - appears to be limited. Fatal cases have occurred, and forensic detection is challenged by very low lethal concentrations. Collaboration between authorities, clinicians and forensic toxicologists is crucial to prevent nitazene-related deaths in Denmark.