Klin Farmakol Farm. 2025;39(3):171-173 | DOI: 10.36290/far.2025.061

Nitazenes and other opioid receptor superagonists

Jitka Rychlíčková^{1, 2}, Ema Kunová³

¹ Farmakologický ústav, Lékařská fakulta, Masarykova univerzita, Brno

² Fakultní nemocnice u sv. Anny v Brně

³ Farmaceutická fakulta, Masarykova univerzita, Brno

Nitazenes and spirochlorphine are synthetic opioids that have been of interest in recent years in relation to unintentional overdoses with non-fatal and fatal consequences. These substances are potent agonists, predominantly of µ-opioid receptors, and exhibit a similar potency to fentanyl. The diagnosis of overdose is complicated by the inability to detect them with standard opioid screening tests. The available literature on the treatment of nitazene and spirochlorphine intoxication is limited. The objective of this article is to highlight the existence of these agents, summarise the known information on their pharmacology, and point out possible bottlenecks in the diagnosis and treatment of intoxication.

Keywords: nitazenes, spirochlorphine, novel psychoactive substances, naloxone, screening test.

Accepted: October 23, 2025; Published: October 30, 2025  Show citation