From fentanyl analogues to nitazenes: a time-resolved analysis of policy-driven displacement in the synthetic opioid landscape

Gören İ. E.

3rd International Kosovo Academic Research Congress, Priştine, Kosova, 1 - 03 Ağustos 2026, ss.1, (Tam Metin Bildiri)

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Basıldığı Şehir: Priştine
  • Basıldığı Ülke: Kosova
  • Sayfa Sayıları: ss.1
  • Ankara Üniversitesi Adresli: Evet

Özet

Class-wide control of fentanyl-related substances was introduced to limit highly potent fentanyl analogues. China implemented class-wide scheduling on 1 May 2019, after which chemically distinct benzimidazole opioids, particularly nitazenes, became increasingly visible in early-warning and forensic systems. This study evaluated whether the composition of emerging synthetic opioids changed after the 2019 intervention and whether the pattern was reflected across European, global, and United States surveillance indicators. Annual counts of novel opioids first formally notified to the European Union Early Warning System between 2009 and 2025 were classified as fentanyl derivatives, nitazenes, or orphines. The pre-intervention period (2009–2018) was compared with the post-intervention period (2019–2025). Changes in fentanyl–nitazene composition were assessed using Fisher’s exact test. UNODC Early Warning Advisory indicators and selected NFLIS-Drug data were used for contextual triangulation. Surveillance streams were interpreted separately and were not pooled. During 2009–2018, 34 fentanyl derivatives and no nitazenes were first notified. During 2019–2025, only four additional fentanyl derivatives were notified, compared with 25 nitazenes. The class-composition change was significant (p<0.001). Mean annual fentanyl-derivative notifications decreased from 3.40 to 0.57, whereas mean annual nitazene notifications increased from 0 to 3.57. Nitazenes represented 86.2% of combined fentanyl-derivative and nitazene notifications after 2019 and peaked in 2024 (n=7). By January 2025, 26 nitazenes had been reported from 30 countries. UNODC recorded 292 nitazene-associated toxicology cases during 2019–2024, 82% of which were postmortem. However, NFLIS-Drug reported 71 nitazene identifications versus 6,249 fentanyl and fentanyl-related identifications in the first quarter of 2025. The post-2019 landscape showed a marked shift from fentanyl-analogue proliferation toward nitazenes. The timing is consistent with policy-associated structural displacement, although surveillance data cannot establish direct causal substitution. Early-warning systems should monitor scaffold-level transitions and anticipate migration toward chemically distinct opioid classes.