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November 2021 – UNODC EWA: Synthetic opioids increase and diversify rapidly

VIENNA, Austria – November 2021: In 2020, new synthetic opioids were the group with the highest number of new psychoactive substances (NPS) reported for the first time (19 NPS) to the UNODC Early Warning Advisory on NPS, outnumbering the number of stimulants (17) and synthetic cannabinoids (13) reported for the first time in that year.

Figure 1: New developments – Synthetic opioids reported for the first time, 2014-2021*

Source: UNODC Early Warning Advisory on NPS, 2021. Note: Data for 2021 are preliminary.

Apart from fentanyl analogues and compounds of the “U” series, synthetic opioids belonging to a structurally different group known as “nitazenes” continue to be reported in the USA, Canada and Europe. “Nitazenes”, which were first reported to the UNODC EWA in 2019, may have a potency similar to fentanyl (Vandeputte et al., 2021) and thus pose a serious health risk. Isotonitazene, a “nitazene” that was first reported to UNODC in 2019, was placed under international control in 2020. The World Health Organization is currently reviewing metonitazene, another compound belonging to this group.

The continuing emergence of new and structurally divers synthetic opioids is a reason for concern because of the potentially severe health consequences associated with their use. Other challenges include their identification in the laboratory which requires, for example, a high analytical sensitivity as the concentrations of isotonitazene in biological samples are typically low to sub-nanograms per milliliter. In addition, newly emerging opioids may not be covered by existing national legislation, including generic legislation designed to control fentanyl analogues.

Figure 2: NPS reported for the first time in 2020 by effect group

Source: UNODC Early Warning Advisory on NPS, 2021.

For more information, please see:

UNODC, Global SMART Update Volume 24, The growing complexity of the opioid crisis (October 2021).

UNODC, Global SMART Update Volume 25, Regional diversity and the impact of scheduling on NPS trends (April 2021).

UNODC, WHO: Five New Psychoactive Substances to be considered for international control by 44th ECDD meeting, newsclip (July 2021).

UNODC, CND decision on international control of isotonitazene enters into force - remaining decisions will enter into force in December 2021, newsclip (June 2021).

UNODC, Recommended methods for the Identification and Analysis of Fentanyl and its Analogues in Biological Specimens (Vienna, 2017).

WHO, Critical review report: Isotonitazene (October 2020).

WHO, Critical review report: Metonitazene (October 2021).

Krotulski AJ, Papsun DM, Kacinko SL, Logan BK. Isotonitazene Quantitation and Metabolite Discovery in Authentic Forensic Casework. J Anal Toxicol., Vol. 44(6), pp. 521-530 (July 2020).

Krotulski AJ, Papsun DM, Walton SE, Logan BK. Metonitazene in the United States-Forensic toxicology assessment of a potent new synthetic opioid using liquid chromatography mass spectrometry. Drug Test Anal., Vol. 13(10), pp. 1697-1711 (June 2021).

Vandeputte MM, Van Uytfanghe K, Layle NK, St Germaine DM, Iula DM, Stove CP. Synthesis, Chemical Characterization, and μ-Opioid Receptor Activity Assessment of the Emerging Group of "Nitazene" 2-Benzylbenzimidazole Synthetic Opioids. ACS Chem Neurosci., Vol. 12(7), pp. 1241-1251 (April 2021).

***The Spanish translation of this news item is made possible thanks to a collaboration with OAS/CICAD, a partner of the UNODC EWA.***

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