Description

Nitazenes are a group of synthetic opioids that have emerged in recent years and are analogues of the internationally controlled substances clonitazene and etonitazene. Six nitazenes are currently under Schedule I of the Single Convention on Narcotic Drugs of 1961.

The first nitazene reported to UNODC, isotonitazene, emerged in 2019 and since then 19 substances have emerged. This family of synthetic opioids was initially developed in an attempt to access safer classes of opioid analgesics, but in fact, the substances discovered had a potency several times higher than morphine (e.g., etonitazene, 70x and isotonitazene, 500x).


Chemical structure

Nitazenes can be differentiated into two sub-families, which include nitrobenzimidazoles (e.g., isotonitazene), and benzimidazoles (e.g., metodesnitazene) (Figure 1).

Figure 1: Common nitazene NPS


Note: The structural differences are highlighted in red.
Source: UNODC, The challenge of New Psychoactive Substances - A technical update (United Nations publication, 2024).

Commonly used forms

The commonly reported routes of administration of nitazenes are vaping intravenous sublingual and intranasally via spray or insufflation. Figure 2 shows opioid receptor agonists commonly used forms.

Figure 2: Opioid receptor agonists commonly used forms



Source: UNODC, The challenge of New Psychoactive Substances - A technical update (United Nations publication, 2024).


Reported adverse effects

The clinical toxicological properties of many nitazenes have not been studied directly. There are few reports from online user forums on the acute and chronic physical and psychological effects. The adverse effects align with those commonly reported for other synthetic opioid NPS such as incoordination, dizziness, drowsiness, mental confusion, sedation, and profound intoxication. Figure 3 shows reported effects of opioid receptor agonists.

Figure 3: Reported effects of opioid receptor agonists



Source: UNODC, The challenge of New Psychoactive Substances - A technical update (United Nations publication, 2024).


References

UNODC, The challenge of New Psychoactive Substances - A technical update (United Nations publication, 2024).

UNODC, Terminology and Information on Drugs, Third Edition (United Nations publication Sales No. E.16.XI.8)

UNODC, Early Warning Advisory on New Psychoactive Substances Dashboard, accessed 27 September 2024.

Last update: 30/09/2024