Etazene

Substance identification
Etazene (IUPAC chemical name: 2-[(4-Ethoxyphenyl)methyl]-N,N-diethyl-1H- benzimidazole-1-ethanamine), also known as etodesnitazene, is a benzimidazole- derived synthetic opioid. Etazene has been described as a grey crystalline, light- yellow, white or beige powder. It has also been identified in liquid form and in falsified pharmaceutical opioids.

WHO review history
Etazene has not been formally reviewed by WHO and is not currently under international control. Information was brought to the attention of WHO that this substance is manufactured clandestinely, poses a risk to public health and has no recognized therapeutic use.

Similarity to known substances and effects on the central nervous system
Etazene binds to the µ-opioid receptor with a potency greater than that of morphine. In studies of analgesia in animals, etazene had full agonist effects, with a potency between those of morphine and fentanyl, which are both controlled under Schedule I of the Single Convention on Narcotic Drugs, 1961. The effects of etazene are reversed by the opioid antagonist, naltrexone.

Dependence potential
No controlled studies of the dependence potential of etazene in animals or in humans have been reported. As it is a potent µ-opioid receptor agonist, it would be expected to produce dependence similar to other opioids, such as morphine and fentanyl. Online self-reports described tolerance with repeated use of etazene.

Actual abuse and/or evidence of likelihood of abuse
In an animal model predictive of abuse potential, etazene had effects similar to those of morphine. No controlled studies have been conducted of the abuse potential of etazene in humans, but, as it is a potent µ-opioid receptor agonist, it would be expected to produce euphoria and other effects predictive of high abuse liability. Online self-reports support its euphoric and other opioid effects.

Seizures of etazene have been reported in multiple countries in two regions.

A number of deaths have occurred in which the presence of etazene was confirmed analytically and in which it was considered to have contributed to death, although other substances were also identified in these cases.

Therapeutic usefulness
Etazene is not known to have any therapeutic use.

Recommendation
Etazene (IUPAC chemical name: 2-[(4-Ethoxyphenyl)methyl]-N,N-diethyl-1H- benzimidazole-1-ethanamine), also known as etodesnitazene, is a synthetic opioid that is liable to abuse and produces ill effects similar to other opioids that are controlled under Schedule I of the 1961 Single Convention on Narcotic Drugs. Its use has been reported in a number of countries and has been associated with adverse effects, including death. It has no known therapeutic use and poses a significant risk to public health.

Recommendation: The Committee recommended that etazene (IUPAC chemical name: 2-[(4-Ethoxyphenyl)methyl]-N,N-diethyl-1H-benzimidazole-1- ethanamine), also known as etodesnitazene, be added to Schedule I of the 1961 Single Convention on Narcotic Drugs.