List of benzimidazole opioids

Benzimidazole opioids, also known as nitazenes, are a class of synthetic opioids with an unusual benzimidazole structure; These chemicals are often called opioid NPS (or opioid New Psychoactive Substances).

The best known of these opioids is etonitazene. Benzimidazole opioids bind the mu-opioid receptor and may show potency up to several hundred times that of morphine.

These opioids have been used in research, and also are being used for drug abuse. Isotonitazine has been implicated in opioid overdose deaths in Europe, Canada, and the United States beginning in 2019.

List of benzimidazole opioids

• Nitazene; Ring substitution, hydrogen. The chemical structure can be drawn, as follows,
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Drug name	Ring substitution	Potency in comparison to morphine	More info	Chemical structure
Etonitazepyne	4-ethoxy
Etonitazepipne	4-ethoxy	190
Etonitazene morpholine analogue	4-ethox
Protonitazene
Protonitazepyne	4-(n-propoxy)		Pubchem
Isotonitazene	4-isopropoxy		Pubchem
Isotonitazepyne	4-isopropoxy		Pubchem
N-Desethylisotonitazene	4-isopropoxy	~1000 times stronger	Pubchem
Butonitazene	4-butoxy	5	Pubchem
Etoetonitazene	4-ethoxyethoxy	50	Pubchem
Flunitazene	4-fluoro	As potent as morphine	Pubchem
Clonitazene	4-chloro	3	Pubchem

• Metodesnitazene (Metazene); Ring substitution, 4-methoxy; Structural formula,

• Etodesnitazene (Etazene); 4-ethoxy.

• Metonitazene, 4-methoxy.

• Etonitazene, 4-ethoxy.

• N-Desethyletonitazene (NDE); 4-ethoxy.

• Etomethazene, 4-ethoxy.

• Etonitazene 5-cyano analogue (Etocyanazene). 4-ethoxy,

• Etonitazene 5-acetyl analogue (Etoacetazene). 4-ethoxy;