Nitazenes (benzimidazole opioids)

psilodex.org/m/nitazenes · data v2026.10.02

Clinical contraindication: Relative; Substantial clinical concern; the literature treats it as a reason for caution or deferral.
Best available evidence: Case reports; Also: mechanism only.
Half-life: Not recorded

Named in state rules?

CONot named

ORNot named

NMPending

Cite asPsilodex: nitazenes · v2026.10.02

Clinical data and state rules are separate facts. Both are shown; neither is a decision.

01 Interaction with psilocybin

CR · Th

Synthetic opioids that can match or far exceed fentanyl's potency, found in counterfeit pills and fentanyl mixtures, often unknown to the user. Opioids slow breathing, and effects stack with other sedatives. Naloxone reverses them, though multiple doses may be needed.

Human data with psilocybin: Case reports or surveys only

Evidence types on this record

CRCase reports or online surveys

ThMechanism only (theoretical)

02 Pharmacology relevant to psilocybin

1 listed · counted on reports

Sedating or CNS depressant: Slows the central nervous system: drowsiness, slower reactions and impaired coordination, and slowed breathing at high doses. Effects add with other sedating substances. Sources [5]

03 State rules

Plain-language summary · official text governs

CO4 CCR 755-1

Not named

No provision names this medication or its class.

Colorado · checked 2026-09-30

OROAR 333-333

Not named

No provision names this medication or its class.

Oregon · checked 2026-09-30

NM7.35.3 NMAC (proposed)

Pending

New Mexico's clinical rules (proposed 7.35.3 NMAC) are not final. No provision naming this medication has been found.

New Mexico · checked 2026-10-02

04 Conditions to ask about

None linked

No condition named in state rules is linked to this medication.

05 Sources

US Drug Enforcement Administration. 2025 National Drug Threat Assessment. May 2025. — nitazenes can match or surpass fentanyl potency; not approved for medical use (p. 28)
US Drug Enforcement Administration. State and Territory Report on Enduring and Emerging Threats (STREET): Nitazenes — an emerging threat of a diverse group of synthetic opioids (STR-002-25). September 2025. — isotonitazene, metonitazene, protonitazene most common; fake 'M-8' Dilaudid pills containing isotonitazene
Roberts A, Korona-Bailey J, Mukhopadhyay S. Notes from the field: nitazene-related deaths — Tennessee, 2019–2021. MMWR 2022;71(37):1196–1197. — Tennessee deaths 2019–2021; isotonitazene/protonitazene/etonitazene exceed fentanyl potency; naloxone effective but multiple doses may be needed
Vandeputte MM, Krotulski AJ, Walther D, et al. Pharmacological evaluation and forensic case series of N-pyrrolidino etonitazene (etonitazepyne), a newly emerging 2-benzylbenzimidazole 'nitazene' synthetic opioid. Arch Toxicol 2022;96(6):1845–1863. — N-pyrrolidino etonitazene: MOR potency ~10x fentanyl in vivo; 21 fatalities
Dahan A, Franko TS, Carroll JW, et al. Fact vs. fiction: naloxone in the treatment of opioid-induced respiratory depression in the current era of synthetic opioids. Front Public Health 2024;12:1346109. — opioid-induced respiratory depression; nitazenes increasingly in illicit supply

Record history

v2026.10.02First published.
2026-10-02Last reviewed against its sources.

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