Recently, nitazenes (isotonitaze or “iso”, metonitazene, and protonitazene) – a class of synthetic opioids – were detected in drug samples in Nevada County. The high potency of nitazenes combined with inexperience with dosing, a lack of awareness of nitazenes being present in the local drug supply, and the mixing of nitazenes into drugs that already contain fentanyl increases overdose risk.

What are Nitazenes?

Nitazenes are a strong class of synthetic opioids that are increasingly found in the U.S. drug supply. The class of opioids consists of three drugs (isotonitazene or “iso”, metonitazene, and protonitazene) and range from less potent than fentanyl to more potent than fentanyl. Nitazenes cause opioid effects, and the risk of overdose from nitazene exposure is high.

Naloxone (Narcan) is effective in treating nitazene-related opioid overdoses. The signs of possible opioid overdose are listed below:

  • Non-responsive to touch or verbal stimulus
  • Unconscious
  • No breathing or shallow breathing
  • Blue lips or fingernails
  • Grey or ashen skin color
  • Pinpoint pupils, or very small pupils, indicate opioid presence in the body

Does naloxone work on nitazenes?

Yes, there are no naloxone-resistant opioids, and that includes nitazenes.

Due to the strength of nitazenes, including iso, it may take more than one dose of naloxone to reverse an overdose. Follow usual naloxone administration guidelines, including:

  • Wait 2-3 minutes between doses and provide rescue breaths until the person overdosing resumes breathing or first responders arrive.
  • Don’t use alone, if possible, or call the Never Use Alone hotline: 877-696-1996.
  • Avoid using nitazenes with other opioids, alcohol, benzodiazepines and other drugs that slow beathing.

Can I use fentanyl test strips to test for nitazenes?

No, fentanyl test strips will not detect nitazenes in substances. Nitazenes have a different structure than other opioid classes and are not detected using standard urine drug testing or fentanyl testing strips.
Always carry naloxone, even if a test strip reads as “negative” for the presence of fentanyl or opioids.

Additional Resources

Rhode Island testRI Fact Sheet on Nitazenes

City of Philadelphia Department of Public Health Alert

WHO Report on Isotonitazene