Four people have been hospitalised across Sydney with severe opioid overdose caused by nitazenes.

People who thought they were taking etazene were taking a more potent nitazene (protonitazepyne*) and a potent novel benzodiazepine (bromazolam).

Another potent nitazene (protonitazene) is suspected to have been present in either cocaine or ketamine.

* also known as N-pyrrolidino protonitazene

Last updated: 29 May 2024


Know the risks

  • Nitazenes are synthetic opioids that are stronger and may be longer acting than many other opioids. They are up to 500 times more potent than heroin.
  • Nitazenes are dangerous and vary in strength – some nitazenes are so strong that there is no safe dose. The purity of the drug can also vary within a single batch.
  • The risks of overdose are increased if you:
    • Use drugs alone.
    • Use nitazenes or other opioids if you have not used them before.
    • Use drugs again after a break.
    • Use with other drugs (like alcohol, benzodiazepines, ketamine, or GHB).
    • Use a new batch.
  • Naloxone can temporarily reverse an overdose from opioids. Nitazenes often require multiple doses of naloxone. Always ring an ambulance. The effects of naloxone may wear off, and ongoing doses and hospital treatment may be needed.
  • Nitazenes have also been found in vapes and counterfeit tablets such as benzodiazepines, and in drugs thought to be heroin or MDMA.
  • Fentanyl test strips do not detect nitazenes.

Effects to look out for

  • Pinpoint pupils, drowsiness, loss of consciousness, slow breathing/snoring or skin turning blue/grey.
  • If you or others experience these symptoms, get help immediately.

Getting help

If you or your friends see the warning signs of overdose:

  • Seek help immediately from your nearest emergency department or call Triple Zero (000). You won’t get into trouble for seeking medical care.
  • Start CPR if someone is not breathing.
  • Use naloxone if you have it. Call ‘000’ even if naloxone has been given.

Take Home Naloxone Program

  • Naloxone is a life-saving medicine that can temporarily reverse an opioid overdose. Naloxone is available in a very easy to use nasal spray and as a pre-filled injection.
  • You should carry naloxone if:
    • You are using drugs such as cocaine, ketamine, methamphetamine, MDMA or opioids.
    • You are hosting or going to a party where drugs will be present. 
  • If you might experience or witness an opioid overdose you can get naloxone for free without a prescription in NSW from some community pharmacies, needle & syringe programs, opioid treatment services and NUAA.
  • Visit Your Room for participating sites and more information on take-home naloxone.
  • NUAA can mail you naloxone in a discreet package. Order via their online shop: or call (02) 9171 6650.

Support and advice

For free and confidential advice:

Current as at: Wednesday 29 May 2024