Nitazenes are highly potent synthetic opioids that are an emerging drug of concern in Australia and overseas. Opioids are drugs that bind to opioid receptors in the brain, as well as drugs related to the opium poppy plant – either natural (for example oxycodone and morphine), or synthetic (such as nitazenes and fentanyl) [1,2].
Nitazenes were first developed in the late 1950s with the intention to be used therapeutically as analgesics; however, they were never approved for pharmaceutical use due to their high potency and safety concerns [1,2]. Nitazenes can be up to 1000 times more potent than morphine and other opioids, and ten times more potent than fentanyl (this varies according to the class of nitazine) [1-3]. Nitazenes have been found in forms such as white powder, crystalline solids, or brown/yellow powder [2].
| Nitazene | Strength Compared to Morphine |
| Butonitazene | 5 |
| Etodesnitazene | 70 |
| Metonitazene | 100 |
| Protonitazene | 200 |
| Isotonitazene | 500 |
| Etonitazene | 1000 |
Source: NCCRED Briefing – Nitazene toxicity in Australia [3]
What are the effects of nitazenes?
As with any drug, there are risks involved and it’s important to be aware of them, especially considering the potency of nitazenes.
Effects of nitazenes vary according to the individual, strength and amount taken, environment and other circumstances, but short-term effects include [2,4]:
- Itchiness
- Nausea and vomiting
- Fever and sweating
- Headache
- Pin-point pupils
- Confusion
- Slow breathing and heart rate
- Euphoria
- Drowsiness and clumsiness
- Pain relief
- Reduced stress
As nitazenes are relatively new on the illicit drug market, their long-term effects haven’t been researched enough to understand all the risks involved; but they’re considered to be similar to other opioids.
These include [2,4]:
- Dependence
- Withdrawal
- Damage to vital organs such as the lungs, brain and heart
- Increased tolerance (requiring higher doses to feel pain relief)
- Constipation
- Depression
Nitazenes have a high potential for tolerance and dependence, and even a very small dose of nitazenes can cause overdose due to its strength.
Signs of overdose [2,4]:
- Slow/shallow breathing
- Bluish/greyish lips and complexion
- Loss of consciousness or responsiveness
- Vomiting
- Coma
- Death
Nitazene overdose can be fatal. If you or someone else is exhibiting these symptoms, call an ambulance on triple zero (000). If caught in time, naloxone can be administered to temporarily reverse the effects of opioid overdose (and is free with no prescription under the Australian government-funded Take Home Naloxone (THN) program). See more information on this here.
Nitazenes in Australia and overseas
There has been an increase in nitazene toxicity in the Australian illicit drug supply since the first reports in 2021 [3]. Isotonitazene (a class of nitazene) was first detected in Europe and North America in 2019 as a drug class of concern, where they continue to be associated with mortalities and harms. The rise of nitazenes is partly due to the reduction in opium production in Afghanistan (following a poppy cultivation ban), and the subsequent reliance on synthetic opioids in international markets, including Australia [3]. Public drug alerts concerning nitazene related harms (including death) have been released across the ACT, NSW, QLD, SA, and Victoria, with nitazenes also being detected in Western Australia and the Northern Territory. In April 2024, NSW Health issued a public health warning after around 20 overdoses were reported in Nepean Blue Mountains Local Health District, where nitazenes were detected in people who believed they were using heroin [5].
This mixing of nitazenes into other drugs is of increasing concern. Recently, nitazenes have been found in drugs sold as heroin, oxycodone, MDMA, cocaine, alprazolam (known as “Xanax”) and ketamine [3,4]. Just recently, on the 26th November 2024, a drug alert was released to warn that nitazenes have been causing overdose in people who have taken fake oxycodone tablets. Other public health alerts have been issued about protonitazene contaminating oxycodone and cocaine across Australia. As nitazenes can be much more potent than the drugs people think they are taking, this increases the risk of overdose and harms [4]. Further, as nitazenes are illicit and unregulated, there is no way of knowing what class of nitazene is present (and in turn how potent), or how much is being taken.
Harm reduction initiatives
Naloxone distribution (see above) and public awareness efforts (such as health warnings and public drug alerts) are issued when nitazenes are detected in drug supply, and are being implemented as harm reduction and early detection strategies. This also includes clinical alerts to medical professionals, which highlight the dangers of nitazenes and possible requirement for multiple naloxone doses (as nitazenes can last longer in the body than heroin and naloxone) [6].
Nitazene Test Strips are also a harm reduction strategy used to detect nitazenes in various substances, with the aim to prevent accidental overdoses and increase awareness of drug supplies being adulterated with other dangerous substances [7]. CanTEST is a free and confidential health and drug harm reduction service in Canberra, ACT, which tests drugs for substance adulteration.
The Australian Federal Police (AFP) and Australian Border Force (ABF) have also increased efforts to intercept nitazenes at the border. Recent reports show a rise in attempted imports of nitazenes, prompting tighter surveillance and public warnings [6].
These are all critical strategies to reduce drug-associated harms, but the greatest tool is education, so that people are informed of the risks and harms can be prevented.
If you’re concerned about yourself or a loved one, help is available.
Call the National Alcohol and Other Drug Hotline on 1800 250 015 for free and confidential support about alcohol and other drugs.
An example of naloxone packaging
References
[1] P. Jr et al., “Old Drugs and New Challenges: A Narrative Review of Nitazenes,” Cureus, vol. 15, no. 6, Jun. 2023, doi: https://doi.org/10.7759/cureus.40736. [2] Alcohol and Drug Foundation, “Nitazenes,” adf.org.au, Jul. 19, 2024. https://adf.org.au/drug-facts/nitazenes/ [3] The National Centre for Clinical Research on Emerging Drugs (NCCRED), “Increasing reports of nitazene toxicity in Australia,” Apr. 2024. Available: https://nccred.org.au/uploads/documents/Nitazenes-Emerging-Drug-Briefing.pdf [4] Positive Choices, “What are opioids?,” 2024. Available: https://positivechoices.org.au/teachers/opioids/pdf/ [5] NSW Health, “Public health warning: severe opioid overdoses related to nitazene use,” NSW Health, 2024. https://www.health.nsw.gov.au/news/Pages/20240529_00.aspx [6] Your Room, “What are nitazenes?,” Your Room, 2024. https://yourroom.health.nsw.gov.au/whats-new/Pages/-what-are-nitazenes.aspx [7] Drug Policy Australia, “Nitazenes and Synthetic Opioids in Australia,” Drug Policy Australia, 2024. https://www.drugpolicy.org.au/nitazene_and_synthetic_opioids_in_australia
Author: Francesca Wallis
