A synthetic opioid 1000 times more potent than morphine sparks ‘wave of overdoses’ fears for SA

Injecting drug users are unwittingly playing Russian roulette, unaware if their dose has been laced with a super powerful and potentially deadly opioid, worried researchers warn.

A synthetic opioid 1000 times more potent than morphine is infiltrating Adelaide’s street drug trade sparking fears of an imminent wave of overdoses.

Drug and Alcohol Services SA has put out an urgent alert to community advisory groups and healthcare providers after discovery of the drug in used syringes.

UniSa Associate Professor Cobus Gerber. Picture supplied by Dr Gerber

In a South Australian first, accredited researchers collected used syringes and associated paraphernalia such as vials and plastic bags from public disposal bins at three SA Health needle and syringe exchange program sites.

Using sensitive chemical analysis they tested to find what the users had injected, both knowingly and unwittingly.

In a grim discovery the University of South Australia researchers found traces of the deadly drug class nitazene in 5 per cent of the 300 samples.

Nitazenes led to 32 overdose deaths in Australia between 2020 and 2024, while just 16 per cent of patients taken to hospital with overdoses knew the synthetic opioid was present in their drugs.

Lead researcher UniSA Associate Professor Cobus Gerber warned it is increasingly hidden in illicit drugs such as fentanyl and heroin, posing extreme overdose risks.

“Nitazenes are among the most potent synthetic opioids in circulation today, some stronger than fentanyl, which is 50 times more potent than heroin,” he said.

“These substances can be lethal in tiny quantities and are often mixed with other drugs, making them incredibly difficult to detect and monitor through traditional means. It means users are playing Russian roulette, unaware of their risk of overdose.”

Nitazenes were developed by the pharmaceuticals industry in the 1950s but shelved due to their incredible potency and toxic side effects, but recently surfaced in the US then in Australia.

A synthetic opioid 1000 times more potent than morphine is infiltrating Adelaide’s street drug trade sparking fears of an imminent wave of overdoses. Pictured: Danielle Dam.

“They have now been discovered by people using them for the illicit market,” Dr Gerber said.

While it is unknown yet who is adding the drugs or why, Dr Gerber speculated it is a criminal business decision.

“The drug market is a business and people are trying to show their product is more effective, with enhanced effect,” he said.

“Also, people importing heroin have to import a lot but if it is laced with nitazenes they need a much smaller amount for a similar effect — but dealers need to work out how much to use because they don’t want to kill their best customers.

“We are facing a wave of overdoses from people unaware of what they are taking.”

He noted the antidote naloxone is available for free, without prescription, from pharmacies.

Study co-author UniSA researcher Dr Emma Keller said accidental death is a major risk.

“When drugs are contaminated with nitazenes, the margin for error narrows dramatically,” she said.

The detection of these substances comes amid calls for expanded drug-checking services, including the use of nitazene-specific drug strips and public health alerts.

The tests identified several different nitazenes and also the non-opioid veterinary

sedative xylazine, which is not approved for human use.

Dr Gerber warned xylazine has been linked to severe adverse effects, including necrotic skin lesions, prolonged sedation and depression.

The research findings have been published in the Drug & Alcohol Review.

Originally published as A synthetic opioid 1000 times more potent than morphine sparks ‘wave of overdoses’ fears for SA