Canberra's drug testing service has detected the highly-potent synthetic opioid fentanyl for the first time, contained in a brown powder sample.
Fentanyl and carfentanil have been found in the ACT before but fentanyl had not been detected in a sample presented for testing before now.
The discovery comes less than three weeks since CanTEST issued a red alert to the community after finding a type of nitazene in a counterfeit Oxycodone pill.
CanTEST's clinical lead Dr David Caldicott said the latest find was of "significant concern".
"We're always anxious about the possibility of fentanyl being present within the drugs market," Dr Caldicott said.
"It's a very potent drug and it's generally not expected by consumers.
"So people who use a product that contains that drug can find themselves in quite a lot of medical difficulty."
The brown powder presented for testing was found to contain paracetamol, caffeine, heroin, 6-MAM and fentanyl.
Dr Caldicott said the person who brought in the sample was "unaware" it contained fentanyl.
"The sample was surrendered because of that apprehension," he said.
David Caldicott says the CanTEST find has been flagged with emergency services so they could be better prepared for potential overdoses. (ABC News: Donal Sheil)
Dr Caldicott warned that the colour of the drug was "coincidental" and he stressed the importance of testing.
"It could be any colour whatsoever," he said.
"You can infer nothing from the colour or appearance of that which is supplied to us."
'50 times stronger than heroin'
Fentanyl is up to 50 times stronger than heroin and around 100 times more potent than morphine.
The synthetic opioid can cause a fatal overdose, with overdose signs including loss of consciousness, pinpoint pupils, discoloured lips and nails, cold or clammy skin, and choking, coughing, gurgling or snoring sounds.
The medicine naloxone can rapidly reverse the effects of an opioid overdose or adverse reaction, and is widely available for free with no prescription through pharmacies and harm reduction services across the country.
Suzanne Nielsen says fentanyl is a very concerning, fast-acting drug. (ABC RN: Jeremy Story Carter)
Monash Addiction Research Centre deputy director Suzanne Nielsen said with a fentanyl overdose there was only a very short window, as little as two minutes, to intervene, compared to around 25 minutes for heroin.
"It's a very potent drug but it's also a fast-acting drug," Professor Nielsen said.
"The combination of both of those things is why we're very concerned about fentanyl."
Naloxone is free under the Take Home Naloxone program and is available from approved providers such as hospital pharmacists, community pharmacies, or alcohol and other drug treatment centres. (ABC News: Curtis Rodda)
A reduction in global heroin production, Professor Nielsen said, was seeing more of the heroin supply contaminated with synthetic opioids that were cheaper to make and easier to ship.
"It is likely that with less heroin around we will start to see these much more potent opioids sold with heroin," she said.
'We don't want fentanyl to get a hold'
The fentanyl finding has been flagged with emergency services, Dr Caldicott said, so they could be better prepared for potential overdoses.
"Knowing that it's out there means we can give messages to healthcare providers and to ambulance services and they can be on their guard, and be aware that they may have to provide an alternative form of resuscitation than they had anticipated," he said.
"Without these sorts of drug checking services … this probably would have gone unnoticed until such point as a patient, or several patients, arrived at an emergency department, or even worse."
ACT Policing said it had "not identified a significant increase in overdose matters" since issuing a public health warning in August, and that those overdoses were still under investigation.
The United States is in the grip of a fentanyl crisis where an estimated 74,702 people died from the drug in 2023. (Reuters: Shannon Stapleton)
Dr Caldicott said Australia's healthcare system and widespread availability of naloxone meant the country had so far avoided the fentanyl crisis currently gripping the United States.
"We don't want to allow fentanyl to get a hold within the Australian market," he said.
Professor Nielsen said the introduction of potent opioids into the United States drug market had seen an "almost exponential increase" in deaths and fentanyl becoming a predominant drug.
"We have been watching this unfold overseas in the US and we're very concerned about these kinds of detections starting in Australia," she said.
"So, this recent detection does make us think that we are at risk of being in a similar situation."