We’ve detected a potent opioid in Canberra. Here’s what we know about it

Australia’s first government-sanctioned drug-checking service CanTEST has issued its inaugural ‘red alert’, the highest level of warning, following the detection of metonitazene in a yellow pill masquerading as the pharmaceutical drug oxycodone. We should be very worried about this drug’s emergence in Australia.

Metonitazene is part of the nitazene family of drugs, also known by the less snappy name ‘2-benzylbenzimidazole’. Originally developed in the 1950s by the pharmaceutical company CIBA, they have never been marketed for medical or veterinary use. They are synthetic opioids that are considerably more potent than morphine.

Metonitazene itself is estimated to be between 30 and 200 times the potency of morphine. As such, nitazenes are of toxicological concern in the same way the illicit fentanyl family is – they have a track record of causing death from respiratory failure.

The potential for misusing nitazenes was flagged by the godfather of MDMA himself, Alexander Shulgin, as early as 1975. They sporadically cropped up in overdose case reports prior to 2000, but in recent years have begun to intrude on the illicit fentanyl market in the United States and Europe.

Historically we have been spared the impact of nitazenes in Australia, but there has been recent evidence of growing interest in their use. Both New South Wales and Victoria have released warnings regarding the presence of nitazenes on the market in the past year, as has New Zealand last October.

The true extent of the spread of nitazenes in Australia and New Zealand is probably underestimated, as analysis has not routinely been conducted on this drug group. Test strips exist for the fentanyl family of drugs, but they will not detect nitazenes. That requires the expertise, intuition and sophisticated equipment of qualified analytical chemists, such as those working with CanTEST and Pill Testing Australia in Canberra.

The detection from the ACT is associated with a purported clandestine pharmaceutical oxycodone, in pill form. There is a significant market in genuine but diverted pharmaceutical opioids, which perhaps gives consumers a false sense of ‘quality’ or ‘safety’.

While even genuine pharmaceutical opioids can be associated with harm when misused by those for whom they are prescribed, the use of opioids claimed to be diverted from legitimate sources is more dangerous still.

Clandestinely acquired, purported pharmaceutical opioids have none of the rigorous quality assurance of a medical supply, and as a consequence can contain dangerous products, particularly if used unawares. It was the combination of a dangerous product, misrepresented as a medicine, which elevated this analysis to the recommendation of a red alert.

Unlike many of the other detections reported in Australia, the recent detection of metonitazene in Canberra was not predicated upon the overdose of a young consumer. The whole point of drug-checking or ‘pill testing’ is to prevent such tragedies and provide an evidence-based alternative to the potential consumer, as happened here.

In this case, the substance tested was found not to contain the claimed oxycodone. The patron who supplied the pill discarded it and will return to their community a little wiser for their experience, and certainly much safer for avoiding the potential harms of the substance. They will also be able to pass on the details of their encounter to inform peers.

At the same time, the team at CanTEST has obtained invaluable intelligence about the drugs market to be shared with colleagues across the country. The prevention of overdoses is a far more desirable outcome for public health than the mere annotation of their frequency.

Fortunately, nitazenes do respond to naloxone – a drug that can temporarily reverse opioid overdose. With reasonable community access to this life-saving intervention, in Australia we are to a degree protected from the possibility of multiple fatalities like those being seen overseas.

Why are nitazenes emerging now? With recognition of the harms being caused by fentanyls across the US, wide-ranging prohibitions of ‘fentanyl core structure’ compounds have occurred. Nitazenes do not share those core structure elements with fentanyls, initially exempting them from the same laws.

However, legislation has caught up with nitazenes and they are now illegal in most jurisdictions. More broadly, this family of drugs appears to be adhering to the ‘iron law of prohibition’, where the harder the law enforcement becomes, the harder or more potent the drugs become.

In the ACT, we are in a stronger position this year to identify novel drugs that pose a threat to the public, while the implications from the prosecution of the war on drugs is discussed further afield.