A ‘Frankenstein’ opioid estimated to be up to 40 times more powerful than fentanyl is now sweeping Britain, experts warn.

Nitazenes are made in clandestine Chinese laboratories and smuggled into Britain through the usual criminal channels.

The synthetic drug – mixed into heroin by money-hungry dealers because it is cheap, addictive and enhances the euphoric effect – is accused of causing an “unusual” increase in overdoses and deaths in recent months.

In addition to being mixed into other substances, it is also sold as oxycodone pills or Xanax powders, according to charities.

Experts told MailOnline that the rise of nitazenes in Britain is ‘very worrying’ as the addictive drugs are now prevalent in most regions.

For most, it is ‘too late’ before they realize they have taken nitasenes.

Nitazenes are made in clandestine Chinese laboratories and smuggled into Britain through the usual criminal channels. According to data from the UK Advisory Council on the Misuse of Drugs, in 2021 alone, two dozen deaths were linked to isotonitazene, a form of nitazene.

Nitazenes were originally developed as painkillers by the Swiss pharmaceutical company Ciba in the 1950s, but never came to market.

However, in recent years they have emerged among drug users in the US, earning the nickname ‘Frankenstein’ opioids because they are so powerful.

It is believed to have formally arrived in Britain about two years ago, when the National Crime Agency first noticed it among overdose patients.

They are available in powder, tablet and liquid form and can be injected, swallowed, placed under the tongue, snorted and vaporized.

The drugs cause feelings of pain relief, euphoria, relaxation and drowsiness. But they can also cause sweating, itching and nausea.

What are nitazenes?

Nitazenes are a synthetic opioid made in clandestine Chinese laboratories.

They are accused of fueling an “unusual” increase in overdoses and deaths in recent months.

They are mixed with heroin and have also been found in heroin oxycodone pills and Xanax powders, according to charities.

Nitazenes were originally developed as painkillers by the Swiss pharmaceutical company Ciba in the 1950s, but never came to market.

They are available in powder, tablet and liquid form and can be injected, swallowed, placed under the tongue, snorted and vaporized.

The drugs cause feelings of pain relief, euphoria, relaxation and drowsiness. But they can also cause sweating, itching and nausea.

Nitazenes mimic the effects of natural opioids – such as morphine – and are often adulterated with these drugs, creating a deadly cocktail.

Users do not always know that they are consuming nitazenes. Police have discovered that some people who thought they were using heroin were actually using nitasenes, paracetamol and caffeine.

According to data from the UK Advisory Council on the Misuse of Drugs, in 2021 alone there were two dozen deaths from isotonitazene, a form of nitazene.

Iso, often called ‘Tony’, is the most common in toxicology reports, experts told MailOnline.

Addition clinics say the nitasenes come from unregulated labs in China.

Experts believe these labs have flooded research papers for early attempts to develop synthetic opioids and have come across nitasenes, which are cheaper to make than fentanyl. Fentanyl itself is favored by dealers because it is so cheap compared to heroin.

The increasing presence of nitasenes in Britain has been attributed to the Taliban restricting the poppy crop in Afghanistan, which supplies the bulk of Britain’s heroin. It has forced criminal gangs to look for alternatives.

In July, the OHID published a national patient safety alert about the drug.

While around 40 opioid deaths are recorded every week in England and Wales, on average there has been an ‘increased number of overdoses’, especially among heroin users, some of which led to death. However, the OHID did not share its data.

According to the OHID, the cases are geographically widespread, with some towns and villages in most regions of Britain affected.

Tests show that nitasenes, which are available for sale on the dark web, are the ‘common cause’ behind the overdoses.

“Their potency and toxicity are uncertain, but perhaps comparable to, or even more than, fentanyl, which is approximately 100x morphine,” the OHID added.

It urged NHS teams, care providers and private and voluntary drug and alcohol services to be aware of the ‘risk and serious toxicity’ of using heroin containing nitasenes and warn drug users.

Nitazenes are available in powder, tablet and liquid form and can be injected, swallowed, placed under the tongue, snorted and vaporized.  In the photo: opioids

Nitazenes are available in powder, tablet and liquid form and can be injected, swallowed, placed under the tongue, snorted and vaporized. In the photo: opioids

Experts believe these labs flooded research papers for early attempts to develop synthetic opioids and came across nitasenes, which are cheaper to make than fentanyl (pictured).  Fentanyl itself is favored by dealers because it is so cheap compared to heroin

Experts believe these labs flooded research papers for early attempts to develop synthetic opioids and came across nitasenes, which are cheaper to make than fentanyl (pictured). Fentanyl itself is favored by dealers because it is so cheap compared to heroin

The OHID noted that naloxone – the antidote for opioid overdoses – works against nitasenes.

But it must be given ‘quickly’ as the drug is more likely to cause respiratory arrest because it is so powerful.

Research shows that patients who take too many nitazenes typically need two doses of naloxone to recover, while fentanyl users only need one.

Nitazenes are a Class A substance, meaning possession can lead to seven years in prison, while supplying them can result in a life sentence. Unlimited fines can also be issued for both violations.

Police have issued warnings about the nitasenes in recent weeks, warning that they are “incredibly dangerous” and can be “deadly” if taken in the same doses as natural opioids.

West Mercia, which covers Herefordshire, Shropshire and Worcestershire, reported that nitasenes are responsible for up to 20 overdoses in the area.

Charities in Birmingham say they have recorded more than 30 overdose deaths in June and July. Twenty-four of these were associated with isotonitazene – three times more than usually expected from individual drugs during the summer months.

Experts have raised concerns that nitazenes could appear in other drugs, such as ketamine and cocaine, as has been observed with fentanyl. This could increase the risk of overdose among a broader group of drug users.

National agencies are working together in the hardest-hit areas, warning drug users of the risks and ensuring more naloxone is available.

Ian Hamilton, associate professor of addiction at the University of York, told MailOnline that the rise in deaths from nitasenes is “very worrying, but not surprising given how powerful they are.”

He said: ‘They have entered circulation over the past year, partly due to reduced supplies of heroin from Afghanistan as the Taliban restricted opium cultivation.

‘Unfortunately, the demand for opiates has not decreased and it appears that these types of drugs are filling the gap.

“Most people will not be aware that they are taking these types of opiates or how strong they are until it is too late and they experience problems, including overdose.”

Professor Colin Davidson, head of pharmacy and biomedical sciences at the University of Central Lancashire, told MailOnline that nitasenes are of ‘very concern’.

He said: ‘Some are more powerful than fentanyl and heroin, two of the most dangerous drugs.’

Studies suggest that these drugs prevent animals from breathing at lower doses than fentanyl, and have a much longer effect.

‘It’s the stopping of breathing that makes these drugs so dangerous. Fortunately, overdoses can be treated with naloxone if given quickly enough,” he added.

A government spokesperson said: ‘Every death resulting from an overdose of illicit drugs is an avoidable tragedy. That is why we are committed to combating the trafficking and use of illegal drugs. We are working with partners to closely monitor this situation, detect and break drug supply chains, warn people who may be at risk and save lives.

‘More broadly, our 10-year drug strategy is boosting drug treatment and investing £532 million in tackling addiction.

‘By the end of parliament, local government treatment funding will have grown by 40 per cent compared to 2020.’