In 2019, a new group of drugs began taking lives in Europe and North America – nitazenes. They are designed to have similar effects in the brain to morphine and heroin, and belong to the group new synthetic opioids. But nitazenes can be several hundred times stronger than heroin.
When nitazenes were first used as drugs of abuse, they had already existed for about 60 years. They were developed by pharmaceutical companies seeking to develop new pain medications similar to fentanyl. But nitazenes were found to have unacceptable side effects that put an end to their potential as a drug.
“More potent than fentanyl”
“There are nitazenes more potent than fentanyl, which is the most powerful opioid we use in healthcare. Even very small doses can give large effects and, above all, side effects. If you take too much, the breathing centre in the brain can shut down and you die from respiratory arrest,” says Henrik Green, professor of forensic sciences at Linköping University.
There are several examples of nitazenes having been sold in false packaging, or mixed in with other substances, so that those who take the substance do not know what they are actually taking. There is a very high risk of fatal overdose. In 2024 alone, 31 people in Sweden died of nitazenes, according to the National Board of Forensic Medicine. Half of them were younger than 35.
In the autumn of 2024, the Swedish Police Authority and the National Board of Forensic Medicine issued a sharp warning about nitazenes. The Police closed down sites that sold them openly.
Behind-the-scenes research
The public agencies’ efforts against the trade in nitazenes were preceded by behind-the-scenes research. This is where Henrik Green’s research team comes into the picture. In order for law enforcement agencies such as police and prosecutors to be able to take action against a new psychoactive substance, it must be first classified as narcotics. This means that the manufacturer only has to replace one single atom compared to a drug-classified substance for the molecule to be considered a new preparation that is not illegal to sell and possess.
“We work together with the Public Health Agency of Sweden to classify the nitazenes. This work led to the National Board of Forensic Medicine and the Swedish Police Authority being able to shut down websites, which substantially reduced distribution,” says Henrik Green.
After this operation, the number of deaths linked to nitazenes has dropped.
The fact that new online drugs are legal for a period of time, and also easy to get hold of through websites that sell them, makes some people think they are harmless.
“Hopefully, we will help people become aware that these types of drugs are an extremely bad choice. When they arrive, we have no idea how strong they are or what side effects they have. So the preventive work feels important – visiting in schools to talk about this and cooperating with the authorities so that they can reach out to the public with correct information,” says Henrik Green.
Speeds up legislation process
His research group has developed new methods and processes to forward important information about new online drugs as quickly as possible to national public health authorities and the European Union Drugs Agency, EUDA. The researchers find out how the substance acts in the body and how strong its effect is. They can also get indications of which substances are the most addictive. Their reports are sent directly to the authorities. This speeds up the process considerably, compared to previously, when public agencies had to wait for researchers to share their results in scientific publications.
The approach has had a positive effect on efforts to investigate and regulate new substances. In one project, the LiU researchers are subcontractors to the National Board of Forensic Medicine, which provides data to the Public Health Agency of Sweden. For the first five years, data from the project was included in about 50 classification cases concerning narcotic drugs. In half of the cases, the research group’s data was the only available scientific evidence.
The research group’s data can help investigators at the Public Health Agency of Sweden prioritise among emerging substances. In this way, resources can be directed toward substances that are particularly important to investigate and regulate, for example substances widely distributed in Sweden.
“A large proportion of the data from the project concerns opioids, the investigation of which is extra prioritised because they involve a high risk of ill health and death. Another group is the cannabinoids, where new substances are emerging at a rapid pace,” says Åsa Bertilsson Pfuhl, investigator at the Public Health Agency of Sweden.
Potential to do good
Several of the substances that some use as drugs were actually originally developed for medicinal use. The opposite can also happen. Henrik Green explains that among the new psychoactive substances there may be substances with potential to be used in health care:
“We always keep track of substances that could potentially have medical use. We can study such substances in other types of studies to see if they can be developed in a different direction.”