A new type of opioid is killing people in the US, Europe and Australia

America and Europe Authorities are fighting a new enemy in the war on opioids. Nitazenes are a class of synthetic drugs 40 times more potent than fentanyl that have caused hundreds of confirmed deaths across Europe and the United States since coming on the radar of law enforcement agencies in 2019.

Nitazenes were first synthesized in the 1950s by CIBA Aktiengesellschaft, an Austrian chemical company, which created several chemically related molecules with varying levels of analgesic potency. However, their use as housing never went away. In addition to being addictive, nitazenes can cause respiratory depression, a dangerous condition in which breathing becomes too shallow to replenish oxygen in the blood. So until they appeared on the illegal market, these drugs were largely unheard of for decades.

It’s hard to say exactly how long nitazenes have been routinely sold as street drugs — identifying them requires special tests that aren’t routinely performed — but law enforcement agencies began identifying them about six years ago. A shipment of one type of these synthesized molecules — isotonitazane — was intercepted in the US Midwest in 2019, and deaths began to appear in the US and Europe over the following years.

Pharmacists and dealers were most likely attracted to nitazenes because of their potency and because they have similar effects to more well-known drugs such as heroin. This makes them useful substances for dealers, as they can use them to cut other opioids in order to push their drug further and increase sales volume. This poses serious risks to users, who are often unaware of what they are actually consuming, increasing the risk of overdose.

Another attractive feature of nitazenes was that they were forgotten by the authorities: a drug with less attention and also an uncertain legal status is easier to trade. Illegal laboratories are believed to have begun synthesizing nitazenes using historical chemical formulas found in pharmacology textbooks as well as developing new formulas.

In the United States, nitazenes are now widespread in most parts of the country and are produced in Mexico or domestically in illegal laboratories supplied with raw materials by Asian vendors. Synthetic opioids are the most problematic drug in the United States—accounting for nearly 70 percent of the 105,000 overdose deaths recorded in 2023—and of these, fentanyl is the most common. But nitazenes, while still a minority drug, are rapidly becoming more common.

Europe, for its part, has always been a market dominated by heroin, and almost all of it comes from Afghanistan. However, when the Taliban regained power in Afghanistan in 2021, they banned poppy cultivation, thus cutting off the source of the raw material used to produce heroin destined for Europe. As opium supplies run out, it is possible that there will be a shortage of heroin on the European market that synthetic opioids can fill.