Nitazenes more powerful than fentanyl? What you need to know

“When you look at what is happening to the heroin supply there are just more and more additives.”

by Katharin Czink and Dina Bair | Feb. 14, 2024

Story at a glance

Nitazenes are a class of opioids now found in pills and powder sold on the street.

They are 20 times more powerful than fentanyl and may take much more Narcan to reverse an overdose.

Nitazenes date back to the 1950s but have never been legally produced because they are so potent.

(WGN) — Fentanyl is largely fueling the deadliest overdose crisis in U.S. history, but nitazenes are 20 times more powerful.

Nitazenes are a class of opioids now found in pills and powder sold on the street. And while Narcan can help reverse an overdose, it may take much more.

Nitazenes date back to the 1950s when academic chemists were looking for ways to create opiates without using the poppy plant.

“They figured out that a nitazene does attach to an opioid receptor, but they actually didn’t like how potent it was, so no one ever brought it to market,” said Jenna Nikolaides, a toxicologist and emergency and addiction medicine physician with Rush Hospital.

Still, the formula is available in the medical literature, and now it’s in the hands of drug dealers.

“The fact that metonitazene is in the drug means that they are using very, very contaminated drugs,” Nikolaides said.

Nikolaides is just starting to see the drug in circulation – confirmed by advanced testing – known to be 20 times more powerful than fentanyl.

“When you look at what is happening to the heroin supply there are just more and more additives,” she said.

Nikolaides said the new additive does not show up on standard urine screens or on the harm reduction test strips she distributes to drug users hoping to reduce their risk for the more dangerous additives infused into street drugs.

“You test a sample bag of heroin and it has maybe a little bit of heroin, a little bit of fentanyl, a little bit of metonitazene, a little bit of cocaine, a little bit of sedatives, a little bit of crushed pharmaceuticals,” she said. “So sometimes quinidine is in there, Benadryl is in there. If nitazene is in there, it’s a garbage bag of drugs.”

Like heroin and morphine, nitazenes attach to receptors in the brain and cause depression of the central nervous system. In the case of an overdose, the respiratory system slows to dangerous levels. The signs are clear — you can’t wake the person up; they have pinpoint pupils; slow or non-existent respirations, and a low heart rate. But what’s not clear is how many doses of Narcan it will take to reverse an overdose if nitazene is present.

Anthony March, a Northwestern Medicine addiction medicine specialist, has been treating patients addicted to drugs since the 1980s.

“If you’re going to use a drug, it may be one time and you’re out. You may not even be addicted. It could be some kid whose friend said, ‘Hey, try this.’ One and done. It’s really terrible,” he said.

He worries users won’t get enough Narcan if bystanders don’t see results after the typical one to two doses — either by nasal spray or injection — it takes to reverse a typical overdose.

“That’s a real problematic decision point. And if it is still the narcotic and you back off too soon on the Narcan, they could die,” March said. “Don’t be afraid to give up to four vials or five vials, and if they start waking up, you are on the right path. This is an opiate.”

But there’s another worry. Even first-time users are at risk.

“I’m detecting nitazene opioids in the opioid-using patients that are having a harder time quitting, so I think the nitazene opioids also deepen addiction,” March said. “But if you mix up the bag or you get the wrong bag, and your tolerance isn’t that high and you get the nitazene bag, then maybe you overdose and die.”

Yet another drug has the potential to be even more deadly. Xylazine, an animal tranquilizer, is also being added to street drugs. It is not an opioid, therefore Nalaxone or Narcan may not be effective to reverse an overdose depending on the xylazine concentration in the drug cocktail and what else is in the mix.