Iso, a highly addictive opioid more potent than fentanyl, has officially hit the streets.
Just when the focus had shifted to the dangerously powerful synthetic opioid, fentanyl, another even riskier opioid began infiltrating the market.
“Isotonitazene, commonly referred to as ‘iso,’ is causing around 40 to 50 overdose deaths a month in the United States, compared with about six per month last summer,” said Dr. Antonio De Filippo, an addiction specialist and medical director at Delphi Behavioral Health Group. “The numbers are going up as it becomes more popular and widespread.”
Iso is also a synthetic opioid. It is a version of etonitazene, introduced more than half a century ago in 1957 but not approved for medical use because it is highly addictive. In fact, iso, which comes in a yellow or off-white powder, is more powerful than fentanyl.
“Iso appears to be slightly more potent than fentanyl, which itself is as much as 100 times more powerful than morphine,” according to an analysis of the drug published in 2019 in the journal Drug Testing and Analysis.
“The emergence of this novel synthetic opioid is a major public health concern,” said Dr. Robert Glatter, an emergency physician with Lenox Hill Hospital in New York City. “The fact that it has similar potency to fentanyl makes it ripe for abuse and misuse, leading to respiratory depression, along with increased risk for death.”
Etonitazene is a controlled substance but iso remains federally legal “because its chemical structure differs slightly,” said Pat Aussem, director of clinical content and development at the Center on Addiction in New York City. “From a purchasing standpoint, a lot of it is being sold online legally by Chinese suppliers offering bulk deals. The U.S. challenged China to crack down on fentanyl. Chemists there are looking for other ways to fill the demand.”
With fentanyl overdoses already a huge problem, states have decided to take measures to curtail misuse. Ohio, for example, recently announced it would be adding the drug to its list of Controlled Schedule 1 substances. Yet, It has yet to take measures to stop the flow of iso. “Iso was first reported in August 2019 based on analysis of seized drugs in Europe and Canada,” the Ohio Board of Pharmacy said.
Canadian police also seized 1,900 pills in March that was confirmed to be iso in lab tests.
Of the number of fatal overdoses reported, Aussem said, “My suspicion is because it’s not on the radar of many people doing toxicology reports, the more it becomes on their radar we’ll see those numbers increase.”
Another issue is that iso might remain undetected on strips commonly used on the streets to test for the presence of fentanyl. This means users may believe they are ‘in the clear’ when a test comes back negative, only to ingest a highly dangerous concoction.
“Users think they’re doing the safe thing by testing the substances they’re getting, but it may not show up,” Aussem said, adding, “A single dose of naloxone may not do the job, so that’s another risk factor.” Unfortunately, he warned, “It’s always going to be something else. We can keep trying to go after these different variants of opioids, but at the end of the day we just need a comprehensive strategy.”