Research from the Centres for Disease Control and Prevention this week suggests that two recently resurfaced drugs are now contributing to the ongoing overdose crisis in the U.S. Among both reported overdose deaths and drug busts, officials are seeing an increase of the drugs para-fluorofentanyl and metonitazene, either in combination with fentanyl or taken alone. The drugs are believed to be more potent than fentanyl, but overdoses can still be reversed with the medicine naloxone.
The report, published Thursday in the CDC’s Morbidity and Mortality Weekly Report, is based on national data collected from law enforcement seizures as well as toxicology data from the Knox County Regional Forensic Centre (KCRFC) in Tennessee, which handles many of the state’s autopsies.
In November 2020, Tennessee coroners began to see overdoses that involved the drug para-fluorofentanyl; in January 2021, they began to see metonitazene pop up. From 2020 to early 2021, these drugs also started to increasingly appear in seizures. While the drugs have usually been found with fentanyl or each other, reports of people dying from either alone have started to increase over time as well. Out of 562 overdose deaths that tested positive for fentanyl reported by the KCRFC from November 2020 to August 2021, 48 also involved para-fluorofentanyl and 26 involved metonitazene. Other states have reported the emergence of these and other novel drugs on the market in recent years as well.
Para-fluorofentanyl is a fentanyl analogue first developed in the 1960s that saw some popularity in the black market up through the 1980s, before it was classified as a Schedule 1 drug by the federal government. Metonitazene belongs to a class of synthetic drugs known as benzimidazole-opioids. These drugs were first synthesized in the 1950s but have never seen clinical use due to concerns about their health risks. Para-fluorofentanyl and metonitazene are thought to be snorted or injected, and both seem more likely to cause life-threatening overdoses than even fentanyl, which is already a more potent opioid than heroin, according to report author Darinka Mileusnic-Polchan, head of the medical examiner’s office in Knoxville, Tennessee.
“These [victims] just crumple and collapse. Frequently they don’t even inject the full syringe” before overdosing, Mileusnic-Polchan told the AP.
Because both drugs have opioid properties and/or are taken with fentanyl, naloxone can still reverse potentially fatal overdose symptoms like respiratory depression (the slowing or stopping of breathing). But the CDC report authors expressed concern that it will take higher or repeated doses of naloxone to rescue these victims. And the combination of these drugs with fentanyl or other drugs is likely to “pose an even greater potential harm to the patient than that previously observed,” the report authors say.
Overall, the overdose crisis has continued to worsen. In 2020, it’s estimated that more than 100,000 Americans died from an overdose, which often involved a combination of fentanyl and other drugs. This increase has happened despite successful efforts to limit the prescribing of legal opioids to patients, which has led many experts and patient advocates to question the effectiveness of these policies. Many organisations have instead called for a greater use of harm reduction methods, such as increased access to medication assisted treatments and safe injection/consumption sites. In New York City, where the country’s first legal sites opened late last November, dozens of overdoses have already been reversed.