Knox County forensic center seeks restrictions on cychlorphine after 41 overdose deaths
Knox County officials are seeking restrictions on cychlorphine after the synthetic opioid was detected in 41 overdose deaths in and around Knox County. The drug is described as extremely potent, not detectable through most test kits, and may require repeated naloxone doses in an overdose.
N-Propionitrile Chlorphine, or cychlorphine, has been detected in 41 overdose deaths in and around Knox County, and the Knox County Regional Forensic Center is hoping to get the drug scheduled, or restricted. The forensic center said the synthetic opioid is extremely potent, deadly and spreading fast, and that it is not detectable through most test kits.
The forensic center said it was one of the first to discover the drug in Tennessee, and that cychlorphine has been detected in the area since mid-2025. The very first case was not identified until several months later, after investigators reviewed a death in which law enforcement said the person was supposed to be taking heroin, but there was no heroin in the system and nothing came up with the toxicology. A second look by a research lab found chlorphine.
Right now, a full toxicology evaluation is the only way to detect cychlorphine, and only some partner labs have the resources to confirm it. The forensic center said the primary person using this particular drug does not know that they are taking it, and that the person who sold them the drug is not aware of this being mixed in with a particular drug they are using.
Of the 41 people in East Tennessee who have died from this drug, most were around 42 years old, though recent cases have included people in their early 20s. The forensic center said cychlorphine is 10 times stronger than fentanyl and is mixed in with other street drugs, and it could have been circulating far earlier than the first case detected in July.
The Tennessee Department of Health issued a public warning about cychlorphine last month, saying naloxone is believed to be effective against the drug. Because of the strength of the synthetic opioid, a person experiencing a cychlorphine-related overdose may need repeated doses of naloxone.
The forensic center said it saw a significant decrease in overdoses for xylazine after it was classified as a Schedule III controlled substance in Tennessee, which is similar to what officials are pushing for now with cychlorphine. The center is also waiting for confirmation on two more cases from Tuesday that may be linked to cyclorphine.