New ToxIC Publication: An Emerging Synthetic Opioid in the Drug Supply: A Case of Opioid Overdose with Biological Confirmation of Cychlorphine

An Emerging Synthetic Opioid in the Drug Supply: A Case of Opioid Overdose with Biological Confirmation of Cychlorphine

Rebecca Kusko, David Liss, Stacey L. House, Serena B. House, Alex Krotulski, Kim Aldy,
On behalf of the Toxicology Investigators Consortium (ToxIC) Fentalog Study Group

Abstract

Introduction Cychlorphine (also referred to as N-propionitrile chlorphine) is a non-fentanyl synthetic opioid that has been
linked to the illicit drug supply and fatal overdoses in the United States since 2024.
Case Report A female in her 20s presented to the emergency department (ED) following ingestion of what the patient
reported was alprazolam. Unresponsiveness and respiratory depression prompted 6 mg of intranasal naloxone administration
by emergency medical services prior to arrival to the ED. Comprehensive toxicological testing of serum revealed the presence
of cychlorphine. Additional substances found were bromazolam, carboxy-THC, acetaminophen, caffeine, citalopram,
cotinine, naloxone, naproxen, nicotine, and trazodone and its metabolite.
Discussion This rare case of clinical signs of opioid overdose with cychlorphine detected is the first to provide direct evidence
linking a non-fatal overdose to cychlorphine exposure. A naloxone responsive opioid toxidrome is described with an
opiate and fentanyl negative initial urine drug screen. Advanced analytical techniques were required to identify the presence
of cychlorphine.