CDC

Surge in overdoses traced to medetomidine-opioid mix in Chicago

May 6, 2025

According to a recent CDC report, twelve confirmed and 26 probable cases of medetomidine-involved overdose occurred in Chicago, Illinois, during May 11–17, 2024, mostly among non-Hispanic Black or African American men aged 45 to 64 years. Bradycardia and lack of response to naloxone were defining clinical features. Fentanyl was present in all blood specimens and drug samples that tested positive for medetomidine.

Multisector surveillance is needed to quickly identify and respond to new adulterants introduced into the illegal drug supply. Clinicians who observe atypical toxidromes associated with suspected opioid-involved overdoses should contact their local health department and continue to provide naloxone and linkage to evidence-based treatment.

Source:

Nham A, et al. (2025, May 1). CDC. Overdoses Involving Medetomidine Mixed with Opioids — Chicago, Illinois, May 2024. https://www.cdc.gov/mmwr/volumes/74/wr/mm7415a1.htm