Illicit Opioid Adulterant Trends in Patients Presenting with Acute Opioid Overdose.
Publication/Presentation Date
2-19-2026
Abstract
BACKGROUND: Clandestine fentanyl manufacturing oftentimes introduces adulterants and contaminants. This paper aims to evaluate trends in adulterants from a cohort of patients presenting to the emergency department (ED) with illicit opioid overdose across the United States.
METHODS: The Fentalog Study group is a multicenter toxicology study group which evaluated ED patients with suspected opioid overdose at 10 medical centers across the United States between September 21, 2020 through February 5, 2024. Comprehensive qualitative toxicology testing was performed on residual serum specimens. Study sites were divided into three geographic regions: West (California, Oregon, Colorado), Midwest (Missouri, Michigan), and East (New York, New Jersey, Pennsylvania, Georgia). Illicit opioids were defined as fentanyl and fentanyl analogs, heroin or its metabolites, and/or novel potent opioids such as nitazenes.
RESULTS: 1295 patients with confirmed illicit opioid overdose were included. Males accounted for the majority (73.7%) of patients. The median age was 39 (IQR: 31-54) years. Adulterants were detected in 745 (57.5%) patients. Quinine was the most abundantly encountered adulterant (433; 33.4%). Antihistamines were the most frequently detected class of adulterants (19.6%). There were significant differences in adulterants detected across the three time periods, with notable decreases in adulterants from time-period 1 (79.5%) to time-period 3 (41.7%; p < 0.001). Adulterants were found in 84 (27.0%) of patients that presented to a hospital in the Western United States, compared with 181 (24.3%) in the Midwest, and 480 (64.4%) of patients in the East (p < 0.001). Patients with concurrent cocaine were more likely having an adulterant present than those without cocaine present (OR 1.23; 95% CI 1.15-1.31). In contrast, patients with illicit opioids and concurrent methamphetamine were less likely to have adulterants present (OR 0.89; 95% CI 0.84-0.95).
CONCLUSIONS: Adulteration of illicit opioids was more likely in the Eastern United States and for those with concurrent cocaine and opioid exposures.
ISSN
1945-2403
Published In/Presented At
Levine, M., Culbreth, R., Buchanan, J., Schwarz, E., Love, J., Brent, J., Meaden, C. W., Judge, B., Aldy, K., Hendrickson, R., Hughes, A., Krotulski, A., Logan, B., Shulman, J., Carpenter, J., Wax, P., Amaducci, A., Calello, D. P., Campleman, S., Manini, A. F., … Toxicology Investigators Consortium (ToxIC) Fentalog Study Group (2026). Illicit Opioid Adulterant Trends in Patients Presenting with Acute Opioid Overdose. Journal of analytical toxicology, bkag006. Advance online publication. https://doi.org/10.1093/jat/bkag006
Disciplines
Medicine and Health Sciences
PubMedID
41712495
Department(s)
Department of Emergency Medicine, Department of Emergency Medicine Faculty, Toxicology Division
Document Type
Article