Fentanyl overdose history and cocaine use severity are associated with how people mitigate risks of fentanyl-adulterated cocaine.

Introduction: Despite rising concern about overdoses from fentanyl-adulterated cocaine, research on responses to adulteration among people who use cocaine (PWUC) is limited. We aimed to identify what risk mitigation strategies PWUC would engage in if they suspected fentanyl in their cocaine. Secondarily, we tested whether key individual differences were related to use of risk mitigation strategies.

Methods: A secondary analysis of an online study (CTN Protocol ID: CTN-0130) collected responses from 97 self-reported cocaine purchasers. Participants completed questionnaires on demographics and substance use and reported what they would do if they found out their cocaine might contain fentanyl. Participants selected from a list of behaviors (with a free response option). Responses were coded into a four-level variable: “no change,” “transfer risk,” “harm reduction,” and “abstain.”

Results: About 16.5% endorsed no change in their behavior, 14.4% endorsed transfer risk, 25.8% endorsed harm reduction, and 43.3% endorsed abstain. Of the 10 individual differences tested only cocaine use frequency and previous personal experience of overdose significantly related to selected behaviors. Further analysis showed those with more frequent cocaine use, or prior overdose experience were more likely to use cocaine normally or transfer risk rather than use harm reduction or abstain.

Conclusion: While 83.5% of our sample reported they would attempt to mitigate risk if they suspected fentanyl in their cocaine, participants with more frequent cocaine use or a prior overdose endorsed less use of typical harm reduction or abstention. This highlights the need to direct harm reduction interventions to PWUC to mitigate the fentanyl overdose risks.

Related protocols: CTN-0130

Categories: Cocaine, CTN platform/ancillary study, Fentanyl, Overdose
Tags: Article (Peer-Reviewed)
Authors : Anighoro, Benedicta; Nunez, Cecilia; Wardle, Margaret C.
PMID : 42252676
Source : Substance Use & Misuse 2026 (in press). [doi: 10.1080/10826084.2026.2682310]