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Updated: Feb 14, 2026

Author Spotlight: An Efficient Methodology to Confidently Differentiate and Characterize Fentanyl Analogs
Published on: November 8, 2024
Expected and actual fentanyl exposure among persons seeking opioid withdrawal management
Shannon R Kenney1, Bradley J Anderson2, Micah T Conti3
1Behavioral Medicine Department, Butler Hospital, Providence, RI 02906, United States; Warren Alpert Medical School of Brown University, Providence, RI 02912, United States.
Objective:
Fentanyl-contaminated opioid supplies have led to rising overdose fatalities in recent years. We compared beliefs, behaviors, and risk perceptions related to fentanyl with actual toxicology reports among people who used opioids.
Method:
Participants (n=231) were patients undergoing short-term inpatient opioid withdrawal management in Fall River, Massachusetts. We compared persons testing positive and negative for fentanyl on urine toxicological testing at program entry.
Results:
Nearly all (95.7%) participants believed that fentanyl increases risk for overdose/death, and 86.6% of participants tested positive for fentanyl. Positive fentanyl toxicology test results were associated with lower educational attainment, history of injection drug use, and self-reported lifetime use of fentanyl. Of those reporting they had never been exposed to fentanyl (intentionally or unintentionally) (n=33), two-thirds tested positive for fentanyl; among those believing their tests would be negative (n=49), 71.4% tested positive for fentanyl. Heroin use was associated with fentanyl exposure; persons who reported past month heroin use (n=213) were more likely to test positive for fentanyl (91.1%) than persons using non-heroin opioids (n=18; 33.3%).
Conclusions:
Nearly nine in ten participants tested positive for fentanyl, including participants who anticipated their tests would be negative. Leveraging toxicology results in opioid withdrawal settings may be helpful in educating patients about fentanyl exposure and risks.
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