Fentanyl exposure and preferences among individuals starting treatment for opioid use disorder

Background: Fentanyl has become widespread in the illicit opioid supply, and is a major driver of overdose mortality. Methods: This study used a medical records review at a community opioid use disorder treatment program to examine patient-level correlates of fentanyl exposure as measured by urine testing at admission (N= 1,174). Additionally, an anonymous survey was conducted with 114 patients about their experiences and preferences regarding fentanyl. Results: Overall, 39% of patients entering treatment tested positive for fentanyl. Prevalence of fentanyl exposure differed based on other drug test results (fentanyl-positive = 81.1% vs. 15.4% among participants positive vs. negative for heroin/opioids, p <.001; 59.0% vs. 38.3% among participants positive vs. negative for methadone, p =.001; 53.8% vs. 24.9% among participants positive vs. negative for cocaine, p < .001), prior addiction treatment (40.6% vs. 32.0% among participants with vs. without prior treatment, p < .05), and mental health (36.7% vs. 43.1% among participants with vs. without co-occurring psychiatric diagnosis, p < .05). Most participants reported knowingly using fentanyl (56.1%) and knowing people who prefer fentanyl as a drug of choice (65.8%). Preference for fentanyl (alone or mixed with heroin) was expressed by 44.7% of participants. Participants thought fentanyl withdrawal had faster onset (53.5%), greater severity (74.8%), and longer duration (62.0%) than heroin withdrawal. Conclusions: Recent opioid and cocaine use were strongly associated with fentanyl exposure in this sample. Although fentanyl exposure is often unintentional, there may be a subgroup of individuals who come to prefer fentanyl. Future research should examine the relationship between fentanyl use, patient preferences for fentanyl, and treatment outcomes.