Impact of Fentanyl Use on Buprenorphine Treatment Retention and Opioid Abstinence

Objectives: There has been a rapid increase in the presence of illicitly manufactured fentanyl in the heroin drug supply. Buprenorphine is an effective treatment for heroin and prescription opioid use disorder; however, little is known about treatment outcomes among people using fentanyl. We compared 6-month treatment retention and opioid abstinence among people initiating buprenorphine treatment who had toxicology positive for heroin compared to fentanyl at baseline. Methods: Retrospective cohort study of 251 adult patients initiating office-based buprenorphine treatment who had available toxicology testing across an academic health system between August 2016 and July 2017. Exposure was assessed at baseline before initiating buprenorphine and was categorized as negative toxicology (n = 184) versus fentanyl positive toxicology (n = 48) versus heroin positive toxicology (n = 19). Results: Six-month treatment retention rates were not different between the fentanyl positive and heroin positive groups [38% (n = 18) vs 47% (n = 9); P = 0.58], or between the fentanyl positive and the negative toxicology group [38% (n = 18) vs 51% (n = 93); P = 0.14]. Opioid abstinence at 6 months among those who had testing did not differ between the fentanyl positive and the heroin positive group [55% (n = 6) vs 60% (n = 6); P = 0.99]. The fentanyl positive group had a lower abstinence rate at 6 months compared to those with negative toxicology at baseline [55% (n = 6) vs 93% (n = 63); P = 0.004]. Mean initial buprenophine dosage did not differ between groups. Conclusions: Buprenorphine treatment retention and abstinence among those retained in treatment is not worse between people using fentanyl compared to heroin at treatment initiation. Both groups have lower abstinence rates at 6 months compared to individuals with negative toxicology at baseline. These findings suggest that people exposed to fentanyl still benefit from buprenorphine treatment.