biostudies-literatureAzar PHealth Canada Substance Use and Addictions Program58https://www.ebi.ac.uk/biostudies/studies/S-EPMC12306136biostudies-literatureUnknown20(1)<h4>Background</h4>Most opioid use disorder (OUD) treatment guidelines target community medical settings, and the subsequent recommendations were established to prioritize safety and reduce diversion prior to the fentanyl era. For people with OUD who use unregulated fentanyl, slow induction onto opioid agonist therapy (OAT) with gradual dose titration is often ineffective or insufficient for reducing withdrawal symptoms and cravings, thereby hampering engagement and retention in treatment. Given the severe risks associated with continued use of the increasingly toxic unregulated drug supply, new and innovative approaches to the management of OUD are urgently needed. We have developed an alternative induction protocol, using a rapid intravenous symptom-inhibiting fentanyl induction (SIFI) tAddiction science & clinical practiceRapid intravenous symptom-inhibiting fentanyl induction (SIFI) to optimize rotation onto oral opioid agonist therapy among individuals who use unregulated fentanyl: protocol for an open-label, single arm clinical trial.PMC123061362021-HQ-000060Davison RHarris MBarrios RMaharaj ABarazanci ZIgnaszewski MJForeman JGuillemi SAAzar PMontaner JSGWong JSHMathew NHall DfalseRapid intravenous symptom-inhibiting fentanyl induction (SIFI) to optimize rotation onto oral opioid agonist therapy among individuals who use unregulated fentanyl: protocol for an open-label, single arm clinical trial.<h4>Background</h4>Most opioid use disorder (OUD) treatment guidelines target community medical settings, and the subsequent recommendations were established to prioritize safety and reduce diversion prior to the fentanyl era. For people with OUD who use unregulated fentanyl, slow induction onto opioid agonist therapy (OAT) with gradual dose titration is often ineffective or insufficient for reducing withdrawal symptoms and cravings, thereby hampering engagement and retention in treatment. Given the severe risks associated with continued use of the increasingly toxic unregulated drug supply, new and innovative approaches to the management of OUD are urgently needed. We have developed an alternative induction protocol, using a rapid intravenous symptom-inhibiting fentanyl induction (SIFI) t2025-01-01T00:00:00Z2025 Jul2026-07-15T12:33:50.166Z2025-08-27T03:11:20.927ZS-EPMC123061364073102410.1186/s13722-025-00586-7