Emergency Department–Initiated Buprenorphine for Opioid Use Disorder

Importance: Extended-release injectable buprenorphine may expand the reach of initiating medications for opioid use disorder in high-risk and hard-to-reach individuals who visit the emergency department (ED) and can be administered in low levels of withdrawal. Objective: To compare the effect of ED-initiated 7-day extended-release injectable buprenorphine vs sublingual buprenorphine on treatment engagement at 7 days. Design, Setting, and Participants: Multicenter randomized clinical trial enrolling adult patients presenting to the ED with untreated opioid use disorder and a Clinical Opiate Withdrawal Scale (COWS) score of 4 or higher across 29 EDs in the US from July 12, 2020, to August 21, 2024. Final follow-up was completed on October 24, 2024. Interventions: Patients were randomized to receive a 24-mg injection of extended-release buprenorphine (equivalent to 16 mg/d) or sublingual buprenorphine, which included either self-administration instructions if the COWS score was less than 8 or administration of 8 mg of sublingual buprenorphine in the ED if the COWS score was 8 or higher. All sublingual buprenorphine group patients received a 7-day prescription for 16 mg/d. Both groups were provided referral for ongoing medication with a scheduled appointment within 7 days. Main Outcomes and Measures: Engagement in opioid use disorder treatment on day 7 was the primary outcome. Secondary outcomes included engagement at 30 days, precipitated withdrawal and overdose events, craving scores, days of illicit opioid use, and patient satisfaction with treatment. Results: Among 2000 patients randomized, 6 who were enrolled twice were excluded, resulting in 991 in the extended-release group and 1003 in the sublingual group. The median age was 37 (IQR, 30-47) years, 68% were male, 31% had an initial COWS score of 4 to 7, and 76% tested positive for fentanyl. The adjusted proportion of engagement in opioid use disorder treatment at 7 days was 40.5% with extended-release buprenorphine vs 38.5% with sublingual buprenorphine (adjusted difference, 1.6%; 95% CI, -2.8% to 6.0%). Engagement at 30 days was similar, with adjusted proportions of 43.8% with extended-release buprenorphine vs 44.9% with sublingual buprenorphine (adjusted difference, -1.5%; 95% CI, -6.2% to 3.2%). Precipitated withdrawal was rare: 6 (0.6%) with extended-release buprenorphine and 8 (0.8%) with sublingual buprenorphine. Overdose events within 30 days occurred in 18 participants (2.3%) in each group. Patients receiving extended-release buprenorphine reported lower mean craving scores at 7 days vs those receiving sublingual buprenorphine (scale, 0-100; mean score, 26.5 vs 30.2, respectively; adjusted mean difference, -3.85; 95% CI, -7.08 to -0.63), fewer days of illicit opioid use in the past 7 days (adjusted ratio of means, 0.77; 95% CI, 0.68-0.95), and better treatment satisfaction scores (scale, 1-5; adjusted mean difference, 0.13; 95% CI, 0.01-0.25). Conclusions and Relevance: No difference was detected in opioid use disorder treatment engagement on day 7 between the 7-day extended-release and sublingual buprenorphine groups. Both buprenorphine formulations were well tolerated; precipitated withdrawal was rare despite a high prevalence of fentanyl. Trial Registration: ClinicalTrials.gov Identifier: NCT04225598.