Real-world outcomes with extended-release buprenorphine (XR-BUP) in a low threshold bridge clinic: A retrospective case series.

Background: In clinical trial settings, extended-release buprenorphine (XR-BUP) is noninferior to sublingual buprenorphine and may offer some advantages. However, real-world experiences of XR-BUP are limited and outcomes are unknown for low-threshold clinics with high-risk populations. Practical guidance is lacking on overcoming treatment challenges, such as inability for some to stabilize on sublingual (SL) BUP for seven days prior to XR-BUP and ongoing craving/withdrawal symptoms during treatment.

Methods: Retrospective case series of a convenience sample of 40 serial adults with opioid use disorder (OUD) treated with XR-BUP from Massachusetts General Hospital bridge clinic from February 1, 2019, to July 31, 2019.

Results: Patients were mostly male (67.5%), non-Hispanic white (97.5%), unstably housed (77.5%), and average age of 32.1 years old. The average SL BUP dose prior to XR-BUP was 18.6 mg (standard deviation [SD] = 5; range 8-32) for an average treatment duration of 105 days (SD = 191; range 1-810). Ten (25%) patients received SL BUP for fewer than the seven recommended days (mean = 3.7, SD = 1.4, range = 1-6). Standard induction dosing was administered to 30%, empiric high-dose XR-BUP (300 mg monthly) was administered to 25%, and 55% were treated with supplemental SL BUP ranging from 4 to24mg, daily or as needed, for varying time periods. At the end of data collection, 65% remained on XR-BUP, 30% discontinued XR-BUP, and one patient was lost to follow-up. Acute care utilization rates were similar between patients who continued XR-BUP versus discontinued at 18.5% and 16.6%, respectively (χ = 0.02, p-value = 0.89). Toxicology was negative for other opioids in 65% of patients throughout treatment. There were no reports of overdose, withdrawal after use of opioids, or precipitated withdrawal after subsequent XR-BUP. Patients' most cited reason for discontinuing XR-BUP was a preference for SL BUP.

Conclusion: This real-world evaluation of XR-BUP in a low-threshold clinic found that treatment was feasible, well tolerated, and outcomes were good, with most individuals choosing to continue treatment and a majority with no evidence of ongoing opioid use or precipitated withdrawal.