Evaluation of an injectable monthly extended-release buprenorphine program in a low-barrier specialty addiction medicine clinic

Introduction: Monthly injectable extended-release buprenorphine (XR-BUP) can address several systemic and individual barriers to consistent sublingual buprenorphine treatment for patients with opioid use disorder (OUD). Real-world evaluations of XR-BUP in the outpatient addiction treatment setting are limited. The purpose of this study was to compare 6-month treatment retention and urine drug tests between patients who initiated XR-BUP compared to those who were prescribed but did not initiate XR-BUP in a low-barrier addiction medicine specialty clinic.

Methods: We conducted a retrospective cohort study of adults with OUD prescribed XR-BUP between 12/1/2018 and 12/31/2020 in a low-barrier addiction medicine specialty clinic to compare 6-month treatment retention between patients who initiated XR-BUP and those who were prescribed but did not initiate XR-BUP (comparison group). Secondary outcomes included percent of urine toxicology tests negative for non-prescribed opioids. Multivariable logistic regression models evaluated factors associated with 6-month treatment retention and XR-BUP initiation.

Results: Of the 233 patients prescribed XR-BUP, 148 (63.8 %) identified as non-Hispanic white, 218 (93.6 %) were insured by public insurance (Medicare/Medicaid), and nearly two-thirds were prescribed XR-BUP due to unstable OUD. Approximately 50 % of patients initiated XR-BUP treatment (mean number of injections = 3.7). About 60 % of XR-BUP-treated patients received supplemental sublingual buprenorphine and nearly two-thirds received a 300 mg maintenance dose. Six-month treatment retention was greater in the XR-BUP treatment versus comparison group (70.3 % vs. 36.5 %, p < 0.001). The XR-BUP treatment group had a higher percentage of opioid-negative urine toxicology tests versus the comparison group (67.2 % vs. 36.3 %, p < 0.001). Receipt of XR-BUP was an independent predictor of 6-month treatment retention (OR 5.40, 95 % CI 2.18-13.38). Those prescribed XR-BUP due to unstable OUD had lower odds of treatment retention (OR 0.41, 95 % CI 0.24-0.98) after controlling for receipt of XR-BUP and other variables known to impact retention.

Conclusions: XR-BUP improved 6-month treatment retention and resulted in a greater proportion of opioid-negative urine toxicology tests compared to a comparison group of patients who were prescribed but did not initiate XR-BUP. Patients with unstable OUD had lower odds of XR-BUP initiation, suggesting the need for targeted interventions to increase XR-BUP uptake in this high-risk population.