(114) Early Uptake and Utilization Patterns of Long-Acting Injectable Buprenorphine

Background & Introduction: Evaluations of early uptake and utilization patterns of novel medications for opioid use disorder (MOUD) can help identify disparities in treatment initiation and guide targeted interventions to ensure equitable care delivery. Long-acting injectable buprenorphine (LAIB) was first approved in the United States in November 2017 and has become an important treatment and harm reduction strategy for opioid use disorder (OUD).1,2 By reducing daily medication burden and supporting sustained therapeutic buprenorphine levels, LAIB may improve treatment engagement, particularly for patients facing barriers to care. However, the determinants of early uptake and utilization patterns of LAIB during its initial years of clinical availability are largely unknown. This study characterizes early LAIB utilization and identifies predictors of use within three integrated primary care-based clinics providing MOUD.

Methods: We conducted a retrospective cohort study using electronic health record data across three integrated internal medicine practices within a single urban, academic health system between 1/1/2018 and 9/30/2023 (index period). The study period corresponds with the first six calendar years of LAIB market-availability in the US. Inclusion criteria were: (1) adults (≥18 years), (2) with a diagnosis of OUD, (3) who had ≥1 outpatient visit for MOUD at one of the study sites during the index period (index visit). The baseline period was 12 months prior to the index visit date, and follow-up continued for 6 months after the index visit date. The primary outcome was receipt of LAIB at any time within the first 6-months of care.

As a secondary objective, we evaluated utilization patterns, including new initiation, continuation, discontinuation, and switch to alternative therapy (ie oral bupreorphrine or methadone) for patients who received LAIB. Descriptions of MOUD use prior to index visit were captured from clinical notes. Univariable logistic regression was used to examine determinants of LAIB receipt, including demographics, referral pathway, prior MOUD history, and care engagement metrics.

Results: Among the 412 patients who met our study criteria, 44 (10.7%) received at least one dose of LAIB within six months of their index visit. Of these patients, 35 received their first-ever dose of LAIB during the study period. Three of these “first-ever” patients received LAIB at their first visit (index visit) and 32 received it at some other point during the 6-month follow-up period. Of the patients who received LAIB during the study period, 36 (81.8%) remained engaged in care at 6 months post-index visit; among these, 26 (72.2%) remained on LAIB, 9 (25.0%) transitioned to oral buprenorphine, and 1 (2.8%) discontinued MOUD.

Eighteen patients had documented LAIB exposure prior to their index visit, having received LAIB at outside facilities before establishing care at the study clinics. Of these, 9 (50%) did not receive a subsequent dose during follow-up and instead transitioned to oral buprenorphine. Among the 9 patients who received LAIB prior to index visit and went on to receive at least one subsequent dose at a study clinic, three (33%) received LAIB at the index visit, while the remaining six received oral buprenorphine at index visit and then transitioned to LAIB during follow-up. Of patients with prior LAIB experience, only one had documentation of consistent LAIB treatment before index; everyone else had received a one-time dose in a different setting such as an emergency room.

In univariable analyses, receipt of LAIB at a study clinic was associated with receipt of LAIB prior to index (OR 9.80, 95% CI 3.56–26.95); engagement with a certified recovery specialist during the study period, (OR 2.65, 95% CI 1.24–5.67); and persistent opioid-positivity on urine drug screens (UDS), which was defined as detection of opioids in both the first and last UDS collected during the study period (OR 2.58, 95% CI 1.21-5.50). Compared with White patients, Black patients were less likely to receive LAIB (OR 0.46, 95% CI 0.23–0.93). Age, sex, insurance status, psychiatric comorbidity, MOUD visit frequency, and provider type were not significantly associated with LAIB use.

Conclusion & Discussion: Our study found limited LAIB uptake in primary care-based MOUD clinics during the first six years of market availability, consistent with prior findings of slow adoption of novel MOUD in in organized healthcare systems.³ However, among patients who initiated LAIB and remained in care at six months, most continued LAIB through the end of follow-up. Early exposure to LAIB, including initial doses received in other settings before the index period, strongly predicted subsequent use, highlighting how low-barrier initiation may facilitate early adoption of harm-reduction strategies. The association between LAIB use and engagement with integrated recovery specialists aligns with evidence that multidisciplinary, team-based care models improve MOUD uptake.⁴ Additionally, higher LAIB utilization among patients with persistently opioid-positive urine drug screens suggests that harm-reduction-oriented prescribing may shape early uptake patterns. Most patients did not receive LAIB at their first visit, which may reflect logistical barriers and patient preferences to defer initiation until a trusting relationship was established. Finally, lower LAIB uptake among Black patients highlights persistent structural barriers and racial inequities in accessing newer, resource-intensive treatments. Together, these findings suggest that equitable expansion of LAIB will require not only increased availability but also intentional implementation strategies addressing care continuity and racial disparities.

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2. Springer SA. Is high-dose extended-release buprenorphine safe and effective for persons who use fentanyl? JAMA Netw Open. 2025;8(12):e2548043. doi:10.1001/jamanetworkopen.2025.47965.

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4. Harris LM, Guerrero EG, Khachikian T, Serrett V, Marsh JC. Expert providers implement integrated and coordinated care in opioid use disorder treatment. Int J Drug Policy. 2024;132:104567. doi:10.1016/j.drugpo.2024.104567.