Development of an intravenous low-dose buprenorphine initiation protocol

Background: Buprenorphine is a life-saving treatment for opioid use disorder (OUD). Low-dose initiation (LDI) is an emerging buprenorphine initiation strategy that circumvents barriers associated with standard initiation. This study aims to describe tolerability and completion of LDI using intravenous (IV) buprenorphine and to define dosing protocols in a cohort of patients hospitalized in an urban academic hospital. Methods: Data was collected via retrospective chart review for IV buprenorphine LDI cases initiated between September 1, 2020 and February 28, 2021. Cases were excluded if diagnostic criteria for OUD was not met, Clinical Opiate Withdrawal Scale (COWS) scores were not recorded, or sublingual (SL) buprenorphine was given within 24 h before IV buprenorphine. Completion of LDI and COWS data were assessed for all cases. Cases were categorized based on adherence to a dosing strategy and LDI indication, including OUD and acute pain, non-prescribed fentanyl exposure, and transition from methadone. Results: Seventy-two cases were identified, and thirteen cases were excluded, leaving 59 cases in the population. Of these cases, 72.9% (43/59) tolerated LDI, and 91.5% (54/59) completed buprenorphine initiation. Forty-four (44/59, 75%) cases were adherent. Median duration of LDI within the adherent group was 23.7 h (IQR 22.8–27.0), 37.1 h (IQR 36.2–40.9), and 48.8 h (IQR 47.0–52.4) for the “rapid,” “moderate,” and “slow” dosing strategies, respectively. Conclusions: IV buprenorphine LDI was tolerated and completed in a majority of patients. Dosing protocols allowed for rapid transition to sublingual buprenorphine. Acute pain or recent methadone or fentanyl exposure may inform IV LDI dosing strategy selection.