Randomised clinical trial of a 16 mg vs 24 mg maintenance daily dose of buprenorphine to increase retention in treatment among people with an opioid use disorder in Rhode Island: study protocol paper

Introduction: Buprenorphine is a highly effective treatment for opioid use disorder (OUD). However, provider observations and preliminary research suggest that the current standard maintenance dose may be insufficient for suppressing withdrawal and preventing cravings among people who use or have used fentanyl. Buprenorphine dosing guidelines were based on studies among people who use heroin and have not been formally re-evaluated since fentanyl became predominant in the unregulated drug supply. We aim to compare the effectiveness of a high (24 mg) vs standard (16 mg) maintenance daily dose of buprenorphine for improving retention in treatment, decreasing the use of non-prescribed opioids, preventing cravings and reducing opioid overdose risk in patients.

Methods and analysis: Adults who are initiating or continuing buprenorphine for moderate to severe OUD and have a recent history of fentanyl use (n=250) will be recruited at four outpatient substance use treatment clinics in Rhode Island. Patients continuing buprenorphine must be on doses of 16 mg or less and have ongoing fentanyl use to be eligible. Participants will be randomly assigned 1:1 to receive either a high (24 mg) or standard (16 mg) maintenance daily dose, each with usual care, and followed for 12 months to evaluate outcomes. Providers will determine the buprenorphine initiation strategy, with the requirement that participants reach the study maintenance dose within 7 days of randomisation. Providers may adjust the maintenance dose, if clinically needed, for participant safety. The primary study outcome is retention in buprenorphine treatment at 6 months postrandomisation, measured using clinical and statewide administrative data. Other outcomes include non-prescribed opioid use and opioid cravings (secondary), as well as non-fatal or fatal opioid overdose (exploratory).

Ethics and dissemination: This protocol was approved by the Brown Institutional Review Board (STUDY00000075). Results will be presented at conferences and published in peer-reviewed journals.

Trial registration number: NCT06316830.