A Randomised Controlled Trial (RCT) of a Diazepam Maintenance Intervention versus Standard Care of Tapering Diazepam to Reduce Dependent Street Benzodiazepine Use in Adults Receiving Opioid Agonist Treatment (OAT) (The In-BOAT Trial)
People who are dependent on street benzodiazepines while receiving opioid agonist treatment will be offered a steady daily dose of prescribed diazepam instead of the standard tapering regimen, to see if this reduces their use of illicit pills. This matters because mixing street benzodiazepines with opioids sharply raises the risk of overdose and drug-related death, yet clinicians lack clear evidence on how best to manage this common form of co-dependency. Current practice—gradually reducing the prescribed dose to zero—often fails, leaving patients to return to unpredictable street supplies. If the maintenance approach works, it could change clinical guidelines across the UK. Instead of pushing patients toward abstinence from benzodiazepines, services might offer long-term, supervised prescribing as a harm-reduction strategy. This would directly affect the everyday safety of people in treatment, potentially cutting overdose rates, hospital admissions, and deaths. The trial will also track cost-effectiveness, so funders can judge whether the intervention is affordable at scale. A process evaluation will capture patient and staff experiences, helping services understand what makes the approach succeed or fail in practice.
View original technical description
Research Question: Can a diazepam maintenance intervention reduce harmful street benzodiazepine use compared to a standard tapering dose of diazepam? Background: The use of street benzodiazepines with opiates increases risk of drug related harm including overdose and drug related deaths (DRD). Evidence on how best to manage co-dependency is insufficient. Aim: To conduct a two-arm RCT to test the clinical and cost effectiveness of a diazepam maintenance intervention vs a tapering dose of diazepam, to determine which results in greater reductions in street benzodiazepine use in adults receiving OAT in the UK. Objectives, to: 1. test the effectiveness of the diazepam maintenance intervention against standard care -a tapering dose of diazepam -in reducing street benzodiazepine use over 12 months; 2. measure substance use disorder outcomes and effectiveness at reducing harmful substance use (bingeing, mega-dosing, polydrug use, overdose), treatment retention and health and wellbeing outcomes (anxiety, depression, quality of life, substance use recovery, patient acceptability and cognitive function) between arms; 3. assess the cost effectiveness and cost consequence of the intervention compared to standard care from a health and social care perspective; 4. review emergence of new street benzodiazepines through toxicological surveillance and adjust accordingly; 5. undertake a process evaluation to assess retention, adherence, and experiences of people in each arm to understand the success or otherwise of the intervention. Method: A two-arm RCT with a cost effectiveness study and mixed methods process evaluation. Six sites across Scotland and England will recruit 230 people in OAT with co-occurring benzodiazepine dependence. Participants will be randomised 1:1 to intervention or control. An internal pilot will test recruitment and randomisation; at the end of a 6-month pilot we expect to randomise 91 participants with progression criteria of green (100%), amber (60–100%) and red (<60%). Intervention: A maintenance daily dose of 30mg diazepam with tailored psychosocial support delivered by a trained nurse/support worker. Control: A tapering diazepam dose from a maximum of 30mg daily diazepam reduced flexibly in 2mg increments, to zero dose by 6 months. Primary Outcome: Street benzodiazepines use determined by toxicology via monthly oral fluid swab over 12 months. Secondary Outcomes: Substance use status; high dose and polydrug use; heavy drinking days; changes in anxiety, depression, memory & cognition; days of abstinence; drug use trajectory; overdose; quality of life; occupational & education status; participant acceptability; participant reported recovery; treatment retention; adherence; adverse events; hospital admissions. The economic evaluation is a within trial cost effectiveness and cost-consequence analysis, producing outputs to support modelling of long-term cost-effectiveness. A mixed method process evaluation will explore recruitment, retention, fidelity, adherence, experiences, and implementation potential, through interview and descriptive statistics. Timelines for Delivery (months): prefunding: regulatory approvals; 0-7: site set up; 8-9: Site staff recruitment/training; 9-15: internal pilot; 9-21: recruitment; 21-36: data collection; 37-45: analysis/reporting/dissemination. Dissemination and Anticipated Impact: Outcomes will be presented at conferences and shared with UK bodies to inform clinical guidelines
Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.
Is something wrong? Let us know