Impact of dextroamphetamine substitution on the use of illicit amphetamines in adults with amphetamine dependence: a study protocol for the multicentre double blind randomised controlled trial ATLAS4Dependence.

introductionThere is limited evidence on how to effectively treat individuals from marginalised populations with dependence on amphetamine and/or methamphetamine (collectively referred to hereafter as amphetamine dependence). The disease burden is extremely high in this population, especially related to psychiatric comorbidities, cardiovascular complications, injection-related infections and poor social functioning. ATLAS4Dependence is a multi-centre randomised, placebo-controlled, double-blind trial that will investigate the effectiveness and safety of substitution treatment with dextroamphetamine compared with placebo in people with amphetamine dependence. METHODS AND ANALYSIS: The trial will recruit 226 adult patients in several outpatient clinics in Norway. Inclusion criteria comprise individuals with amphetamine dependence, defined as use on three or more days per week during the past 28 days, who currently inject or have formerly injected drugs. This includes individuals both with and without comorbid opioid dependence, as well as those currently receiving or not receiving opioid agonist treatment. Participants will be randomly assigned 1:1 to receive either dextroamphetamine or placebo for 12 weeks. Flexible doses within the range of 30-120 mg daily will be provided based on individual assessments. The participants in both arms will be offered standard psychosocial and medical follow-up in accordance with current clinical practice. The endpoint assessments will be conducted at 12 weeks with weekly self-reports and safety assessments and a follow-up assessment at 52 weeks. The primary objective of the study is to assess the impact of 12 weeks daily prescribed oral dextroamphetamine versus placebo on the use of illicit amphetamines as well as on the total amount of amphetamines used (including both illicit and prescribed sources). Secondary outcomes are the differences between the groups at 12 weeks regarding psychological distress, symptoms of psychosis, quality of life, cardiovascular risk factors, injection-related infections, executive functioning, attention-deficit hyperactivity disorder-related symptoms, sleep, violence risk, fatigue, symptoms of craving and withdrawal, treatment retention, days of use of illicit amphetamines and use at 4 weeks and 8 weeks during the intervention period, use of other illicit substances and alcohol, as well as a cost-effectiveness analysis (using private economy, criminal activity and health service utilisation) and a qualitative approach to assess overall experiences with the study intervention. Analysis and reporting will follow the Consolidated Standards of Reporting Trials guidelines. All tests will be two-sided. Descriptive results and the estimated effectiveness will be presented with 95% CIs. The difference between the groups at the primary time point (at the end of the 12-week trial) will be assessed using χ ETHICS AND DISSEMINATION: The study is approved by European Medicines Agency, Clinical Trial Information System (CTIS). Written informed consent will be obtained from all patients. Study results will be published in international peer-reviewed medical journals. TRIAL REGISTRATION NUMBER: CTIS 2023-510404-44-00.