Concerned about your own or
someone else’s drug use?

Methamphetamine (MA) dependence is a growing public health concern. There is currently no pharmacotherapy approved for methamphetamine dependence. Lisdexamfetamine dimesylate (LDX), used in the treatment of Attention-Deficit Hyperactivity Disorder (ADHD) and binge eating disorder, has potential as an agonist therapy for MA dependence, and possible benefits of reduced risk of aberrant use due to its novel formulation.

A double-blind randomised controlled trial is underway to evaluate the efficacy of LDX in reducing MA use. The target sample is 180 participants with MA dependence of ≥ 2 years, using ≥ 14 days out of the previous 28. Participants will be randomly assigned to receive a 15-week intervention consisting of LDX or placebo. LDX will be administered in three phases: induction (1 week of 150mg LDX daily), maintenance (12 weeks of 250mg LDX daily) and reduction (1 week of 150mg and 1 week of 50mg LDX daily). All participants will be given access to 4 sessions of CBT as treatment-as-usual and receive a 4-week follow up appointment. The primary outcomes are efficacy (change from baseline in days of methamphetamine use by self-report for the last 28 days at week 13, and urinalysis confirmation of methamphetamine use) and safety (treatment related adverse events). Secondary outcomes are total number of days of self-report MA use over the 12 week active treatment, longest period of abstinence during treatment period, percentage of achieving >= 21 days abstinence, craving, withdrawal, dependence, retention, blood borne virus transmission risk behavior, criminal behaviour, as well measures of abuse liability, physical and mental health, other substance use, cognitive performance, psychosocial functioning, treatment retention and satisfaction. Additionally, the study will assess the cost effectiveness of LDX relative to the placebo control.

This investigator initiated study proposes to deliver the medication in an outpatient setting allowing participants take-home dosing to more closely mimic the service delivery situations in which the medication may be used. If efficacious further dose-response relationship studies may be indicated to explore optimum duration of treatment and a reducing regimen. The intervention could provide a much needed therapeutic adjunct for people who are dependent on MA.

This application will extend the currently active multi-centre clinical trial to add an additional site at Royal Prince Alfred Hospital Drug Health Service (RPAH-DHS). In this way, the progress of this trial will be accelerated, the necessary expertise will be transferred to RPAH-DHS and the capacity of this service for future research into MA and related drugs will be expanded.

The LiMA study will benefit from an additional site to achieve recruitment targets and this application will support recruitment and treatment of 25 additional participants.