Two concurrent randomised placebo controlled trials of modafinil in methamphetamine and cocaine dependence

NDARC Staff

Richard Mattick, James Shearer, Rebecca McKetin and Shane Darke

Other Investigators

Alex Wodak, (St Vincent’s Hospital Alcohol and Drug Services), Ingrid van Beek (Kirketon Road Centre) and John Lewis (Pacific Laboratory Medicine Services)

Aims

Modafinil is a novel wake promoting agent which may have potential in the treatment of psychostimulant dependence withdrawal symptoms including low mood, excessive sleepiness, poor concentration and drug craving thereby protecting against relapse. Modafinil is well tolerated with few major side effects and appears to have a low abuse liability. The aim of the two studies is to evaluate the safety and efficacy of modafinil (200 mg/day over 10 weeks), and a brief cognitive behavioural therapy (CBT) program for psychostimulant (cocaine and methamphetamine) dependence.

Design and Method

Two concurrent randomised placebo controlled trials were conducted at the Kirketon Road Centre, a primary health care centre and Rankin Court, an alcohol and drug treatment centre, both located in inner city Sydney. Recruitment targets were 60 for the amphetamine study and 30 in the cocaine study. Subjects in both studies were randomised equally to two groups. The experimental groups received a modafinil dose of 200 mg/day under a weekly script for 10 weeks. The control group received placebo under equivalent conditions. Both groups were offered a four-session manualised brief CBT intervention designed for amphetamine users. Treatment efficacy was primarily evaluated by a between group comparison of the proportion of urine samples negative for psychostimulant over 10 weeks. Safety was evaluated by between group comparison of side effects and adverse events. Self-reported stimulant use, other drug use and retention were compared between groups. Improvements in health and psychosocial harms associated with regular stimulant use and patterns of use were also compared.

Treatment retention was equivalent between the groups. There were no statistically significant between group differences in treatment outcome measures for the combined methamphetamine/cocaine sample. The degree of uptake of counselling was the most significant predictor of better post treatment outcomes. There were no medication related serious adverse events. Adverse events were generally mild and consistent with known pharmacological effects.

Benefits

The project is an original and rigorous contribution to the development of effective treatments in an area where few treatments currently exist and treatment need is great and growing. Results will be of wide national and international interest to service providers, research, policy makers and stimulant users.

Funding

Australian Government Department of Health and Ageing