Evidence based review of current therapies under trial for treatment of cannabis use disorder

June 2016
Copeland, J., & Pokorski, I. (2016). Progress toward pharmacotherapies for cannabis-use disorder: an evidence-based review. Substance Abuse and Rehabilitation, 7, 41-53. doi: http://dx.doi.org/10.2147/SAR.S89857

Cannabis is the most widely used and variably regulated drug in the world, with increasing trends of use being reported in the US, Australia, Asia, and Africa. Cannabis users infrequently seek professional treatment, and normally do so after a decade of use. Cannabis-use disorders are currently treated using a selection of psychosocial interventions. Severity of withdrawal is a factor that increases the risk of relapse, and is the target of pharmacotherapy studies. Currently, there is no approved pharmacotherapy for cannabis-use disorders. A number of approaches have been examined, and trials are continuing to find a safe and effective medication with little abuse liability. The authors have reviewed all current trials of pharmacotherapies.

Lead author of the review Professor Jan Copeland Director of the National Cannabis Prevention and Information Centre is chief investigator of the Sativex Trial which has proved promising in the management of cannabis withdrawal symptoms among dependent users in treatment The review summarises all current and completed trials of potential – 36 in total. It summarises the range of pharmaceuticals which have been trialled in hopes of aiding cessation of cannabis, from cannabinoids, opioid agonists and antagonists, anti-depressants, to the hormone oxytocin. Cannabinoid medications, agonists and antagonists, target the cannabinoid receptors activated by THC. Agonist substitution replaces THC, and antagonist therapy blocks the THC.

The most promising according to the review are the newer agonist therapies, such as nabiximols and nabilone, which have been found to reduce measures of withdrawal and relapse, warranting further exploration in the management of aspects of cannabis-use disorder. It is anticipated that as the evidence base for full and partial CB1-receptor agonists is developed, these medications will become cost-effective and accessible. The therapies that have been least promising, to date include the antagonist rimonabant. Other therapies currently being explored include cannabidiol (CBD) and fatty acid amide hydrolase (FAAH) inhibitors.