Medicinal cannabis: is current use clinically justified?

Abstract

Cannabis products are increasingly perceived and advertised as natural and safe treatments for a variety of conditions, including chronic non-cancer pain (CNCP). The number of prescriptions for medicinal cannabis (MC) currently averages >80 000 per month for >1 million Australians. Although over 800 different cannabis products are available to prescribe in Australia, only two are registered on the Australian Register of Therapeutic Goods and approved by the Therapeutic Goods Administration for specific clinical indications. Using treatment for CNCP as an example, evidence of efficacy across nine systematic reviews was inconsistent and/or of low quality and, with the exception of neuropathic pain, was unable to identify patient phenotypes in whom a specific type and dosing of cannabis product can reliably provide sustained symptomatic relief. Professional bodies do not endorse unregulated or first-line use of cannabis for CNCP. Harm from cannabis is under-reported but adverse effects include impaired cognitive function, dizziness, sedation, confusion, psychosis and arrhythmias, potentially more so in older patients. Healthcare professionals must inform patients of the significant limitations of current evidence of efficacy and safety for cannabis use in CNCP and other conditions and resist media and industry pressures for greater access to and prescribing of MC.