Cannabinoids have limited efficacy in improving the symptoms of multiple sclerosis (MS), authors of a systematic review and meta-analysis have concluded
Reporting their results in JAMA Network Open (12 October 2018), the researchers used data from 17 randomised controlled trials looking at the effects of oral or oromucosal medicinal cannabinoids involving a total of 3,161 patients with MS.
They found that the effect of cannabinoid treatment on subjectively measured spasticity, pain and bladder dysfunction was mild compared with placebo. There was no significant impact on objectively measured spasticity.
Active treatment was associated with an increased risk of adverse events (rate ratio 1.72 patient-years; 95% confidence interval, 1.46–2.02 patient-years). However, the risk of serious adverse events was not significantly different to placebo, leading the researchers to conclude the drugs could be considered safe.
“To our knowledge, this is the most complete systematic review and meta-analysis of the effect of cannabinoids on MS,” the researchers wrote.
“Our results show limited therapeutic efficacy of cannabinoids for the primary outcomes of spasticity, pain, and bladder dysfunction in patients with MS.”
 Torres-Moreno M, Papaseit E, Torrens M et al. Assessment of efficacy and tolerability of medicinal cannabinoids in patients With multiple sclerosis. JAMA Netw Open 2018;1:e183485. doi:10.1001/jamanetworkopen.2018.3485