Efficacy, tolerability and safety of cannabis-based medicines for chronic pain management - An overview of systematic reviews.

Medicinal cannabis has already entered mainstream medicine in some countries. This systematic review (SR) aimed at evaluating the efficacy, acceptability and safety of cannabis-based medicines for chronic pain management. Qualitative systematic review of SRs of randomized controlled trials with cannabis-based medicines for chronic pain management. The Cochrane databases of SRs, Database of Abstracts of Reviews of Effects and PubMed were searched for SR published in the period January 2009 to January 2017. Assessment of the methodological quality of SR was performed by the AMSTAR checklist. Out of 748 papers identified, 10 SRs met the inclusion criteria. The methodological quality was high in four and moderate in six SRs. There were inconsistent findings of four SRs on the efficacy of cannabis-based medicines in neuropathic pain and of one SR for painful spasms in multiple sclerosis. There were consistent results that there was insufficient evidence of any cannabis-based medicine for pain management in patients with rheumatic diseases (three SRs) and in cancer pain (two SRs). Cannabis-based medicines undoubtedly enrich the possibilities of drug treatment of chronic pain conditions. It remains the responsibility of the health care community to continue to pursue rigorous study of cannabis-based medicines to provide evidence that meets the standard of 21st century clinical care. SIGNIFICANCE: We provide an overview of systematic reviews on the efficacy, tolerability and safety of cannabis-based medicines for chronic pain management. There are inconsistent findings of the efficacy of cannabinoids in neuropathic pain and painful spasms in multiple sclerosis. There are inconsistent results on tolerability and safety of cannabis-based medicines for any chronic pain.