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.
OBJECTIVE: To determine the effects of medical cannabinoids on pain, spasticity, and nausea and vomiting, and to identify adverse events.
DATA SOURCES: MEDLINE, the Cochrane Database, and the references of included studies were searched.
STUDY SELECTION: Systematic reviews with 2 or more randomized controlled trials (RCTs) that focused on medical cannabinoids for pain, spasticity, or nausea and vomiting were included. For adverse events, any meta-analysis for the conditions listed or of adverse events of cannabinoids was included.
SYNTHESIS: From 1085 articles, 31 relevant systematic reviews were identified including 23 for pain, 5 for spasticity, 6 for nausea and vomiting, and 12 for adverse events. Meta-analysis of 15 RCTs found more patients taking cannabinoids attained at least a 30% pain reduction: risk ratio (RR) of 1.37 (95% CI 1.14 to 1.64), number needed to treat (NNT) of 11. Sensitivity analysis found study size and duration affected findings (subgroup differences,
CONCLUSION: There is reasonable evidence that cannabinoids improve nausea and vomiting after chemotherapy. They might improve spasticity (primarily in multiple sclerosis). There is some uncertainty about whether cannabinoids improve pain, but if they do, it is neuropathic pain and the benefit is likely small. Adverse effects are very common, meaning benefits would need to be considerable to warrant trials of therapy.
BACKGROUND: There are conflicting interpretations of the evidence regarding the efficacy, tolerability, and safety of cannabinoids in pain management and palliative medicine.
METHODS: We conducted a systematic review (SR) of systematic reviews of randomized controlled trials (RCT) and prospective long-term observational studies of the use of cannabinoids in pain management and palliative medicine. Pertinent publications from January 2009 to January 2017 were retrieved by a selective search in the Cochrane Database of Systematic Reviews, the Database of Abstracts of Reviews of Effects, and Medline. The methodological quality of the SRs was assessed with the AMSTAR instrument, and the clinical relevance of quantitative data syntheses was assessed according to the standards of the Cochrane Collaboration.
RESULTS: Of the 750 publications identified, 11 SRs met the inclusion criteria; 3 of them were of high and 8 of moderate methodological quality. 2 prospective long-term observational studies with medical cannabis and 1 with tetrahydrocannabinol/cannabidiol spray (THC/CBD spray) were also analyzed. There is limited evidence for a benefit of THC/CBD spray in the treatment of neuropathic pain. There is inadequate evidence for any benefit of cannabinoids (dronabinol, nabilone, medical cannabis, or THC/CBD spray) to treat cancer pain, pain of rheumatic or gastrointestinal origin, or anorexia in cancer or AIDS. Treatment with cannabis-based medicines is associated with central nervous and psychiatric side effects.
CONCLUSION: The public perception of the efficacy, tolerability, and safety of cannabis-based medicines in pain management and palliative medicine conflicts with the findings of systematic reviews and prospective observational studies conducted according to the standards of evidence-based medicine.
The use of cannabinoids has been proposed as an analgesic for different painful conditions, especially for chronic pain refractory to usual treatment. However, its real efficacy and safety remains controversial. We sought to determine whether cannabinoids are an effective treatment for chronic non-cancer pain. To answer this question, we used Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We identified 37 systematic reviews including 41 studies overall, of which 32 were randomized trials relevant for the question of interest. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. We concluded it is not clear whether cannabinoids decrease pain in patients with chronic non-cancer pain because the certainty of available evidence is very low. On the other hand, they are associated with significant adverse effects.
Multiple beneficial effects have been proposed lately for cannabinoids in different clinical situations. Among them, it has been postulated they would control symptoms of multiple sclerosis. However, there is no consensus about their real clinical role. To answer this question, we searched in Epistemonikos database, which is maintained by screening multiple databases. We identified 25 systematic reviews including 35 studies overall, of which 26 were randomized trials. We extracted data, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. We concluded cannabinoids in multiple sclerosis do not reduce spasticity or pain, and are probably associated to frequent adverse effects.
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.
