May 13, 2021
2 min read
The researchers report no relevant financial disclosures.
Cannabis, cannabis-derived products and synthetic cannabinoids may slightly decrease rheumatoid arthritis disease activity, according to a meta-analysis published in the Journal of Clinical Rheumatology.
However, the researchers cautioned that the evidence suggests that such products result in “little to no difference” in pain relief and may slightly increase the risk for nervous system adverse events.
“Despite great advances in RA treatment, symptoms and disease burden still cause disability, poor quality of life and significant excess mortality, which sometimes lead patients to seek therapeutic alternatives,” Clara Schulze-Schiappacasse, MD, of the Pontifical Catholic University of Chile, and colleagues wrote.
“Although the mechanism of action of cannabis, cannabis-derived products, and synthetic cannabinoids in rheumatic diseases remains unclear, patient’s interest in their medical use is rising,” they added. “This fact, along with the lack of a strong evidence support, has led physicians to face great uncertainty about the benefits and risks of their prescription.”
To examine whether cannabis, cannabis-derived products and synthetic cannabinoids are effective in treating RA, Schulze-Schiappacasse and colleagues performed a structured summary of the available evidence. They conducted an electronic search in the Epistemonikos database to identify systematic reviews and their primary studies, and later collected the resulting data in a pivot table. In all, the researchers identified and included 26 systematic reviews — including just one randomized, controlled trial regarding the use of cannabis products in RA — in their analysis.
This single trial included 58 patients and examined pain on movement, pain at rest, total pain intensity, morning stiffness, sleep quality, disease activity and adverse effects. Schulze-Schiappacasse and colleagues reanalyzed the extracted data and drafted a summary of findings using the Grading of Recommendations Assessment, Development and Evaluation approach.
The researchers produced the following summary of findings:
- Cannabis, cannabis-derived products and synthetic cannabinoids may slightly improve disease activity;
- Evidence suggests that such products offer “little to no difference” in pain reduction;
- The researchers found no studies that examined physical disability or quality of life;
- The evidence is “very uncertain” regarding the impact of cannabis, cannabis-derived products and synthetic cannabinoids on the risk for serious adverse events; and
- Cannabis, cannabis-derived products and synthetic cannabinoids may slightly increase the risk for nervous system adverse events.
“Existing evidence should lead most patients and physicians to exercise caution in using this intervention,” Schulze-Schiappacasse and colleagues wrote. “However, given the connotation of natural medicines of cannabis-derived products and cannabis in particular, it is likely that some clinicians and patients might favor its use despite the information provided in this summary.”
“The likelihood that the conclusions of this summary change with future evidence is high, given the scarcity of studies on the topic and the very low certainty of the evidence,” they added. “Also, further research is needed addressing cannabis, cannabis-derived products and synthetic cannabinoids other than nabiximols. At least three ongoing studies that could provide relevant clinical information were identified; all of them were randomized clinical trials. Ongoing primary studies and high-quality systematic reviews reanalyzing existing data could provide conclusions with higher certainty.”