ASSOCIATIONS BETWEEN FATTY ACID AMIDE HYDROLASE VARIANTS AND RESPONSE TO CANNABIS USE FOR PAIN MANAGEMENT IN RHEUMATOID ARTHRITIS
Authors: Kristin Wipfler et al.
This study explored the hypothesis that genetic variations involving the cannaboid receptor may explain differences in the use and the effectiveness of the cannabis by RA patients. 365 RA patients from the US FORWARD register answered detailed questions on cannabis use as a treatment for arthritic pain and provided blood samples for genotyping.
One third of RA patients reported using cannabis for arthritic pain, and of these, 52% felt that cannabis was reducing their pain. The authors then analyzed polymorphisms of the FAAH gene, which is involved at the cannabinoid receptor level. One variant was associated with cannabis use (OR 1.9), and another was strongly associated with the perception of effectiveness of cannabis (OR 5.2).
Since cannabidiol (CBD) products became legal in Switzerland, an increasing number of rheumatic patients are trying cannabis derived products against arthritic pain. This study demonstrates that we may not all be equally equipped to benefit from this drug: Some genetic variants of the FAAH gene are associated with a five times greater likelihood of finding cannabis effective in reducing pain, while other genetic variants make it fairly unlikely that the patient finds benefit from this drug. Interestingly, FAAH polymorphisms have previously been implicated in cannabis use in humans, and in joint pain reduction in mouse models.