Relationship Between Nociplastic Pain Involvement and Medication Use, Symptom Relief, and Adverse Effects Among People Using Medical Cannabis for Chronic Pain

Objectives:Cannabis is increasingly being used for chronic pain management, but cannabis' effects remain poorly characterized in chronic nociplastic pain (NPP), which is posited to be caused by disturbances in nervous system pain processing. In this cross-sectional study (n=1213), we used the 2011 Fibromyalgia (FM) Survey Criteria as a surrogate measure for degree of NPP among individuals using medical cannabis for chronic pain. Methods: Using a quartile-split, we investigated associations between the degree of NPP and medication use, cannabis use characteristics, and symptom relief. Continuous variables were assessed using one-way analysis of variance and categorical variables with Pearson chi(2) test and binomial logistic regression for calculation of odds ratios. Results:Participants were predominately female (59%), with a mean +/- SD age of 49.4 +/- 13.6 years. Higher FM scores were associated with less self-reported improvement in pain and health since initiating medical cannabis use, as well as more cannabis-related side effects. Paradoxically, higher FM scores were also associated with higher usage of concomitant medication use (including opioids and benzodiazepines) but also with substituting cannabis for significantly more medication classes, including opioids and benzodiazepines. Discussion: This article presents evidence that individuals in higher NPP quartiles have higher analgesic intake, higher odds of substituting cannabis for medications, higher side effect burden, and lower therapeutic effect from cannabis. These seemingly contradictory findings may reflect higher symptom burden, polypharmacy at baseline, or that NPP may be challenging to treat with cannabis. Further research is necessary to further explain cannabinoid effects in NPP.