Results of a retrospective study show that cannabis use significantly contributes to the prevalence of medication overuse headache (MOH) in patients with chronic migraine (CM). Individuals also exhibited a bidirectional cannabis-opioid association whereby use of one increased use of the other.
Based on the findings, researchers suggest it may be beneficial to advise patients with CM and MOH to reduce cannabis use to effectively treat MOH. The abstract will be presented at the American Academy of Neurology’s 73rd Annual Meeting, being held virtually between April 17-22, 2021.
MOH results from regular overuse of acute headache medications like triptans, ergots, barbiturates, or opiates among patents with pre-existing primary headache disorders. Cannabis affects the endocannabinoid system in the brain, which plays a role in pain processing, researchers explained. Although some evidence supports the use of cannabis for the treatment of chronic pain, anecdotal evidence suggests use of cannabis may lead to MOH.
To determine whether cannabis use predicts MOH in patients with CM, investigators used the Stanford Repository Cohort Discovery Tool to assess data of 368 adult patients with CM (150 using cannabis, 218 not using cannabis), who have had the condition for at least 1 year.
Data collected between 2015 and 2019 included variables such as age, sex, migraine frequency, current CM duration, current cannabis use duration, overuse of other medications for acute migraine, and information on MOH. Researchers then used logistic regression to identify variables predicting MOH while controlling for remaining predictors. In addition, agglomerative hierarchical clustering (AHC) was carried out to determine natural clusters using all predictor variables.
Of the patients with CM included, 212 experienced MOH while 156 did not. Analyses revealed:
- Current cannabis use statistically significantly predicted cases with MOH (odds ratio [OR] 5.99; P < .0001)
- Significant associations were found between current cannabis use, opioid use, and MOH
- AHC found cluster I patients were younger with less migraine frequency, higher MOH burden, more current cannabis and opioid users than cluster II
Overall, individuals using cannabis were 6 times more likely to have MOH than those who did not while patients using opioids were more likely to have current cannabis use. Both cannabis and opioids can influence the periaqueductal gray area of the brain which has been proposed as a possible generator of migraine attacks.
“Many people with CM are already self-medicating with cannabis, and there is some evidence that cannabis can help treat other types of chronic pain," said study author Niushen Zhang, MD. "However, we found that people who were using cannabis had significantly increased odds of also having MOH, or rebound headache, compared to people who were not using cannabis."
Because the analysis was retrospective, future longitudinal studies are needed to better understand cause and effect of cannabis use and MOH in patients with CM.
Zhang N and Woldeamanuel Y. Medication overuse headache in chronic migraine patients using cannabis: a case-referent study. Abstract presented at American Academy of Neurology 73rd Annual Meeting; April 17-22, 2021; Virtual. Accessed March 1, 2021.