Cannabis Tied to Rebound Headaches in Chronic Migraine Patients

Migraine patients who used cannabis were more likely to develop “rebound” or medication overuse headaches than those who didn’t use cannabis, a single-center chart review suggested.

In an analysis of 368 patients with chronic migraines, current cannabis use predicted cases of medication overuse headache (OR 5.99, 95% CI 3.45-10.43, P<0.0001), reported Niushen Zhang, MD, and Yohannes Woldeamanuel, MD, both of Stanford University School of Medicine in California, in an abstract released in advance of the American Academy of Neurology annual meeting.

Medication overuse headache is a result of frequent use of pain medications for headaches. “Cannabis affects the endocannabinoid system in the brain, which plays a role in pain processing,” Zhang and Woldeamanuel said.

“There is moderate evidence to support the use of cannabis for the treatment of chronic pain,” they added. “However, there is emerging anecdotal clinical evidence that use of cannabis may lead to medication overuse headache.”

Recent research from Washington State University in Pullman showed that inhaled cannabis reduced self-reported migraine severity by 49.6%. That study found no evidence of cannabis leading to overuse headache, but researchers noticed patients using larger doses of cannabis over time, indicating possible tolerance to the drug.

Zhang and Woldeamanuel used the Stanford Research Repository cohort discovery tool between 2015 to 2019 to evaluate adults who had chronic migraines for at least 1 year. Chronic migraine was defined as 15 or more headache days per month. Of 368 patients in the study, 150 were using cannabis.

From each patient’s chart, the researchers extracted data about age, sex, migraine frequency, current chronic migraine duration, current cannabis use duration, overused acute migraine medications, and duration of current medication overuse headache. They used logistic regression to identify variables predicting overuse headache while controlling for the remaining predictors.

Overall, 212 patients had medication overuse headache and 156 did not. Significant associations were seen between current cannabis use, opioid use, and overuse headache.

A bi-directional relationship between cannabis and opioid use also emerged. “Use of one increased use of the other,” Zhang and Woldeamanuel wrote. Analysis showed two clusters of chronic migraine patients, with patients in one cluster being younger and having less migraine frequency, higher overuse headache burden, and more current cannabis and opioid users than the other.

A limitation of the study was its retrospective nature, the researchers noted. Longitudinal studies are needed to further explore relationships between cannabis and overuse headache in chronic migraine patients, they said.