DENVER, Colorado — Vaporized cannabis containing tetrahydrocannabinol (THC) and cannabidiol (CBD) may provide rapid and sustained relief of acute migraine pain with no serious side effects, new research suggests.
"In this single center randomized controlled trial across 247 treated migraine attacks, 4 puffs of vaporized THC-CBD mix were efficacious for acute migraine treatment," said study investigator Nathaniel Marc Schuster, MD, with University of California San Diego Center for Pain Medicine.
The superiority of THC-CBD over placebo was "unlikely explained by unmasking given that in our blinding analysis most patients who got THC actually did not think they got some THC," Schuster said.
He presented the results (Abstract S22.010) on April 16 at the American Academy of Neurology (AAN) 2024 annual meeting.
Sustained Pain Relief
Preclinical and retrospective studies point to antimigraine effects of cannabinoids, yet strong evidence of efficacy from a randomized controlled trial has been lacking.
The researchers tested the efficacy of cannabis for acute migraine in what they report is the first randomized, double-blind, placebo-controlled, crossover trial of adults with migraine.
Participants treated up to four separate moderate to severe migraine attacks, each with one of four different treatments. The four treatments were: 6% THC, 11% CBD, a mix of 6% THC and 11% CBD, or placebo flower from the National Institute on Drug Abuse that has a similar taste and smell to the other products.
The four treatments were vaporized in a randomized order, with at least 1 week washout between treatments. The primary endpoint was pain relief at 2 hours from vaporization. Secondary endpoints were freedom from pain and most bothersome symptom (MBS) at 2 hours from vaporization.
Of the 92 enrolled patients (mean age 41 years, 83% women), 19 treated zero migraine attacks thus leaving 73 patients who treated a total of 247 migraine attacks over the 1-year study.
The THC-CBD mix was superior to placebo at achieving pain relief (67.2% vs 46.6%; P = .016), pain freedom (34.5% vs 15.5%; P = .017), and MBS freedom (60.3% vs 34.5%; P = .005) at 2 hours.
The THC-CBD mix was also superior to placebo for sustained pain freedom at 24 hours and sustained MBS freedom at 24 and 48 hours.
There were no serious adverse events. The THC-CBD mix was better tolerated than THC-only was, with lower rates of euphoria and cognitive impairment and lower subjective highness, Schuster said.
Adverse events were more common with THC only (vs THC-CBD) "and this is really expected because CBD is known to bring down the side effects of THC," Schuster noted.
Summing up his presentation, Schuster said, "This is one single-center study, and, of course, we need more data. We need to study the rates of medication overuse headache and the rates of cannabis use disorder that may develop with the use of cannabis for migraine."
Cautious Optimism
Reached for comment, Hsiangkuo (Scott) Yuan, MD, PhD, Department of Neurology, Thomas Jefferson University, and director of clinical research, Jefferson Headache Center, Philadelphia, Pennsylvania, noted that the "statistically significant" differences between THC-CBD vs placebo on 2-hour pain relief, pain freedom and MBS freedom are "certainly very exciting, especially when no serious adverse event was reported."
"Since THC has a narrow therapeutic window for analgesia (too high causes psychoactive side effects and may even worsen the pain), its dosing needs to be carefully controlled. The study was wisely designed to ensure uniform dosing from the vaporizer, which is usually safer than smoking or a vape pen and has a quicker onset than ingestion for acute usage," Yuan, who was not involved in the study, told Medscape Medical News.
"However, the optimal THC-CBD ratio and potency (percent THC) for acute migraine remain to be studied. Perhaps there is an individualized dose that can be obtained by titration. We also don't know if the effect changes after repeated use," Yuan cautioned.
He also noted that cannabis use was associated with medication use headache in a retrospective study, "although the causality remains to be determined."
"While there was no serious adverse event, it is not completely risk-free, especially when cannabis is used repeatedly for a short duration. Since the physician does not have direct control over what happens at the dispensary, we need to counsel our patients more carefully when recommending cannabis/cannabinoids," Yuan said.
Overall, he said he is "cautiously optimistic about cannabis use for acute migraine."
This was an investigator-initiated study, with no commercial funding. Schuster has disclosed relationships with Schedule 1 Therapeutics, Averitas, Lundbeck, Eli Lilly, ShiraTronics, and Syneos. In the past 24 months, Yuan has served as a site investigator for Teva, AbbVie, Ipsen, Parema; received advisory/consultant fees from Salvia, Pfizer, AbbVie, Cerenovus; and royalties from Cambridge University Press and MedLink.