Oral cannabinoid preparations for the treatment of chronic migraine: a retrospective study.

Objective: To explore the effectiveness and safety of 3 oral cannabinoid preparations (FM2®, Bedrocan® and Bediol®) in the treatment of chronic migraine. Design: Retrospective, cohort study. Subjects: Patients with chronic migraine who received FM2®, Bedrocan® or Bediol® daily for the off-label treatment of their headache, up to 6 months. Methods: The number of migraine days per month, pain intensity, the number of acute medications taken per month, the number of days per month when the patient took at least one acute medication, and adverse events were recorded at baseline, 3 months, and 6 months after the start of treatment with oral cannabinoid preparations. Results: The number of migraine days didn't change significantly after the 3rd and the 6th month when compared to baseline (P = 0.1182). The pain intensity (P = 0.0004), the acute medication consumption (P = 0.0006) and the number of days per month in which patients took, at least, one acute medication, (P = 0.0004) significantly decreased when compared to the baseline. No significant differences were found between patients who were still taking a preventive treatment for chronic migraine and those who weren't (all P > 0.05). Different oral cannabinoid preparations displayed similar effectiveness (all P > 0.05). The AEs were mostly mild and occurred in the 43.75% of patients. Conclusions: Oral cannabinoid preparations may have a role in reducing pain intensity and acute medication intake in patients with chronic migraine, but the magnitude of the effect seems modest; further studies are needed.