Medical Cannabis for Headache Pain: a Primer for Clinicians

Purpose of Review: Public acceptance of Cannabis sativa L. (cannabis) as a therapeutic option grows despite lags in both research and clinician familiarity. Cannabis—whether as a medical, recreational, or illicit substance—is and has been commonly used by patients. With ongoing decriminalization efforts, decreased perception of harms, and increased use of cannabis in the treatment of symptoms and disease, it is critical for clinicians to understand the rationale for specific therapies and their medical and practical implications for patients. In view of the opioid crisis, overall patient dissatisfaction, and lack of adherence to current chronic pain and headache therapies, this review provides up-to-date knowledge on cannabis as a potential treatment option for headache pain. Recent Findings: Research into the use of cannabinoids for disease treatment have led to FDA-approved drugs for seizures, nausea, and vomiting caused by cancer chemotherapy; and for decreased appetite and weight loss in people with HIV/AIDS. For a wide variety of conditions and symptoms (including chronic pain), cannabis has gained increasing acceptance in society. The effects of cannabidiol (CBD) and tetrahydrocannabinol (THC) in pain pathways have been significantly elucidated. An increasing number of retrospective studies have shown a decrease in pain scores after administration of cannabinoids, as well as long-term benefits such as reduced opiate use. Yet, there is no FDA-approved cannabis product for headache or other chronic pain disorders. More is being done to determine who is likely to benefit from cannabis as well as to understand the long-term effects and limitations of the treatment. Summary: Cannabis can refer to a number of products derived from the plant Cannabis sativa L. Relatively well-tolerated, these products come in different configurations, types, and delivery forms. Specific formulations of the plant have been shown to be an effective treatment modality for chronic pain, including headache. It is important for clinicians to know which product is being discussed as well as the harms, benefits, contraindications, interactions, and unknowns in order to provide the best counsel for patients.