Efficiency of cannabis and cannabidiol in managing chronic pain syndromes: A comprehensive narrative review

Chronic pain affects up to 40% of adults, contributing to high medical expenses, the loss of productivity, reduced quality of life (QoL), and disability. Chronic pain requires detailed diagnostic assessment, treatment and rehabilitation, yet approx. 80% of patients report inadequate pain management. As new treatment options are needed, we aimed to explore the effectiveness of medical cannabis-based products in managing chronic pain, with a particular focus on treatment patterns. We searched the PubMed, Scopus and Web of Science databases using keywords related to cannabinoids and chronic pain syndromes. In total, 3,954 articles were identified, and 74 studies involving 12,562 patients were included. The effectiveness of cannabis-based products varied across studies. Cannabinoids were most effective in treating chronic secondary headache and orofacial pain, chronic secondary musculoskeletal pain, chronic secondary visceral pain, and chronic neuropathic pain. Properly qualifying patients is the first crucial step in managing chronic pain, considering pain characteristics, comorbidities and other treatment options. Treatment should start with low doses of cannabinoids, which are then increased to achieve the desired therapeutic effect while minimizing adverse effects. This narrative review revealed significant gaps in the evidence regarding precise treatment patterns, particularly for the long-term maintenance treatment needed by patients with chronic pain. Medical cannabis can be considered an option for carefully selected patients with chronic pain syndromes when other treatment options fail to achieve an adequate response, and when the potential benefits outweigh the risks. However, there is still a need for well-designed clinical research to establish the long-term efficacy and safety of cannabinoids.