Analgesic

An analgesic relieves pain without producing anesthesia. Cannabinoid analgesia is mediated chiefly by CB1 receptors on peripheral nociceptors, dorsal-root ganglia, and spinal/supraspinal sites involved in descending inhibitory pain pathways (periaqueductal gray, rostral ventromedial medulla), with additional contributions from CB2 receptors on immune cells modulating neurogenic inflammation. NASEM 2017 concluded there is substantial evidence that cannabis is effective for the treatment of chronic pain in adults, drawing heavily on the Whiting et al. (2015, JAMA) meta-analysis. Evidence is strongest for neuropathic pain and pain associated with multiple sclerosis. The Cochrane review by Mücke et al. (2018) found that cannabis-based medicines produced modest increases in ≥30% pain relief and Patient Global Impression of Change versus placebo in chronic neuropathic pain, but with increased nervous-system and psychiatric adverse events, yielding low-to-moderate GRADE certainty. → See also: CB1 Receptor, CB2 Receptor, Nabiximols.