M. Lynch and F. Campbell. Cannabinoids for Treatment of Chronic Non-Cancer Pain; a Systematic Review of Randomized Trials. Arch Pediatr Adolesc Med: 163(7)601-7. . PMID: 21426373
This was a systematic review of eighteen randomized controlled trials (RCTs) examining cannabinoids in the treatment of chronic non-cancer pain. Cannabinoids studied included smoked cannabis, oromucosal extracts of cannabis based medicine, nabilone, dronabinol and a novel THC analogue. Chronic non-cancer pain conditions included neuropathic pain, fibromyalgia, rheumatoid arthritis, and mixed chronic pain. Fifteen of the trials that met the inclusion criteria demonstrated a significant analgesic effect of cannabinoid as compared with placebo and several reported significant improvements in sleep. There were no serious adverse effects and all were generally well tolerated, mild to moderate in severity and led to withdrawal from the studies in only a few cases. Overall there is evidence that cannabinoids are safe and modestly effective in neuropathic pain with preliminary evidence of efficacy in fibromyalgia and rheumatoid arthritis.
H. Meng, B. Johnston, M. Englesakis, D. E. Moulin and A. Bhatia. Selective Cannabinoids for Chronic Neuropathic Pain: A Systematic Review and Meta-analysis. Anesth Analg.
This was a review on randomized controlled trials that compared selective cannabinoids (dronabinol, nabilone, nabiximols) with conventional treatments (eg, pharmacotherapy, physical therapy, or a combination of these) or placebo in patients with chronic neuropathic pain. The researchers found that many of these studies did find that selective cannabinoids provide a small analgesic benefit in patients with chronic pain and the use was also associated with improvements in quality of life and sleep with no major adverse effects.
P. S. Kim and M. A. Fishman. Cannabis for Pain and Headaches: Primer. Curr Pain Headache Rep 21(4)19.
This article will review relevant literature regarding medical use of marijuana and cannabinoid pharmaceuticals with an emphasis on pain and headaches. Phytocannabinoids have been identified as key compounds involved in analgesia and anti-inflammatory effects. Other compounds found in cannabis such as flavonoids and terpenes are also being investigated individually or synergistically with other compounds of the plant.
M. A. Ware, T. Wang, S. Shapiro, A. Robinson, T. Ducruet, T. Huynh, A. Gamsa, G. J. Bennett and J. P. Collet. Smoked cannabis for chronic neuropathic pain: a randomized controlled trial. CMAJ 182(14)E694-701. PMC2950205
This study randomized 23 individuals with post-traumatic or post surgery neuropathic pain and measured the effect of cannabis on mood, sleep and quality of life, as well as adverse events. The researchers found that a single inhalation of 25 mg of 9.4% tetrahydrocannabinol herbal cannabis three times daily for five days reduced the intensity of pain, improved sleep and was well tolerated (did not have significant adverse effects).