Chronic neuropathic pain is a prevalent condition that places a heavy burden on individuals and the healthcare system. Current medications have limitations and new approaches are needed, particularly given the current opioid crisis. This animal data suggests that cannabidiol and low dose nabiximols warrant consideration for clinical studies, at least as adjuvants to current drugs. Preclinical research is also required to identify other phytocannabinoids that have therapeutic potential.
Recent advances have dramatically increased our understanding of cannabinoid pharmacology: the psychoactive constituents of Cannabis sativa have been isolated, synthetic cannabinoids described and an endocannabinoid system identified, together with its component receptors, ligands and their biochemistry. Strong laboratory evidence now underwrites anecdotal claims of cannabinoid analgesia in inflammatory and neuropathic pain.
The endocannabinoid system (ECS) controls a large number of vital functions. Suboptimal tone of the ECS in certain regions of the nervous system may be associated with disorders that are also associated with pain. Pain and inflammation processes can be modulated by the exogenous supply of cannabinoids. Low-to-moderate pain-relieving effects and in individual cases large pain-relieving effects were observed in randomized, controlled studies of various types of chronic pain.
Many cultures throughout history have used cannabis to treat a variety of painful ailments. Neuropathic pain is a complicated condition that is challenging to treat with our current medications. Recent scientific discovery has elucidated the intricate role of the endocannabinoid system in the pathophysiology of neuropathic pain. As societal perceptions change, and legislation on medical cannabis relaxes, there is growing interest in the use of medical cannabis for neuropathic pain. The results suggest medical cannabis may be as tolerable and effective as current neuropathic agents; however, more studies are needed to determine the long-term effects of medical cannabis use. Furthermore, continued research to optimize dosing, cannabinoid ratios, and alternate routes of administration may help to refine the therapeutic role of medical cannabis for neuropathic pain.
When a patient’s neuropathic symptoms are manifested in the form of physical pain, the result is considered “chronic pain.” Neuropathy and neuropathic pain have no cure. In fact, modern day medical research into these disorders exists to better the lives of those patients suffering from these afflictions. Nevertheless, doctors and patients are looking at medical marijuana as non-addictive.
Cannabinoids appear to possess many potential medical uses, which may extend to pain control. A narrative review of the literature has found a variety of studies testing botanical and synthetic cannabinoids in different pain syndromes (acute pain, cancer pain, chronic noncancer pain, fibromyalgia pain, migraine, neuropathic pain, visceral pain, and others). Results from these studies are mixed; cannabinoids appear to be most effective in controlling neuropathic pain, allodynia, medication-rebound headache, and chronic noncancer pain. A great deal more remains to be elucidated about cannabinoids which may emerge to play an important role in the treatment of neuropathic and possibly other painful conditions. There remains a great deal more to learn about the role of cannabinoids in pain management.