Pain is not a disease but a symptom felt by individuals who are experiencing something uncomfortable, either real or perceived. The uncomfortableness may be due to a multiplicity of factors including:
- Stimulation of nerve fibers in the periphery due to injury, i.e., cuts, incisions, tears, etc. (Nocioceptic Pain)
- Damage to nerve fibers in the periphery, spinal cord, or brain. (Neuropathic Pain)
- Release of chemicals from inflammation that stimulate nerves as pain (Inflammatory Pain)
- The brain’s learned response that certain movements, stimulations, or situations lead to pain so one feels pain before damage is done. (A type of Neuropathic Pain called allodynia)
- The feeling of pain in an amputated limb. (A type of Neuropathic Pain called Phantom Pain)
- Pain caused from emotional, mental, or behavioral factors, i.e., headache, stomach ache, etc. (Psychogenic Pain)
- Pain secondary to cancer and or cancer therapy.
- Chronic Pain often involves a combination of several of the above.
Pain can be classified many ways and the above list should just be considered an example. In all cases of pain, the concept of perception is foremost. Therefore, the feeling of pain is not just the stimulation of nerves but the brain’s perception of the stimulation. This is so important because in stressful situations when someone is physically hurt, pain may not be perceived until the stress of the situation is resolved, i.e., injuries in sports or war. In non-stressful situations, the amount of injury to produce the feeling of pain is often very similar from one individual to another, however, the perception of the intensity of the pain and the person’s ability to function with the pain can vary greatly. CBD-enriched hemp oil has been shown to effect many of the physiologic and psychologic changes that occur with different types of pain. With some types of pain in certain individuals, CBD-enriched hemp oil is adequate to control the pain perception and with other types of pain or individuals, it may only be helpful and require other medications to control the perception. The following research explanations are generalized descriptions. For more detailed analysis of the research on any particular time of pain, go to the disease list and find that particular subject, i.e, Pain-Neurologic, or Pain-Inflammatory, etc.
Pain is a complex experience produced by a unique combination of nerve cells that integrates the cognitive-evaluative, sensory-discriminative, and motivational-affective components that are located in different sections of the brain.1 Clinically, the sensation of pain can be treated by reducing the sensory input as well as by manipulating affective-motivational and cognitive factors as well as blocking the local causes of the pain.1 If the anterior cingulate cortex (ACC), a specific area of the brain associated with pain processing, is disconnected from the rest of the brain, the patient will still be able to localize the pain, but the pain does not bother the patient.1 CBD has been shown in both animals and in humans (via MRI studies) to effectively do the same thing.1 Other studies have found that CBD works in the brain in a manner similar to that of morphine.2,3 In addition, CBD changes the way our brain reacts to expected pain by changing how we remember painful events and reducing the anxiety associated with learned pain.4,5 This data suggests that CBD is useful in pain management by disassociating the perception of pain from the stimulus of pain.
Disassociation is not the only mechanism by which CBD assists with pain management. CBD blocks nocioceptive pain in rodents but not so much in humans, however, it does change the perception of nocioceptive pain in humans.6 CBD is anti-inflammatory which, as the inflammatory process lessens, the pain lessens.7-9 Diabetic neuropathic pain is prevented and reversed with CBD, probably due to its effect in preventing the release of inflammation cytokines in the spinal cord.10,11 Cannabinoids have been found to significantly reduce neuropathic pain and help with the pain-related morbidities of sleep and quality of their symptoms.12-14 Cannabinoids have been shown to be helpful adjuvants in patients with chronic pain and with cancer-associated pain, especially in those patients who are not controlled on usual pain medications or are having to increase their pain medications repetitively.15-19 However, when using products with significant amounts of THC, their effectiveness in reducing pain is often outweighed by their adverse side effects.16,20,21
Cannabinoids, including CBD, are helpful in some types of pain but not so helpful in others. The side effects of THC limit the effectiveness in pain control of cannabinoids containing significant amounts of this compound. Most studies of pain have been performed using cannabinoids with significant amounts of THC. However, the limited studies of CBD and CBD-enriched hemp oil in pain have yielded encouraging results in both pain perception and the elimination of the stimuli of pain. However, at this time the FDA has not approved CBD or CBD enriched hemp oil for the management of pain.
- Fuchs P, etal. The anterior cingulate cortex and pain processing. Frontiers Integrative Neuroscience 2014; 8:35.
- Laun AS, etal. GPR3, GPR6, and GPR12 as novel molecular targets: their biological functions and interaction with cannabidiol. Acta Pharmacol Sin. 2018 Jun 25.
- Ruiz-Medina J, etal. GPR3 orphan receptor is involved in neuropathic pain after peripheral nerve injury and regulates morphine-induced antinociception. 2011 Jul-Aug;61(1-2):43-50.
- Bitencourt R, Takahashi R. Cannabidiol as a therapeutic alternative for post-traumatic stress disorder: From bench research to confirmation in human trials. Frontiers Neuroscience 2018; 12:502
- Jurkus R, etal. Cannabidiol regulation of learned fear: Implication for treating anxiety-related disorders. Frontiers Pharm 2016;7:454.
- Lötsch J, etal. Current evidence of cannabinoid-based analgesia obtained in preclinical and human experimental settings. Eur J Pain. 2018 Mar;22(3):471-484.
- Brunstein S. Cannabidiol (CBD) and its analogs: A review of their effects on inflammation. Bioorg. Med. Chem. (2015), http://dx.doi.org/10.1016/j.bmc.2015.01.059
- Xiong W, etal. Cannabinoids suppress inflammatory and neuropathic pain by targeting alpha-3 glycine receptors. Exp. Med. Vol. 209 No. 6 1121-1134
- Costa B, etal. The non-psychoactive cannabis constituent cannabidiol is an orally effective therapeutic agent in rat chronic inflammatory and neuropathic pain. Eur J Pharmacol; 2007; 5:556(1-3):75-83
- Toth C, etal. Cannabinoid-mediated modulation of neuropathic pain and microglial accumulation in a model of murine type I diabetic peripheral neuropathic pain. Molecular Pain 2010; 6:16.
- Wang D, et al. Activated microglia in the spinal cord underlies diabetic neuropathic pain. Eur J Pharmacol. 2014 Apr 5;728:59-66.
- Lynch M, Campbell R. Cannabinoids for treatment of chronic non-cancer pain; a systematic review of randomized trials. Br J Clin Pharm 2011;72(5):735-44.
- Meng H, etal. Selective Cannabinoids for Chronic Neuropathic Pain: A Systematic Review and Meta-analysis. Anesth Analg. 2017 Nov;125(5):1638-1652.
- Serpell M. et al. A double-blind, randomized, placebo-controlled, parallel group study of THC/CBD spray in peripheral neuropathic pain treatment Eur J Pain. 2014 Aug;18(7):999-1012
- Hoggart B, et al. A multicentre, open-label, follow-on study to assess the long-term maintenance of effect, tolerance and safety of THC/CBD oromucosal spray in the management of neuropathic pain J Neurol. 2015 Jan;262(1):27-40.
- Kazantzis NP, etal. Opioid and cannabinoid synergy in a mouse neuropathic pain model. Br J Pharmacol 2016;173(16):2521-31.
- Darkovska-Serafimovska M, etal. Pharmacotherapeutic considerations for use of cannabinoids to relieve pain in patients with malignant diseases. J Pain Res 2018;11:837-47.
- Fallon M, etal. Sativex oromucosal spray as adjunctive therapy in advanced cancer patients with chronic pain unalleviated by optimized opioid therapy: two double-blind, randomized, placebo—controlled phase 3 studies. Br. J Pain 2017;11(3):119-33.
- Boychuk DG, etal. The effectiveness of cannabinoids in the management of chronic nonmalignant neuropathic pain: a systematic review. J Oral Facial Pain Headache 2015;29(1);7-14.
- Casey S, Vaughan C. Plant-based cannabinoids for he treatment of chronic neuropathic pain. Medicines 2018;5;67.
- Kahan M, etal. Prescribing smoked cannabis for chronic noncancer pain. Can Fam Physician 2014;60:1083-90.