“Cannabis has been shown to be beneficial in the treatment of pain and inflammatory diseases.
The biological effect of cannabis is mainly attributed to two major cannabinoids, tetrahydrocannabinol and cannabidiol. In the majority of studies to-date, a purified tetrahydrocannabinol and cannabidiol alone or in combination have been extensively examined in many studies for the treatment of numerous disorders including pain and inflammation. However, few studies have investigated the biological benefits of full-spectrum cannabis plant extract.
Given that cannabis is known to generate a large number of cannabinoids along with numerous other biologically relevant products including terpenes, studies involving purified tetrahydrocannabinol and/or cannabidiol may not precisely consider the potential biological benefits of the full-spectrum cannabis extracts. This may be especially true in the role of cannabis as a treatment of pain and inflammation. Herein, we review the pre-clinical physiological and molecular mechanisms in biological systems that are affected by cannabis.”
“Full-spectrum cannabis extract demonstrates several convincing beneficial anti-inflammatory and analgesic effects in preclinical studies. Full-spectrum cannabis extract may represent a promising therapeutic agent that seems to benefit a variety of conditions associated with pain and inflammation.”
“There is growing interest in using cannabinoids for chronic pain.
We performed a systematic review and meta-analysis of randomized controlled trials to evaluate the analgesic efficacy and adverse effects of cannabinoids for chronic non-cancer pain.
PubMed, EMBASE, Web of Science, Cochrane CENTRAL and clinicaltrials.gov were searched up to December 2018. Information on the type, dosage, route of administration, pain conditions, pain scores, and adverse events were extracted for qualitative analysis. Meta-analysis of analgesic efficacy was performed. Meta-regression was performed to compare the analgesic efficacy for different pain conditions (neuropathic versus non-neuropathic pain). Risk of bias was assessed by The Cochrane Risk of Bias tool, and the strength of the evidence was assessed using the Grade of Recommendations Assessment, Development, and Evaluation (GRADE) approach.
Forty-three randomized controlled trials were included. Meta-analysis was performed for 33 studies that compared cannabinoids to placebo, and showed a mean pain score (scale 0-10) reduction of -0.70 (p < 0.001, random effect). Meta-regression showed that analgesic efficacy was similar for neuropathic and non-neuropathic pain (Difference = -0.14, p = 0.262).
Inhaled, oral, and oromucosal administration all provided statistically significant, but small reduction in mean pain score (-0.97, -0.85, -0.45, all p < 0.001). Incidence of serious adverse events was rare, and non-serious adverse events were usually mild to moderate. Heterogeneity was moderate.
The GRADE level of evidence was low to moderate. Pain intensity of chronic non-cancer patients was reduced by cannabinoids consumption, but effect sizes were small. Efficacy for neuropathic and non-neuropathic pain was similar.”
“Opioid receptor agonist drugs, such as morphine, are very effective for treating chronic and severe pain; but, tolerance can develop with long-term use. Although there is a lot of information about the pathophysiological mechanisms of opioid tolerance, it is still not fully clarified. Suggested mechanisms for opioid tolerance include opioid receptor desensitisation, reduction of sensitivity G-proteins, activation of mitogen-activated protein kinase (MAPK), altered intracellular signaling pathway including nitric oxide, and activation of mammalian target of rapamycin (mTOR).
One way to reduce opioid tolerance and increase the analgesic potential is to use low doses. Combination of cannabinoids with opioids has been shown to manifest reduce the opioid dose. Experimental studies revealed an interaction of the endocannabinoid system and opioid antinociception.
Cannabinoid and opioid receptor systems use common pathways in the formation of analgesic effect and demonstrate their activity via G protein coupled receptors (GPCR). Cannabinoid drugs modulate opioid analgesic activity at a number of distinct levels within the cell, ranging from direct receptor associations, to post-receptor interactions through shared signal transduction pathways.
This review summarizes the data indicating that with combining cannabinoids and opioids drugs may be able to produce long-term analgesic effects, while preventing the opioid analgesic tolerance.”
“Chronic pain is the most common reason reported for using medical cannabis.
The goal of this research was to determine if the two primary phytocannabinoids, THC and CBD, are effective treatments for persistent inflammatory pain.
These results suggest that THC may be more beneficial than CBD for reducing inflammatory pain, in that THC maintains its efficacy with short-term treatment in both sexes, and does not induce immune activation.
SIGNIFICANCE STATEMENT: CBDs and THCs pain-relieving effects are examined in male and female rats with persistent inflammatory pain to determine if individual phytocannabinoids could be a viable treatment for men and women with chronic inflammatory pain. Additionally, sex differences in the immune response to an adjuvant and to THC and CBD are characterized to provided preliminary insight into immune-related effects of cannabinoid-based therapy for pain.”
“The global cancer burden is significantly increasing at an alarming rate affecting patients, relatives, communities, and health-care system. Cancer patients require adequate pain relief and palliative care throughout the life course, especially in terminal illness. Although opioid treatment is successful in majority of patients, around 40% do not achieve enough analgesia or are prone to serious side effects and toxicity. The treatment of medical conditions with cannabis and cannabinoid compounds is constantly expanding. This review organizes the current knowledge in the context of SNPs associated with opioids and nonopioids and its clinical consequences in pain management and pharmacogenetic targets of cannabinoids, for use in clinical practice.”
“For patients with chronic, non-cancer pain, traditional pain-relieving medications include opioids, which have shown benefits but are associated with increased risks of addiction and adverse effects.
Medical cannabis has emerged as a treatment alternative for managing these patients and there has been a rise in the number of randomized clinical trials in recent years; therefore, a systematic review of the evidence was warranted.
Thirty-six trials (4006 participants) were included, examining smoked cannabis (4 trials), oromucosal cannabis sprays (14 trials), and oral cannabinoids (18 trials). Compared with placebo, cannabinoids showed a significant reduction in pain which was greatest with treatment duration of 2 to 8 weeks (weighted mean difference on a 0-10 pain visual analogue scale -0.68, 95% confidence interval [CI], -0.96 to -0.40, I2 = 8%, P < .00001; n = 16 trials). When stratified by route of administration, pain condition, and type of cannabinoids, oral cannabinoids had a larger reduction in pain compared with placebo relative to oromucosal and smoked formulations but the difference was not significant (P[interaction] > .05 in all the 3 durations of treatment); cannabinoids had a smaller reduction in pain due to multiple sclerosis compared with placebo relative to other neuropathic pain (P[interaction] = .05) within 2 weeks and the difference was not significant relative to pain due to rheumatic arthritis; nabilone had a greater reduction in pain compared with placebo relative to other types of cannabinoids longer than 2 weeks of treatment but the difference was not significant (P[interaction] > .05). Serious AEs were rare, and similar across the cannabinoid (74 out of 2176, 3.4%) and placebo groups (53 out of 1640, 3.2%). There was an increased risk of non-serious AEs with cannabinoids compared with placebo.
There was moderate evidence to support cannabinoids in treating chronic, non-cancer pain at 2 weeks. Similar results were observed at later time points, but the confidence in effect is low. There is little evidence that cannabinoids increase the risk of experiencing serious AEs, although non-serious AEs may be common in the short-term period following use.”
“The 20% prevalence of chronic pain in the general population is a major health concern given the often profound associated impairment of daily activities, employment status, and health-related quality of life in sufferers. Resource utilization associated with chronic pain represents an enormous burden for healthcare systems. Although analgesia based on the World Health Organization’s pain ladder continues to be the mainstay of chronic pain management, aside from chronic cancer pain or end-of-life care, prolonged use of non-steroidal anti-inflammatory drugs or opioids to manage chronic pain is rarely sustainable.
As the endocannabinoid system is known to control pain at peripheral, spinal, and supraspinal levels, interest in medical use of cannabis is growing.
A proprietary blend of cannabis plant extracts containing delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) as the principal cannabinoids is formulated as an oromucosal spray (USAN name: nabiximols) and standardized to ensure quality, consistency and stability. This review examines evidence for THC:CBD oromucosal spray (nabiximols) in the management of chronic pain conditions.
Cumulative evidence from clinical trials and an exploratory analysis of the German Pain e-Registry suggests that add-on THC:CBD oromucosal spray (nabiximols) may have a role in managing chronic neuropathic pain, although further precise clinical trials are required to draw definitive conclusions.”
“Marijuana is increasingly utilized for the treatment of multiple medical problems, including back pain, in the United States. Although there is strong preclinical evidence supporting the promise of cannabinoids in the treatment of back pain, there is a paucity of clinical data supporting their use in clinical practice. Opioids are an important medication for the treatment of acute and chronic back pain, but utilization of opioid-based regimens have likely contributed to the growing opioid epidemic. The significant risk of morbidity, mortality, and dependence secondary to opioid medications have increased the interest in nonopioid medications, including cannabinoid-based pain regimens, in treating back pain. This review will provide an overview on the pharmacology, drug delivery methods, clinical evidence, and safety considerations critical to understanding the potential role of cannabinoids in the treatment of back pain.”
“Neuropathic pain conditions including neuropathic orofacial pain (NOP) are difficult to treat. Contemporary therapeutic agents for neuropathic pain are often ineffective in relieving pain and are associated with various adverse effects. Finding new options for treating neuropathic pain is a major priority in pain-related research.
Cannabinoid-based therapeutic strategies have emerged as promising new options.
Cannabinoids mainly act on cannabinoid 1 (CB1) and 2 (CB2) receptors, and the former is widely distributed in the brain. The therapeutic significance of cannabinoids is masked by their adverse effects including sedation, motor impairment, addiction and cognitive impairment, which are thought to be mediated by CB1 receptors in the brain. Alternative approaches have been developed to overcome this problem by selectively targeting CB2 receptors, peripherally restricted CB1 receptors and endocannabinoids that may be locally synthesized on demand at sites where their actions are pertinent.
Many preclinical studies have reported that these strategies are effective for treating neuropathic pain and produce no or minimal side effects.
Recently, we observed that inhibition of degradation of a major endocannabinoid, 2-arachydonoylglycerol, can attenuate NOP following trigeminal nerve injury in mice. This review will discuss the above-mentioned alternative approaches that show potential for treating neuropathic pain including NOP.”