“The management of chronic pain is a complex challenge worldwide. Cannabis-based medicines (CBMs) have proven to be efficient in reducing chronic pain, although the topic remains highly controversial in this field.
This study’s aim is to conduct a conclusive review and meta-analysis, which incorporates all randomized controlled trials (RCTs) in order to update clinicians’ and researchers’ knowledge regarding the efficacy and adverse events (AEs) of CBMs for chronic and postoperative pain treatment.
The current systematic review suggests that CBMs might be effective for chronic pain treatment, based on limited evidence, primarily for neuropathic pain (NP) patients. Additionally, GI AEs occurred more frequently when CBMs were administered via oral/oromucosal routes than by inhalation.”
“Osteoarthritis (OA) is a multifactorial joint disease, which includes joint degeneration, intermittent inflammation, and peripheral neuropathy. Cannabidiol (CBD) is a non-euphoria producing constituent of cannabis that has the potential to relieve pain.
The aim of this study was to determine if CBD is anti-nociceptive in OA, and whether inhibition of inflammation by CBD could prevent the development of OA pain and joint neuropathy.
The therapeutic and prophylactic effects of peripheral CBD (100-300μg) were assessed. In end stage OA, CBD dose-dependently decreased joint afferent firing rate, and increased withdrawal threshold and weight bearing (p<0.0001; n=8). Acute, transient joint inflammation was reduced by local CBD treatment (p<0.0001; n=6). Prophylactic administration of CBD prevented the development of MIA-induced joint pain at later time points (p<0.0001; n=8), and was also found to be neuroprotective (p<0.05; n=6-8).
The data presented here indicate that local administration of CBD blocked OA pain. Prophylactic CBD treatment prevented the later development of pain and nerve damage in these OA joints.
These findings suggest that CBD may be a safe, useful therapeutic for treating OA joint neuropathic pain.”
“A great need exists for the development of new medications to treat pain resulting from various disease states and types of injury. Given that the endogenous cannabinoid (ie, endocannabinoid) system modulates neuronal and immune cell function, both of which play key roles in pain, therapeutics targeting this system hold promise as novel analgesics.
Potential therapeutic targets include the cannabinoid receptors, type 1 and 2, as well as biosynthetic and catabolic enzymes of the endocannabinoids N-arachidonoylethanolamine and 2-arachidonoylglycerol. Notably, cannabinoid receptor agonists as well as inhibitors of endocannabinoid-regulating enzymes fatty acid amide hydrolase and monoacylglycerol lipase produce reliable antinociceptive effects, and offer opioid-sparing antinociceptive effects in myriad preclinical inflammatory and neuropathic pain models.
Emerging clinical studies show that ‘medicinal’ cannabis or cannabinoid-based medications relieve pain in human diseases, such as cancer, multiple sclerosis, and fibromyalgia.
Here, we examine the preclinical and clinical evidence of various endocannabinoid system targets as potential therapeutic strategies for inflammatory and neuropathic pain conditions.”
“The endocannabinoid system is thought to modulate nociceptive signaling making it a potential therapeutic target for treating pain.
However, there is evidence that endocannabinoids have both pro- and anti-nociceptive effects. In previous studies using Hirudo verbana (the medicinal leech), endocannabinoids were found to depress nociceptive synapses, but enhance non-nociceptive synapses. Here we examined whether endocannabinoids have similar bidirectional effects on behavioral responses to nociceptive vs. non-nociceptive stimuli in vivo.
These results provide evidence that endocannabinoids can have opposing effects on nociceptive vs. non-nociceptive pathways and suggest that cannabinoid-based therapies may be more appropriate for treating pain disorders in which hyperalgesia and not allodynia is the primary symptom.”
“This study investigated whether intramuscular injection of delta-9-tetrahydrocannabinol (THC), by acting on peripheral cannabinoid (CB) receptors, could decrease nerve growth factor (NGF)-induced sensitization in female rat masseter muscle; a model which mimics the symptoms of myofascial temporomandibular disorders.
It was found that CB1 and CB2 receptors are expressed by trigeminal ganglion neurons that innervate the masseter muscle and also on their peripheral endings.
These results suggest that reduced inhibitory input from the peripheral cannabinoid system may contribute to NGF-induced local myofascial sensitization of mechanoreceptors. Peripheral application of THC may counter this effect by activating the CB1 receptors on masseter muscle mechanoreceptors to provide analgesic relief without central side effects.
Our results suggest THC could reduce masticatory muscle pain through activating peripheral CB1 receptors. Peripheral application of cannabinoids could be a novel approach to provide analgesic relief without central side effects.”
“Cannabidiol (CBD) is a phytocannabinoid with multiple pharmacological effects and several potential therapeutic properties. Its low oral bioavailability, however, can limit its clinical use.
Preliminary results indicate that fluorination of the CBD molecule increases its pharmacological potency. Here, we investigated whether HUF-101 (3, 10, and 30mg/kg), a fluorinated CBD analogue, would induce antinociceptive effects.
These findings show that HUF-101 produced antinociceptive effects at lower doses than CBD, indicating that the addition of fluoride improved its pharmacological profile. Furthermore, some of the antinociceptive effects of CBD and HUF-101 effects seem to involve the activation of CB1 and CB2 receptors.”
“Complementary and alternative medicine (CAM) therapies may be used as a non-pharmacological approach to chronic pain management. Twenty-six reviews (207 clinical trials, >12,000 participants) about 18 CAM modalities, falling under natural products, mind and body practices or other complementary health approaches were included. Inhaled cannabis, graded motor imagery, and Compound Kushen injection (a form of Chinese medicine) were found the most efficient and tolerable for chronic pain relief. When reported, adverse effects related to these CAM were minor.” https://www.ncbi.nlm.nih.gov/pubmed/28669581
“Prescription drug overdoses are the leading cause of accidental death in the United States. Alternatives to opioids for the treatment of pain are necessary to address this issue. Cannabis can be an effective treatment for pain, greatly reduces the chance of dependence, and eliminates the risk of fatal overdose compared to opioid-based medications. Medical cannabis patients report that cannabis is just as effective, if not more, than opioid-based medications for pain.
The results of this study provide implications from both a micro and macro level. First, from the macro level, there have been three previously published indicators of public health changes in states that permit medical cannabis: decreases in opioid related mortality, decreases in spending on opioids, and a decrease in traffic fatalities. While none of these studies shows a cause and effect relationship, they do suggest public health related population based changes in localities where cannabis can be accessed to treat pain. Given that the participants in this study reported a greater likelihood of using cannabis as a substitute in a less stigmatized and easily accessible environment, it makes sense why we would see these changes in locations where medical cannabis is sanctioned versus places where it is illegal.
At the micro level, there is a great deal of individual risk associated with prolonged use of opioids and perhaps even nonopioid-based pain medications. The prescribing of opioids has not been curbed in the United States, despite the growing number of fatal overdoses and reported dependence. Providing the patient with the option of cannabis as a method of pain treatment alongside the option of opioids might assist with pain relief in a safer environment with less risk. A society with less opioid dependent people will result in fewer public health harms.”
“In animal studies, four times less morphine and ten times less codeine was needed when cannabinoids were given at the same time.
The higher the dose of opioid pain relievers, the more likely it is a patient will experience side effects and complications. With the opioid epidemic becoming a pressing problem, researchers are working to find ways to provide pain relief with less risk. To understand whether therapeutic cannabinoids could be an effective strategy to reduce opioid use, researchers at the University of New South Wales and the Centre for Addiction and Mental Health analysed data from 19 pre-clinical studies and nine clinical trials.
“These studies highlight the potential beneficial effects of combining opioids and cannabinoids””
“Chronic pain states are highly prevalent and yet poorly controlled by currently available analgesics, representing an enormous clinical, societal, and economic burden. Existing pain medications have significant limitations and adverse effects including tolerance, dependence, gastrointestinal dysfunction, cognitive impairment, and a narrow therapeutic window, making the search for novel analgesics ever more important. In this article, we review the role of an important endogenous pain control system, the endocannabinoid (EC) system, in the sensory, emotional, and cognitive aspects of pain. Herein, we briefly cover the discovery of the EC system and its role in pain processing pathways, before concentrating on three areas of current major interest in EC pain research; 1. Pharmacological enhancement of endocannabinoid activity (via blockade of EC metabolism or allosteric modulation of CB1receptors); 2. The EC System and stress-induced modulation of pain; and 3. The EC system & medial prefrontal cortex (mPFC) dysfunction in pain states. Whilst we focus predominantly on the preclinical data, we also include extensive discussion of recent clinical failures of endocannabinoid-related therapies, the future potential of these approaches, and important directions for future research on the EC system and pain.”