Effects of cannabinoid administration for pain: A meta-analysis and meta-regression.

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“Chronic pain states have resulted in an overreliance on opioid pain relievers, which can carry significant risks when used long term. As such, alternative pain treatments are increasingly desired.

Although emerging research suggests that cannabinoids have therapeutic potential regarding pain, results from studies across pain populations have been inconsistent. To provide meta-analytic clarification regarding cannabis’s impact on subjective pain, we identified studies that assessed drug-induced pain modulations under cannabinoid and corresponding placebo conditions.

Results revealed that cannabinoid administration produced a medium-to-large effect across included studies, Cohen’s d = -0.58, 95% confidence interval (CI) [-0.74, -0.43], while placebo administration produced a small-to-medium effect, Cohen’s d = -0.39, 95% CI [-0.52, -0.26]. Meta-regression revealed that cannabinoids, β = -0.43, 95% CI [-0.62, -0.24], p < .05, synthetic cannabinoids, β = -0.39, 95% CI [-0.65, -0.14], p < .05, and sample size, β = 0.01, 95% CI [0.00, 0.01], p < .05, were associated with marked pain reduction.

These outcomes suggest that cannabinoid-based pharmacotherapies may serve as effective replacement/adjunctive options regarding pain, however, additional research is warranted.”

https://www.ncbi.nlm.nih.gov/pubmed/31120281

https://psycnet.apa.org/doiLanding?doi=10.1037%2Fpha0000281

CB2 receptor deletion on myeloid cells enhanced mechanical allodynia in a mouse model of neuropathic pain.

 Scientific Reports“Neuropathic pain can develop after nerve injury, leading to a chronic condition with spontaneous pain and hyperalgesia.

Pain is typically restricted to the side of the injured nerve, but may occasionally spread to the contralateral side, a condition that is often referred to as mirror-image pain.

Mechanisms leading to mirror-image pain are not completely understood, but cannabinoid CB2 receptors have been implicated.

In this study, we use genetic mouse models to address the question if CB2 receptors on neurons or on microglia/macrophages are involved.

We conclude that CB2 receptors on microglia and macrophages, but not on neurons, modulate neuropathic pain responses.”

https://www.ncbi.nlm.nih.gov/pubmed/31097758

https://www.nature.com/articles/s41598-019-43858-4

Δ9-tetrahydrocannabinol attenuates oxycodone self-administration under extended access conditions.

Neuropharmacology

“Growing nonmedical use of prescription opioids is a global problem, motivating research on ways to reduce use and combat addiction.

Medical cannabis (“medical marijuana”) legalization has been associated epidemiologically with reduced opioid harms and cannabinoids have been shown to modulate effects of opioids in animal models.

This study was conducted to determine if Δ9-tetrahydrocannabinol (THC) enhances the behavioral effects of oxycodone.

Together these data demonstrate additive effects of THC and oxycodone and suggest the potential use of THC to enhance therapeutic efficacy, and to reduce the abuse, of opioids.”

https://www.ncbi.nlm.nih.gov/pubmed/30980837

“Δ9-tetrahydrocannabinol (THC) enhances the antinociceptive effects of oxycodone. Vaporized and injected THC reduces oxycodone self-administration. Cannabinoids may reduce opioid use for analgesia. Cannabinoids may reduce nonmedical opioid use.”  

https://www.sciencedirect.com/science/article/pii/S0028390819301212?via%3Dihub

Analyzing the role of cannabinoids as modulators of Wnt/β-catenin signaling pathway for their use in the management of neuropathic pain.

Bioorganic & Medicinal Chemistry Letters

“Neuropathic pain is a debilitating form of treatment-resistant chronic pain caused by damage to the nervous system. Cannabinoids have been known for suppressing neuropathic pain by modulating the endo cannabinoid system. Since the canonical Wnt/β-catenin signaling has recently been implicated in pain sensation, we investigated the impact of major cannabinoids (1-6) from the leaves of Cannabis sativa and an epoxy derivative of compound 2, here upon referred to as 2a, on modulating Wnt/β-catenin signaling pathway. The results presented in this study show that compound 1, 2 and 2a exhibited potent inhibitory activity against Wnt/β-catenin pathway in a dose-dependent manner. Compound 2a was seen to inhibit this pathway at slightly lower concentrations than its parent molecule 2, under similar conditions. Taken together, compound 1, 2 and 2a, by virtue of their inhibition of Wnt/β-catenin signaling pathway, could be developed as effective neuroprotective agents for the management of neuropathic pain.”

https://www.ncbi.nlm.nih.gov/pubmed/30871771

https://www.sciencedirect.com/science/article/pii/S0960894X19301428?via%3Dihub

β-Caryophyllene, a Natural Sesquiterpene, Attenuates Neuropathic Pain and Depressive-Like Behavior in Experimental Diabetic Mice.

 View details for Journal of Medicinal Food cover image“Neuropathic pain (NP) is associated with chronic hyperglycemia and emotional disorders such as depression in diabetic patients, complicating the course of treatment. Drugs currently used to treat NP have undesirable side effects, so research on other natural sources has been required.

β-caryophyllene (BCP), a natural sesquiterpene found in some food condiments and considered an agonist to cannabinoid receptor type 2, could have potential therapeutic effects to treat conditions such as NP and emotional disorders. For this reason, we assessed whether BCP modulates nociception, anxiety, and depressive-like behavior in streptozotocin (STZ)-induced experimental diabetic BALB/c female mice.

BCP was orally chronic administrated (10 mg/kg/60 μL). Pain developed with STZ was evaluated with von Frey filament test, SMALGO®, and hot plate test. Anxiety and depression-like behavior were assessed by marbles test, forced swim test, and tail suspension test. BCP significantly reduced glycemia in experimental diabetic mice. The pain was also mitigated by BCP administration. Depression-like behavior assessed with tail suspension test was attenuated with orally chronic BCP administration. Substance P and cytokines such as interleukin-1β (IL-1β), tumor necrosis factor α (TNF-α), and interleukin-6 (IL-6) were also attenuated with BCP administration. NP was positively correlated with substance P and IL-6 and IL-1β release.

Our data using an orally chronic BCP administration in the STZ challenged mice to suggest that glycemia, diabetes-related NP, and depressive-like behavior could be prevented/reduced by dietary BCP.”

https://www.ncbi.nlm.nih.gov/pubmed/30864870

https://www.liebertpub.com/doi/10.1089/jmf.2018.0157

“β-caryophyllene (BCP) is a common constitute of the essential oils of numerous spice, food plants and major component in Cannabis.”   http://www.ncbi.nlm.nih.gov/pubmed/23138934

“Beta-caryophyllene is a dietary cannabinoid.”   https://www.ncbi.nlm.nih.gov/pubmed/18574142

Role of endocannabinoid system in dopamine signalling within the reward circuits affected by chronic pain.

Pharmacological Research

“The association between chronic pain, depression and anxiety has gained particular attention due to high rates of comorbidity. Recent data demonstrated that the mesolimbic reward circuitry is involved in the pathology of chronic pain. Interestingly, the mesolimbic reward circuit participates both in pain perception and in pain relief.

The endocannabinoid system (ECS) has emerged as a highly relevant player involved in both pain perception and reward processing. Targeting ECS could become a novel treatment strategy for chronic pain patients.

However, little is known about the underlying mechanisms of action of cannabinoids at the intersection of neurochemical changes in reward circuits and chronic pain. Because understanding the benefits and risks of cannabinoids is paramount, the aim of this review is to evaluate the state-of-art knowledge about the involvement of the ECS in dopamine signalling within the reward circuits affected by chronic pain.”

https://www.ncbi.nlm.nih.gov/pubmed/30831242

https://www.sciencedirect.com/science/article/abs/pii/S1043661819300088?via%3Dihub

Cannabinoids: a new approach for pain control?

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“To analyze available data related to the use of cannabinoids in medicine, with a special focus on pain management in cancer. The use of cannabis for medical purposes is growing but there are still numerous questions to be solved: effectiveness, safety, and specific indications.

RECENT FINDINGS:

There is considerable variation between countries in the approaches taken, reflecting a variety of historical and cultural factors and despite few randomized controlled studies using natural cannabinoids, there is a trend to state that the use of cannabis should be taken seriously as a potential treatment of cancer-related pain. Cannabidiol, a nontoxic phytocannabinoid with few side-effects is promising in various indications in medicine.

SUMMARY:

The endocannabinoid system is a potential therapeutic target. Cannabinoids may be considered as potential adjuvant in cancer-related pain management. Cannabidiol appears to be the drug of choice. Analgesic trial designs should evolve to get closer to real-life practice and to avoid biases.”

https://www.ncbi.nlm.nih.gov/pubmed/30789867

https://insights.ovid.com/crossref?an=00001622-900000000-00002

An Update of Current Cannabis-Based Pharmaceuticals in Pain Medicine.

 

“Cannabis users have long reported therapeutic properties of the plant for a variety of conditions, some of which include nausea, emesis, seizures, cancer, neurogenic diseases and pain control. Research has elucidated many cannabinoid pharmacodynamic and pharmacokinetic properties, expanding the potential use of cannabinoids as a medical therapy.

Due to the inconsistent delivery and control of the active components involved with smoking, pharmaceutical companies are investigating and prioritizing routes other than smoke inhalation for therapeutic use of cannabinoids. In this relatively new field of pharmaceutical development, ongoing drug development promises great benefit from targeted endocannabinoid receptor agonism.

Available in Canada and Europe, nabiximols, a specific extract from the Cannabis plant, has demonstrated great benefit in the treatment of pain related to spasticity in multiple sclerosis, cancer and otherwise chronic pain conditions.

The cannabidiol oral solution Epidiolex®, which is available in the USA, is indicated for management of refractory epilepsy but may offer therapeutic relief to chronic pain conditions as well.

Current investigative drugs, such as those developed by Cara Therapeutics and Zynerba Pharmaceuticals, are synthetic cannabinoids which show promise to specifically target neuropsychiatric conditions and chronic pain symptoms such as neuropathy and allodynia.

The objective of this review is to provide clinicians with an update of currently available and promising developmental cannabis pharmaceutical derivatives which may stand to greatly benefit patients with otherwise difficult-to-treat chronic conditions.”

https://www.ncbi.nlm.nih.gov/pubmed/30721403

https://link.springer.com/article/10.1007%2Fs40122-019-0114-4

A Cost-Effectiveness Model for Adjunctive Smoked Cannabis in the Treatment of Chronic Neuropathic Pain

View details for Cannabis and Cannabinoid Research cover image

“A recent meta-analysis affirmed the benefit of medicinal cannabis for chronic neuropathic pain, a disabling and difficult-to-treat condition. As medicinal cannabis use is becoming increasingly prevalent among Americans, an exploration of its economic feasibility is warranted. We present this cost-effectiveness analysis of adjunctive cannabis pharmacotherapy for chronic peripheral neuropathy.

A growing body of scientific literature demonstrates reproducible efficacy of cannabis in the treatment of several medical conditions, including chronic neuropathic pain. Clinical trials of oral, smoked, and vaporized cannabis and cannabinoids have all demonstrated analgesic benefit of medicinal cannabis in the treatment of this costly and disabling condition. A recent meta-analysis of individual patient data from five randomized controlled trials of inhaled cannabis demonstrated pain relief comparable to gabapentin. Treatment guidelines for neuropathic pain recommend consideration of cannabinoids as third-line agents.

As recently proposed willingness-to-pay thresholds for the United States health marketplace range from $110,000 to $300,000 per QALY, cannabis appears cost-effective when augmenting second-line treatment for painful neuropathy. Further research is warranted to explore the long-term benefit of smoked cannabis and standardization of its dosing for chronic neuropathic pain.”

https://www.ncbi.nlm.nih.gov/pubmed/30944870

https://www.liebertpub.com/doi/10.1089/can.2018.0027

“New study analyzes cost effectiveness of smoked cannabis to treat chronic neuropathic pain” https://www.eurekalert.org/pub_releases/2019-01/mali-nsa012919.php

Dark Classics in Chemical Neuroscience: Δ9-Tetrahydrocannabinol.

 ACS Chemical Neuroscience

“Cannabis (Cannabis sativa) is the most widely used illicit drug in the world, with an estimated 192 million users globally.

The main psychoactive component of cannabis is (-)-trans-Δ9-tetrahydrocannabinol (Δ9-THC), a molecule with a diverse range of pharmacological actions. The unique and distinctive intoxication caused by Δ9-THC primarily reflects partial agonist action at central cannabinoid type 1 (CB1) receptors.

Δ9-THC is an approved therapeutic treatment for a range of conditions, including chronic pain, chemotherapy-induced nausea and vomiting, and is being investigated in indications such as anorexia nervosa, agitation in dementia, and Tourette’s syndrome.

It is available as a regulated pharmaceutical in products such as Marinol®, Sativex®, and Namisol®, as well as in an ever-increasing range of unregistered medicinal and recreational cannabis products.

While cannabis is an ancient medicament, contemporary use is embroiled in legal, scientific, and social controversy, much of which relates to the potential hazards and benefits of Δ9-THC itself.

Robust contemporary debate surrounds the therapeutic value of Δ9-THC in different diseases, its capacity to produce psychosis and cognitive impairment, and the addictive and “gateway” potential of the drug.

This review will provide a profile of the chemistry, pharmacology, toxicology, and recreational and therapeutic uses of Δ9-THC, as well as the historical and societal importance of this unique, distinctive, and ubiquitous psychoactive substance.”

https://www.ncbi.nlm.nih.gov/pubmed/30689342

https://pubs.acs.org/doi/10.1021/acschemneuro.8b00651