Category Archives: Pain

Single and combined effects of delta9 -tetrahydrocannabinol and cannabidiol in a mouse model of chemotherapy-induced neuropathic pain.

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British Journal of Pharmacology

“It has been suggested that the non-psychoactive phytocannabinoid cannabidiol (CBD) can impact the pharmacological effects of delta-9-tetrahydrocannabinol (THC). We tested the hypothesis that CBD and THC would significantly mitigate mechanical sensitivity in a mouse model of paclitaxel-induced neuropathic pain, and that CBD+THC combinations would produce synergistic effects. We also tested the hypothesis that CBD would attenuate oxaliplatin- and vincristine- induced mechanical sensitivity.

KEY RESULTS:

Both CBD and THC alone attenuated mechanical allodynia in mice treated with paclitaxel. Very low ineffective doses of CBD and THC were synergistic when given in combination. CBD also attenuated oxaliplatin- but not vincristine-induced mechanical sensitivity, while THC significantly attenuated vincristine- but not oxaliplatin-induced mechanical sensitivity. The low dose combination significantly attenuated oxaliplatin- but not vincristine-induced mechanical sensitivity.

CONCLUSIONS AND IMPLICATIONS:

CBD may be potent and effective at preventing the development of CIPN, and its clinical utility may be enhanced by co-administration of low doses of THC. These treatment strategies would increase the therapeutic window of Cannabis-based pharmacotherapies.”

https://www.ncbi.nlm.nih.gov/pubmed/28548225

http://onlinelibrary.wiley.com/doi/10.1111/bph.13887/abstract

Selective Cannabinoids for Chronic Neuropathic Pain: A Systematic Review and Meta-analysis.

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“There is a lack of consensus on the role of selective cannabinoids for the treatment of neuropathic pain (NP). Guidelines from national and international pain societies have provided contradictory recommendations. The primary objective of this systematic review and meta-analysis (SR-MA) was to determine the analgesic efficacy and safety of selective cannabinoids compared to conventional management or placebo for chronic NP.

METHODS:

We reviewed randomized controlled trials that compared selective cannabinoids (dronabinol, nabilone, nabiximols) with conventional treatments (eg, pharmacotherapy, physical therapy, or a combination of these) or placebo in patients with chronic NP because patients with NP may be on any of these therapies or none if all standard treatments have failed to provide analgesia and or if these treatments have been associated with adverse effects. MEDLINE, EMBASE, and other major databases up to March 11, 2016, were searched. Data on scores of numerical rating scale for NP and its subtypes, central and peripheral, were meta-analyzed. The certainty of evidence was classified using the Grade of Recommendations Assessment, Development, and Evaluation approach.

RESULTS:

Eleven randomized controlled trials including 1219 patients (614 in selective cannabinoid and 605 in comparator groups) were included in this SR-MA. There was variability in the studies in quality of reporting, etiology of NP, type and dose of selective cannabinoids. Patients who received selective cannabinoids reported a significant, but clinically small, reduction in mean numerical rating scale pain scores (0-10 scale) compared with comparator groups (-0.65 points; 95% confidence interval, -1.06 to -0.23 points; P = .002, I = 60%; Grade of Recommendations Assessment, Development, and Evaluation: weak recommendation and moderate-quality evidence). Use of selective cannabinoids was also associated with improvements in quality of life and sleep with no major adverse effects.

CONCLUSIONS:

Selective cannabinoids provide a small analgesic benefit in patients with chronic NP. There was a high degree of heterogeneity among publications included in this SR-MA. Well-designed, large, randomized studies are required to better evaluate specific dosage, duration of intervention, and the effect of this intervention on physical and psychologic function.”

 https://www.ncbi.nlm.nih.gov/pubmed/28537982
http://insights.ovid.com/crossref?an=00000539-900000000-97514

Modulation of CB1 cannabinoid receptor by allosteric ligands: Pharmacology and therapeutic opportunities.

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“Cannabinoid pharmacology has been intensely studied because of cannabis’ pervasive medicinal and non-medicinal uses as well as for the therapeutic potential of cannabinoid-based drugs for the treatment of pain, anxiety, substance abuse, obesity, cancer and neurodegenerative disorders. The identification of allosteric modulators of the cannabinoid receptor 1 (CB1) has given a new direction to the development of cannabinoid-based therapeutics due to the many advantages offered by targeting allosteric site(s). Allosteric receptor modulators hold potential to develop subtype-specific and pathway-specific therapeutics. Here we briefly discuss the first-generation of allosteric modulators of CB1 receptor, their structure-activity relationships, signaling pathways and the allosteric binding site(s) on the CB1 receptor.”

https://www.ncbi.nlm.nih.gov/pubmed/28527758

http://www.sciencedirect.com/science/article/pii/S0028390817302307

Continuous Intrathecal Infusion of Cannabinoid Receptor Agonists Attenuates Nerve Ligation-Induced Pain in Rats.

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“Cannabinoid receptors (CB1R/CB2R) are known to play important roles in pain transmission.

In this study, we investigated the effects of continuous intrathecal infusion of CB1/2R agonists in the L5/6 spinal nerve ligation pain model.

Continuous intrathecal infusion of CB1/2R agonists elicits antinociception in the pain model.

The mechanisms might involve their actions on neurons and glial cells. CB2R, but not CB1R, seems to play an important role in the regulation of nerve injury-induced neuroinflammation.”

https://www.ncbi.nlm.nih.gov/pubmed/28492437

Cannabis as a substitute for prescription drugs – a cross-sectional study

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“The use of medical cannabis is increasing, most commonly for pain, anxiety and depression. Emerging data suggest that use and abuse of prescription drugs may be decreasing in states where medical cannabis is legal. The aim of this study was to survey cannabis users to determine whether they had intentionally substituted cannabis for prescription drugs.

A total of 1,248 (46%) respondents reported using cannabis as a substitute for prescription drugs. The most common classes of drugs substituted were narcotics/opioids (35.8%), anxiolytics/benzodiazepines (13.6%) and antidepressants (12.7%). A total of 2,473 substitutions were reported or approximately two drug substitutions per affirmative respondent.

These patient-reported outcomes support prior research that individuals are using cannabis as a substitute for prescription drugs, particularly, narcotics/opioids, and independent of whether they identify themselves as medical or non-medical users. This is especially true if they suffer from pain, anxiety and depression. Additionally, this study suggests that state laws allowing access to, and use of, medical cannabis may not be influencing individual decision-making in this area.”

https://www.dovepress.com/cannabis-as-a-substitute-for-prescription-drugs-ndash-a-cross-sectiona-peer-reviewed-article-JPR

Combined cannabinoid therapy via an oromucosal spray.

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“Extensive basic science research has identified the potential therapeutic benefits of active compounds extracted from the Cannabis sativa L. plant (the cannabinoids). It is recognized that a significant proportion of patients suffering with the debilitating symptoms of pain and spasticity in multiple sclerosis or other conditions smoke cannabis despite the legal implications and stigma associated with this controlled substance. GW Pharmaceuticals have developed Sativex (GW- 1000-02), a combined cannabinoid medicine that delivers and maintains therapeutic levels of two principal cannabinoids, delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD), via an oromucosal pump spray, that aims to minimize psychotropic side effects.”  https://www.ncbi.nlm.nih.gov/pubmed/16969427

“Sativex has proved to be well tolerated and successfully self-administered and self-titrated in both healthy volunteers and patient cohorts. Clinical assessment of this combined cannabinoid medicine has demonstrated efficacy in patients with intractable pain (chronic neuropathic pain, pain due to brachial plexus nerve injury, allodynic peripheral neuropathic pain and advanced cancer pain), rheumatoid arthritis and multiple sclerosis (bladder problems, spasticity and central pain), with no significant intoxication-like symptoms, tolerance or withdrawal syndrome.”  https://journals.prous.com/journals/servlet/xmlxsl/pk_journals.xml_summaryn_pr?p_JournalId=4&p_RefId=1021517

“Sativex(®) (nabiximols, USAN name) oromucosal spray contains the two main active constituents of Cannabis sativa, tetrahydrocannabinol and cannabidiol in a 1:1 molecular ratio, and acts as an endocannabinoid system modulator.”  https://www.ncbi.nlm.nih.gov/pubmed/21449855

“Abuse potential and psychoactive effects of δ-9-tetrahydrocannabinol and cannabidiol oromucosal spray (Sativex), a new cannabinoid medicine. Evidence to date suggests that abuse or dependence on Sativex is likely to occur in only a very small proportion of recipients.” https://www.ncbi.nlm.nih.gov/pubmed/21542664

Cannabinoid CB2 receptor ligand profiling reveals biased signalling and off-target activity

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“The cannabinoid CB2 receptor (CB2R) represents a promising therapeutic target for various forms of tissue injury and inflammatory diseases. There is a great interest in the development of selective type-2 cannabinoid receptor (CB2R) agonists as potential drug candidates for various pathophysiological conditions, which include chronic and inflammatory pain, pruritus, diabetic neuropathy and nephropathy, liver cirrhosis, and protective effects after ischaemic-reperfusion injury.” https://www.nature.com/articles/ncomms13958

“Pain relief without the high. Researchers at Leiden University led by Mario van der Stelt (Leiden Institute for Chemistry) have set ‘gold standards’ for developing new painkillers based on the medicinal effects of cannabis.”  https://www.sciencedaily.com/releases/2017/01/170104103916.htm

ScienceDaily

Anti-inflammatory effects of the cannabidiol derivative dimethylheptyl-cannabidiol – studies in BV-2 microglia and encephalitogenic T cells

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“Preparations derived from Cannabis sativa (marijuana and hashish) have become widespread since ancient times, both as therapeutic agents and in recreational smoking.

Among the more than 60 phytocannabinoids identified in Cannabis extracts, the two most abundant are Δ9-tetrahydrocannabinol (THC), the major psychotropic constituent, and cannabidiol (CBD), the major non-psychoactive component.

Cannabinoids were shown to exert a wide range of therapeutic effects, and many of the cannabinoids, especially CBD, were shown to possess potent anti-inflammatory and immunomodulatory activities. In addition, it was shown that several cannabinoids have pro-apoptotic, neuroprotective, and antitumor properties

Dimethylheptyl-cannabidiol (DMH-CBD), a non-psychoactive, synthetic derivative of the phytocannabinoid cannabidiol (CBD), has been reported to be anti-inflammatory in RAW macrophages. Here, we evaluated the effects of DMH-CBD at the transcriptional level in BV-2 microglial cells as well as on the proliferation of encephalitogenic T cells.

The results show that DMH-CBD has similar anti-inflammatory properties to those of CBD. DMH-CBD downregulates the expression of inflammatory cytokines and protects the microglial cells by inducing an adaptive cellular response against inflammatory stimuli and oxidative injury. In addition, DMH-CBD decreases the proliferation of pathogenic activated TMOG cells.

Several CBD derivatives were also shown to have anti-inflammatory and anti-proliferative properties.

The results show that DMH-CBD induces similar anti-inflammatory, anti-proliferative, and stress response effects to those previously observed for CBD.”

https://www.degruyter.com/view/j/jbcpp.2016.27.issue-3/jbcpp-2015-0071/jbcpp-2015-0071.xml

Substitution of medical cannabis for pharmaceutical agents for pain, anxiety, and sleep.

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“A prior epidemiological study identified a reduction in opioid overdose deaths in US states that legalized medical cannabis (MC). One theory to explain this phenomenon is a potential substitution effect of MC for opioids. This study evaluated whether this substitution effect of MC for opioids also applies to other psychoactive medications.

New England dispensary members ( n = 1,513) completed an online survey about their medical history and MC experiences. Among respondents that regularly used opioids, over three-quarters (76.7%) indicated that they reduced their use since they started MC. This was significantly ( p < 0.0001) greater than the patients that reduced their use of antidepressants (37.6%) or alcohol (42.0%). Approximately two-thirds of patients decreased their use of anti-anxiety (71.8%), migraine (66.7%), and sleep (65.2%) medications following MC which significantly ( p < 0.0001) exceeded the reduction in antidepressants or alcohol use. The patient’s spouse, family, and other friends were more likely to know about their MC use than was their primary care provider.

In conclusion, a majority of patients reported using less opioids as well as fewer medications to treat anxiety, migraines, and sleep after initiating MC. A smaller portion used less antidepressants or alcohol. Additional research is needed to corroborate these self-reported, retrospective, cross-sectional findings using other data sources.”

https://www.ncbi.nlm.nih.gov/pubmed/28372506

Antihyperalgesic Activities of Endocannabinoids in a Mouse Model of Antiretroviral-Induced Neuropathic Pain.

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“Nucleoside reverse transcriptase inhibitors (NRTIs) are the cornerstone of the antiretroviral therapy for human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS). However, their use is sometimes limited by the development of a painful sensory neuropathy, which does not respond well to drugs.

Smoked cannabis has been reported in clinical trials to have efficacy in relieving painful HIV-associated sensory neuropathy.

The aim of this study was to evaluate whether the expression of endocannabinoid system molecules is altered during NRTI-induced painful neuropathy, and also whether endocannabinoids can attenuate NRTI-induced painful neuropathy.

Conclusion: These data show that ddC induces thermal hyperalgesia, which is associated with dysregulation of the mRNA expression of some endocannabinoid system molecules. The endocannabinoids AEA and 2-AG have antihyperalgesic activity, which is dependent on cannabinoid receptor and GPR55 activation. Thus, agonists of cannabinoid receptors and GPR55 could be useful therapeutic agents for the management of NRTI-induced painful sensory neuropathy.”

https://www.ncbi.nlm.nih.gov/pubmed/28373843