“In animal studies, four times less morphine and ten times less codeine was needed when cannabinoids were given at the same time.
Category Archives: Chronic Inflammatory and Neuropathic Pain
The cannabinoid system and pain.
“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.”
https://www.ncbi.nlm.nih.gov/pubmed/28625720
http://www.sciencedirect.com/science/article/pii/S002839081730285X
Medicinal Uses of Marijuana and Cannabinoids
“In the past two decades, there has been increasing interest in the therapeutic potential of cannabis and single cannabinoids, mainly cannabidiol (CBD) and delta-9-tetrahydrocannabinol (THC). THC and cannabis products rich in THC exert their effects mainly through the activation of cannabinoid receptors (CB1 and CB2). Since 1975, 140 controlled clinical trials using different cannabinoids or whole-plant preparations for the treatment of a large number of disorders and symptoms have been conducted. Results have led to the approval of cannabis-based medicines [dronabinol, nabilone, and the cannabis extract nabiximols (Sativex®, THC:CBD = 1:1)] as well as cannabis flowers in several countries. Controlled clinical studies provide substantial evidence for the use of cannabinoid receptor agonists in cancer chemotherapy induced nausea and vomiting, appetite loss and cachexia in cancer and HIV patients, neuropathic and chronic pain, and in spasticity in multiple sclerosis. In addition, there is also some evidence suggesting a therapeutic potential of cannabis-based medicines in other indications including Tourette syndrome, spinal cord injury, Crohn’s disease, irritable bowel syndrome, and glaucoma. In several other indications, small uncontrolled and single-case studies reporting beneficial effects are available, for example in posttraumatic stress disorder, attention deficit hyperactivity disorder, and migraine. The most common side effects of THC and cannabis-based medicines rich in THC are sedation and dizziness (in more than 10% of patients), psychological effects, and dry mouth. Tolerance to these side effects nearly always develops within a short time. Withdrawal symptoms are hardly ever a problem in the therapeutic setting. In recent years there is an increasing interest in the medical use of CBD, which exerts no intoxicating side effects and is usually well-tolerated. Preliminary data suggest promising effects in the treatment of anxiety disorders, schizophrenia, dystonia, and some forms of epilepsy. This review gives an overview on clinical studies which have been published over the past 40 years.”
http://www.tandfonline.com/doi/abs/10.1080/07352689.2016.1265360?needAccess=true&journalCode=bpts20
“Review Identifies 140 Controlled Clinical Trials Related to Cannabis” http://blog.norml.org/2017/06/04/review-identifies-140-controlled-clinical-trials-related-to-cannabis/
Problematic Use of Prescription Opioids and Medicinal Cannabis Among Patients Suffering from Chronic Pain
“To assess prevalence rates and correlates of problematic use of prescription opioids and medicinal cannabis (MC) among patients receiving treatment for chronic pain.
Problematic use of opioids is common among chronic pain patients treated with prescription opioids and is more prevalent than problematic use of cannabis among those receiving MC.”
Cannabis and intractable chronic pain: an explorative retrospective analysis of Italian cohort of 614 patients.
“Despite growing interest in the therapeutic use of cannabis to manage chronic pain, only limited data that address these issues are available. In recent years, a number of nations have introduced specific laws to allow patients to use cannabis preparations to treat a variety of medical conditions. In 2015, the Italian government authorized the use of cannabis to treat several diseases, including chronic pain generally, spasticity in multiple sclerosis, cachexia and anorexia among AIDS and cancer patients, glaucoma, Tourette syndrome, and certain types of epilepsy. We present the first snapshot of the Italian experience with cannabis use for chronic pain over the initial year of its use.
METHODS:
This is a retrospective case series analysis of all chronic pain patients treated with oral or vaporized cannabis in six hubs during the initial year following the approval of the new Italian law (December 2015 to November 2016). We evaluated routes of administration, types of cannabis products utilized, dosing, and effectiveness and safety of the treatment.
RESULTS:
As only one of the six centers has extensively used cannabinoids for intractable chronic pain (614 patients of 659), only the population from Azienda Ospedaliero Universitaria Pisana (Pisa) was considered. Cannabis tea was the primary mode of delivery, and in almost all cases, it was used in association with all the other pain treatments. Initial and follow-up cannabinoid concentrations were found to vary considerably. At initial follow-up, 76.2% of patients continued the treatment, and <15% stopped the treatment due to side effects (none of which were severe).
CONCLUSION:
We present the first analysis of Italian clinical practice of the use of cannabinoids for a large variety of chronic pain syndromes. From this initial snapshot, we determined that the treatment seems to be effective and safe, although more data and subsequent trials are needed to better investigate its ideal clinical indication.”
The Analgesic Potential of Cannabinoids
“Cannabinoids are derivatives of Cannabis sativa, the hemp plant, which evolved in the temperate regions of Central Asia. Cannabis was used as a medicine in ancient China (2700 BC) and India (1000 BC). Historically and anecdotally cannabinoids have been used as analgesic agents.
In recent years, there has been an escalating interest in developing cannabis-derived medications to treat severe pain. This review provides an overview of the history of cannabis use in medicine, cannabinoid signaling pathways, and current data from preclinical as well as clinical studies on using cannabinoids as potential analgesic agents. Clinical and experimental studies show that cannabis-derived compounds act as anti-emetic, appetite modulating and analgesic agents.
Since opioids are the only therapy for severe pain, analgesic ability of cannabinoids may provide a much-needed alternative to opioids. Moreover, cannabinoids act synergistically with opioids and act as opioid sparing agents, allowing lower doses and fewer side effects from chronic opioid therapy. Thus, rational use of cannabis based medications deserves serious consideration to alleviate the suffering of patients due to severe pain.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3728280/
[Therapeutic potential of Cannabis sativa].
“Cannabis sativa (marihuana) is considered an illicit drug due to its psychoactive properties. Recently, the Chilean government opened to the use cannabis in the symptomatic treatment of some patients. The biological effects of cannabis render it useful for the complementary treatment of specific clinical situations such as chronic pain. We retrieved scientific information about the analgesic properties of cannabis, using it as a safe drug. The drug may block or inhibit the transmission of nervous impulses at different levels, an effect associated with pain control. Within this context and using adequate doses, forms and administration pathways, it can be used for chronic pain management, considering its effectiveness and low cost. It could also be considered as an alternative in patients receiving prolonged analgesic therapies with multiple adverse effects.”
Single and combined effects of delta9 -tetrahydrocannabinol and cannabidiol in a mouse model of chemotherapy-induced neuropathic pain.
“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.
“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.”
Continuous Intrathecal Infusion of Cannabinoid Receptor Agonists Attenuates Nerve Ligation-Induced Pain in Rats.
“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.