Cannabis Reduces Opioid Dose in the Treatment of Chronic Non-Cancer Pain

Image result for journal of pain and symptom management

“Cannabinoids block pain responses in virtually every laboratory pain model tested.

In models of acute or physiological pain, cannabinoids are highly effective against thermal, mechanical, and chemical pain, and are comparable to opioids in potency and efficacy.1 In models of chronic pain, cannabinoids exhibit efficacy in the modulation of both inflammatory2 and neuropathic pain.3

Recent reviews describe an endogenous cannabinoid system involved in pain modulation that produces analgesia through the same brainstem circuitry involved in opioid analgesia.1., 4., 5., 6. Although co-administration of Δ-9-tetrahydrocannabinol (THC) with μ opioid agonists can potentiate the antinociceptive effects of each agent, an opioid is not required for cannabinoid analgesia.5., 6. Co-administration of a cannabinoid may lead to a lower opioid requirement. In an N-of-1 trial, oral THC reduced the pain of familial Mediterranean fever such that the use of breakthrough opioid for pain relief decreased significantly.7

Recently, in Canada, the Medical Marijuana Access Program allows patients to apply to Health Canada for access to dried cannabis for medicinal purposes. Although smoked cannabis is not an ideal delivery system, it is efficient and results in plasma concentration curves parallel to those seen after intravenous administration.8 We present three patients who used small doses of smoked marijuana in combination with an opioid.

These cases are consistent with preclinical work demonstrating that cannabinoids exhibit analgesic effects and may potentiate the antinociceptive effects of opioids. These patients were able to decrease the dose of opioid by 60–100% as compared to before the regular use of smoked marijuana. With the introduction of smoked marijuana, each patient reported better pain control.

Unfortunately, the source of smoked marijuana used by patients, and the percentage of THC in it, is unknown. All patients reported previous exposure to cannabis at some time in their lives before the onset of their pain, and the relevance of this experience also is unknown. Standardized measures of pain were not used, and the information presented was based on the patients’ verbal report when they presented for follow-up appointments at the Pain Management Unit. Nonetheless, these cases suggest that further research regarding the role of cannabinoids as analgesics and the combination of cannabinoids with opioids in the control of pain is needed.”

http://www.jpsmjournal.com/article/S0885-3924(03)00142-8/fulltext

Cannabis in Chinese Medicine: Are Some Traditional Indications Referenced in Ancient Literature Related to Cannabinoids?

Image result for frontiers pharmacology

“Cannabis sativa L. has been cultivated in China for millennia for use as a fiber, food, and medicine. Cannabis sativa L. (Cannabaceae) has a long history of utilization as a fiber and seed crop in China, and its achenes (“seeds”) as well as other plant parts have been recorded in Chinese medical texts for nearly 2000 years.

While the primary applications of cannabis in Chinese medicine center around the use of the achenes, ancient indications for the female inflorescence, and other plant parts include conditions such as pain and mental illness that are the subject of current research into cannabinoids such as cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC).

In this article, prominent historical applications of cannabis in Chinese medicine are chronologically reviewed, and indications found in ancient Chinese literature that may relate to cannabinoids such as CBD and Δ9-THC are investigated.

In recent years, cannabinoids such as CBD and Δ9-THC have attracted increased attention in the context of modern pharmacology and popular Western culture, yet little research has been done to explore the historical applications of cannabis in Chinese medicine. Given China’s long history of hemp cultivation and its rich body of un-translated medical literature, it is surprising that little academic attention has focused on exploring the ways in which cannabis was used in Chinese medicine. The importance of cannabis as a fiber and food crop in ancient China, combined with the extensive use of the achenes in medicine, makes the Chinese historical record particularly valuable.

Bencao literature opens a window into the history and culture of ancient Chinese medicine. As all parts of the cannabis plant were recorded in bencao texts, the Chinese medical literature can help to clarify many details about the historical applications of cannabis in Chinese medicine, as well as providing clues into the historical prevalence of different biotypes as ancient Chinese farmers gradually selected superior varieties for fiber and seed crops.

The significant differences in how cannabis has been employed in Chinese vs. Western medicine likely relate to differences between drug and fiber biotypes as well as cultural factors, but thus far minimal research has focused on exploring this issue. Similarly, minimal attention has been given to the topic of CBD in Chinese medical history, as even fiber-rich biotypes of cannabis that were not associated with drug use may have had potential therapeutic applications related to CBD. While this modest review can only scratch the surface of the Chinese medical literature of cannabis and the questions it raises, it is hoped that further research will help to further elucidate these questions using a multidisciplinary approach.”

http://journal.frontiersin.org/article/10.3389/fphar.2017.00108/full

Cannabinoids therapeutic use: what is our current understanding following the introduction of THC, THC:CBD oromucosal spray and others?

 

Image result for Expert Rev Clin Pharmacol

“The complexity of the endocannabinoid (eCB) system is becoming better understood and new drivers of eCB signaling are emerging. Modulation of the activities of the eCB system can be therapeutic in a number of diseases.

Research into the eCB system has been paralleled by the development of agents that interact with cannabinoid receptors. In this regard it should be remembered that herbal cannabis contains a myriad of active ingredients, and the individual cannabinoids have quite distinct biological activities requiring independent studies.

This article reviews the most important current data involving the eCB system in relation to human diseases, to reflect the present (based mainly on the most used prescription cannabinoid medicine, THC/CBD oromucosal spray) and potential future uses of cannabinoid-based therapy.

Expert commentary: From the different therapeutic possibilities, THC/CBD oromucosal spray has been in clinical use for approximately five years in numerous countries world-wide for the management of multiple sclerosis (MS)-related moderate to severe resistant spasticity.

Clinical trials have confirmed its efficacy and tolerability.

Other diseases in which different cannabinoids are currently being investigated include various pain states, Alzheimer’s disease, Parkinson’s disease, Huntington’s disease and epilepsy. The continued characterization of individual cannabinoids in different diseases remains important.”

https://www.ncbi.nlm.nih.gov/pubmed/28276775

Cannabinoids for treating inflammatory bowel diseases: where are we and where do we go?

Image result for Expert Rev Gastroenterol Hepatol.

“Fifty years after the discovery of Δ9-tetrahydrocannabinol (THC) as the psychoactive component of Cannabis, we are assessing the possibility of translating this herb into clinical treatment of inflammatory bowel diseases (IBDs).

Here, a discussion on the problems associated with a potential treatment is given.

From first surveys and small clinical studies in patients with IBD we have learned that Cannabis is frequently used to alleviate diarrhea, abdominal pain, and loss of appetite.

Single ingredients from Cannabis, such as THC and cannabidiol, commonly described as cannabinoids, are responsible for these effects. Synthetic cannabinoid receptor agonists are also termed cannabinoids, some of which, like dronabinol and nabilone, are already available with a narcotic prescription.

Recent data on the effects of Cannabis/cannabinoids in experimental models of IBD and in clinical trials with IBD patients have been reviewed using a PubMed database search. A short background on the endocannabinoid system is also provided.

Expert commentary: Cannabinoids could be helpful for certain symptoms of IBD, but there is still a lack of clinical studies to prove efficacy, tolerability and safety of cannabinoid-based medication for IBD patients, leaving medical professionals without evidence and guidelines.”

Medical marijuana policies and hospitalizations related to marijuana and opioid pain reliever.

Image result for Drug Alcohol Depend

“Twenty-eight states in the U.S have legalized medical marijuana, yet its impacts on severe health consequences such as hospitalizations remain unknown. Meanwhile, the prevalence of opioid pain reliever (OPR) use and outcomes has increased dramatically. Recent studies suggested unintended impacts of legalizing medical marijuana on OPR, but the evidence is still limited. This study examined the associations between state medical marijuana policies and hospitalizations related to marijuana and OPR.

Hospitalizations related to marijuana and OPR increased sharply by 300% on average in all states. Medical marijuana legalization was associated with 23% (p=0.008) and 13% (p=0.025) reductions in hospitalizations related to opioid dependence or abuse and OPR overdose, respectively; lagged effects were observed after policy implementation. The operation of medical marijuana dispensaries had no independent impacts on OPR-related hospitalizations. Medical marijuana polices had no associations with marijuana-related hospitalizations.

Medical marijuana policies were significantly associated with reduced OPR-related hospitalizations but had no associations with marijuana-related hospitalizations. Given the epidemic of problematic use of OPR, future investigation is needed to explore the causal pathways of these findings.”

https://www.ncbi.nlm.nih.gov/pubmed/28259087

Does Cannabidiol Protect Against Adverse Psychological Effects of THC?

Image result for Front Psychiatry.

“Tetrahydrocannabinol (THC) is the main psychoactive substance in cannabis. Cannabidiol (CBD) is a cannabinoid that appears in cannabis resin but rarely in herbal cannabis. In recent years, many positive attributes have been ascribed to CBD. Is cannabis that contains CBD less harmful than cannabis without CBD? Are people who smoke cannabis resin, therefore, less susceptible to psychosis or less likely to become addicted than are people who smoke herbal marijuana?

Delta-9-tetrahydrocannabinol (THC) is the main psychoactive constituent of cannabis, and most, if not all, of the effects associated with the use of cannabis are caused by THC. Recent studies have suggested a possible protective effect of another cannabinoid, cannabidiol (CBD).

Most recreational users will never be faced with persistent mental illness, but in some individuals cannabis use leads to undesirable effects: cognitive impairment, anxiety, paranoia, and increased risks of developing chronic psychosis or drug addiction.

Studies examining the protective effects of CBD have shown that CBD can counteract the negative effects of THC.

Few or no adverse effects of CBD have been proffered, and where CBD has been found to have an effect, it is usually in a “positive” (i.e., salubrious) direction. The evidence favoring a beneficial effect of CBD therefore merits further investigation in studies in which the amounts and ratios of CBD and THC correspond to the daily practices of recreational cannabis use.” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3797438/

“Studies examining the protective effects of CBD have shown that CBD can counteract the negative effects of THC.” https://www.ncbi.nlm.nih.gov/pubmed/24137134

“CBD may also potentiate some of Δ9-THC’s beneficial effects as it reduces Δ9-THC’s psychoactivity to enhance its tolerability and widen its therapeutic window.”  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4707667/

Cannabinoid signaling in health and disease.

Image result for Canadian Journal of Physiology and Pharmacology

“Cannabis sativa has long been used for medicinal purposes.

To improve safety and efficacy, compounds from C. sativa were purified or synthesized and named under an umbrella group as cannabinoids.

Currently, several cannabinoids may be prescribed in Canada for a variety of indications such as nausea and pain.

More recently, an increasing number of reports suggest other salutary effects associated with endogenous cannabinoid signaling including cardioprotection.

The therapeutic potential of cannabinoids is therefore extended; however, evidence is limited and mechanisms remain unclear.

In addition, the use of cannabinoids clinically has been hindered due to pronounced psychoactive side effects.

This review provides an overview on the endocannabinoid system, including known physiological roles, and conditions in which cannabinoid receptor signaling has been implicated.”

Cell-Autonomous Excitation of Midbrain Dopamine Neurons by Endocannabinoid-Dependent Lipid Signaling.

Image result for neuron journal

“The major endocannabinoid in the mammalian brain is the bioactive lipid 2-arachidonoylglycerol (2-AG). The best-known effects of 2-AG are mediated by G-protein-coupled cannabinoid receptors. In principle, 2-AG could modify neuronal excitability by acting directly on ion channels, but such mechanisms are poorly understood.

Using a preparation of dissociated mouse midbrain dopamine neurons to isolate effects on intrinsic excitability, we found that 100 nM 2-AG accelerated pacemaking and steepened the frequency-current relationship for burst-like firing. In voltage-clamp experiments, 2-AG reduced A-type potassium current (IA) through a cannabinoid receptor-independent mechanism mimicked by arachidonic acid, which has no activity on cannabinoid receptors. Activation of orexin, neurotensin, and metabotropic glutamate Gq/11-linked receptors mimicked the effects of exogenous 2-AG and their actions were prevented by inhibiting the 2-AG-synthesizing enzyme diacylglycerol lipase α.

The results show that 2-AG and related lipid signaling molecules can directly tune neuronal excitability in a cell-autonomous manner by modulating IA.”

https://www.ncbi.nlm.nih.gov/pubmed/28262417

Inflammatory Regulation by Driving Microglial M2 Polarization: Neuroprotective Effects of Cannabinoid Receptor-2 Activation in Intracerebral Hemorrhage.

Image result for Front Immunol.

“The cannabinoid receptor-2 (CB2R) was initially thought to be the “peripheral cannabinoid receptor.” Recent studies, however, have documented CB2R expression in the brain in both glial and neuronal cells, and increasing evidence suggests an important role for CB2R in the central nervous system inflammatory response.

Intracerebral hemorrhage (ICH), which occurs when a diseased cerebral vessel ruptures, accounts for 10-15% of all strokes. Although surgical techniques have significantly advanced in the past two decades, ICH continues to have a high mortality rate.

The aim of this study was to investigate the therapeutic effects of CB2R stimulation in acute phase after experimental ICH in rats and its related mechanisms.

These findings demonstrated that CB2R stimulation significantly protected the brain damage and suppressed neuroinflammation by promoting the acquisition of microglial M2 phenotype in acute stage after ICH.

Taken together, this study provided mechanism insight into neuroprotective effects by CB2R stimulation after ICH.”

Endocannabinoids: A Promising Impact for Traumatic Brain Injury.

 

Image result for Front Pharmacol

“The endogenous cannabinoid (endocannabinoid) system regulates a diverse array of physiological processes and unsurprisingly possesses considerable potential targets for the potential treatment of numerous disease states, including two receptors (i.e., CB1 and CB2 receptors) and enzymes regulating their endogenous ligands N-arachidonoylethanolamine (anandamide) and 2-arachidonyl glycerol (2-AG).

Increases in brain levels of endocannabinoids to pathogenic events suggest this system plays a role in compensatory repair mechanisms.

Traumatic brain injury (TBI) pathology remains mostly refractory to currently available drugs, perhaps due to its heterogeneous nature in etiology, clinical presentation, and severity. Here, we review pre-clinical studies assessing the therapeutic potential of cannabinoids and manipulations of the endocannabinoid system to ameliorate TBI pathology.

Specifically, manipulations of endocannabinoid degradative enzymes (e.g., fatty acid amide hydrolase, monoacylglycerol lipase, and α/β-hydrolase domain-6), CB1and CB2 receptors, and their endogenous ligands have shown promise in modulating cellular and molecular hallmarks of TBI pathology such as; cell death, excitotoxicity, neuroinflammation, cerebrovascular breakdown, and cell structure and remodeling.

TBI-induced behavioral deficits, such as learning and memory, neurological motor impairments, post-traumatic convulsions or seizures, and anxiety also respond to manipulations of the endocannabinoid system.

As such, the endocannabinoid system possesses potential drugable receptor and enzyme targets for the treatment of diverse TBI pathology.

Yet, full characterization of TBI-induced changes in endocannabinoid ligands, enzymes, and receptor populations will be important to understand that role this system plays in TBI pathology.

Promising classes of compounds, such as the plant-derived phytocannabinoids, synthetic cannabinoids, and endocannabinoids, as well as their non-cannabinoid receptor targets, such as TRPV1 receptors, represent important areas of basic research and potential therapeutic interest to treat TBI.”