Category Archives: Neuropathic Pain

Antinociceptive Synergy between 9 -Tetrahydrocannabinol and Opioids after Oral Administration

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“Cannabinoids and opioids have been shown to possess several similar pharmacological effects, including analgesia

The analgesic effects of opioids, such as morphine and codeine, in mice are enhanced by oral administration of the cannabinoid 9 -tetrahydrocannabinol (9 -THC).

These findings suggest that the use of a low-dose combination of analgesics is a valid and effective approach for the treatment of pain and necessitates further study.

In summary, we have observed that 9 -THC enhances the antinociceptive effects of morphine and codeine in a synergistic fashion. This is the first report of a true synergistic interaction between oral 9 -THC and morphine or codeine, since previous studies have only examined one-dose combinations.

Much more work needs to be done to elucidate the mechanisms by which cannabinoids and opioids interact to produce analgesia. However, the implication that a combination of drugs may be more effective than either drug alone, and at the same time possibly reduce the occurrence of side effects, should provoke further study on analgesic drug interactions.”

http://jpet.aspetjournals.org/content/jpet/304/3/1010.full.pdf

http://healthdocbox.com/Substance_Abuse/71109245-Antinociceptive-synergy-between-9-tetrahydrocannabinol-and-opioids-after-oral-administration.html

Molecular and cellular basis of cannabinoid and opioid interactions.

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 Pharmacology Biochemistry and Behavior

“Cannabinoids and opioids have been shown to possess several similar pharmacological effects, including analgesia and stimulation of brain circuitry that are believed to underlie drug addiction and reward. In recent years, these phenomena have supported the possible existence of functional links in the mechanisms of action of both types of drugs.

The present review addresses the recent advances in the study of biochemical and molecular mechanisms underlying opioid and cannabinoid interaction. Several hypothesis have been formulated to explain this cross-modulation including the release of opioid peptides by cannabinoids or endocannabinoids by opioids and interaction at the level of receptor and/or their signal transduction mechanisms.

Moreover it is important to consider that the nature of cannabinoid and opioid interaction might differ in the brain circuits mediating reward and in those mediating other pharmacological properties, such as antinociception.

Further studies are needed since a better knowledge of the opioid-cannabinoid interaction may lead to exciting therapeutic possibilities.”

https://www.ncbi.nlm.nih.gov/pubmed/15927245

https://www.sciencedirect.com/science/article/pii/S0091305705001450?via%3Dihub

Opioids and cannabinoids interactions: involvement in pain management.

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“Among several pharmacological properties, analgesia is the most common feature shared by either opioid or cannabinoid systems.

Cannabinoids and opioids are distinct drug classes that have been historically used separately or in combination to treat different pain states.

Indeed, it is widely known that activation of either opioid or cannabinoid systems produce antinociceptive properties in different pain models.

Moreover, several biochemical, molecular and pharmacological studies support the existence of reciprocal interactions between both systems, suggesting a common underlying mechanism.

Further studies have demonstrated that the endogenous opioid system could be involved in cannabinoid antinociception and recent data have also provided evidence for a role of the endogenous cannabinoid system in opioid antinociception.

These interactions may lead to additive or even synergistic antinociceptive effects, emphasizing their clinical relevance in humans in order to enhance analgesic effects with lower doses and consequently fewer undesirable side effects.

Thus, the present review is focused on bidirectional interactions between opioids and cannabinoids and their potent repercussions on pain modulation.”

https://www.ncbi.nlm.nih.gov/pubmed/20017728

http://www.eurekaselect.com/71318/article

Synergistic interactions of endogenous opioids and cannabinoid systems.

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 Brain Research

“Cannabinoids and opioids are distinct drug classes historically used in combination to treat pain. Delta(9)-THC, an active constituent in marijuana, releases endogenous dynorphin A and leucine enkephalin in the production of analgesia.

The endocannabinoid, anandamide (AEA), fails to release dynorphin A. The synthetic cannabinoid, CP55,940, releases dynorphin B. Neither AEA nor CP55,940 enhances morphine analgesia. The CB1 antagonist, SR141716A, differentially blocks Delta(9)-THC versus AEA. Tolerance to Delta(9)-THC, but not AEA, involves a decrease in the release of dynorphin A.

Our preclinical studies indicate that Delta(9)-THC and morphine can be useful in low dose combination as an analgesic. Such is not observed with AEA or CP55,940.

We hypothesize the existence of a new CB receptor differentially linked to endogenous opioid systems based upon data showing the stereoselectivity of endogenous opioid release. Such a receptor, due to the release of endogenous opioids, may have significant impact upon the clinical development of cannabinoid/opioid combinations for the treatment of a variety of types of pain in humans.”

https://www.ncbi.nlm.nih.gov/pubmed/10612710

https://www.sciencedirect.com/science/article/pii/S0006899399019083?via%3Dihub

Synergistic interactions between cannabinoid and opioid analgesics.

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Life Sciences

“Cannabinoids and opioids both produce analgesia through a G-protein-coupled mechanism that blocks the release of pain-propagating neurotransmitters in the brain and spinal cord. However, high doses of these drugs, which may be required to treat chronic, severe pain, are accompanied by undesirable side effects.

Thus, a search for a better analgesic strategy led to the discovery that delta 9-tetrahydrocannabinol (THC), the major psychoactive constituent of marijuana, enhances the potency of opioids such as morphine in animal models.

In addition, studies have determined that the analgesic effect of THC is, at least in part, mediated through delta and kappa opioid receptors, indicating an intimate connection between cannabinoid and opioid signaling pathways in the modulation of pain perception.

A host of behavioral and molecular experiments have been performed to elucidate the role of opioid receptors in cannabinoid-induced analgesia. The aim of such studies is to develop a novel analgesic regimen using low dose combinations of cannabinoids and opioids to effectively treat acute and chronic pain, especially pain that may be resistant to opioids alone.”

 https://www.ncbi.nlm.nih.gov/pubmed/14706563
https://www.sciencedirect.com/science/article/pii/S0024320503010129?via%3Dihub

Interaction of the cannabinoid and opioid systems in the modulation of nociception

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Publication Cover

“Cannabinoids and opioids produce antinociceptive synergy.

Cannabinoids such as Δ-9-tetrahydrocannabinol (THC) release endogenous opioids and endocannabinoids such as anandamide (AEA) also alter endogenous opioid tone.

Opioids and cannabinoids bind distinct receptors that co-localize in areas of the brain involved with the processing of pain signals. Therefore, it is logical to look at interactions of these two systems in the modulation of both acute and chronic pain.

This review summarizes the data indicating that with cannabinoid/opioid therapy one may be able to produce long-term antinociceptive effects at doses devoid of substantial side effects, while preventing the neuronal biochemical changes that accompany tolerance.

The clinical utility of modulators of the endocannabinoid system as a potential mimic for THC-like drugs in analgesia and tolerance-sparing effects of opioids is a critical future direction also addressed in the review.”

https://www.tandfonline.com/doi/abs/10.1080/09540260902782794

Pharmacotherapeutic considerations for use of cannabinoids to relieve pain in patients with malignant diseases.

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“The aim of this review was to assess the efficacy of cannabis preparations for relieving pain in patients with malignant diseases, through a systematic review of randomized controlled trials (RCTs), which were predominantly double-blind trials that compared cannabis preparation to a placebo.

RESULTS:

Fifteen of the 18 trials demonstrated a significant analgesic effect of cannabinoids as compared to placebo. The most commonly reported adverse effects were generally well tolerated, mild to moderate. The main side effects were drowsiness, nausea, vomiting and dry mouth. There is evidence that cannabinoids are safe and modestly effective in neuropathic pain and also for relieving pain in patients with malignant diseases. The proportion of “responders” (patients who at the end of 2 weeks of treatment reported ≥30% reduction in pain intensity on a scale of 0-10, which is considered to be clinically important) was 43% in comparison with placebo (21%).

CONCLUSION:

The target dose for relieving pain in patients with malignant diseases is most likely about 10 actuations per day, which is about 27 mg tetrahydrocannabinol (THC) and 25 mg cannabidiol (CBD), and the highest approved recommended dose is 12 actuations per day (32 mg THC/30 mg CBD). Further large studies of cannabinoids in homogeneous populations are required.”

https://www.ncbi.nlm.nih.gov/pubmed/29719417

https://www.dovepress.com/pharmacotherapeutic-considerations-for-use-of-cannabinoids-to-relieve–peer-reviewed-article-JPR

Systematic review of systematic reviews for medical cannabinoids: Pain, nausea and vomiting, spasticity, and harms.

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“To determine the effects of medical cannabinoids on pain, spasticity, and nausea and vomiting, and to identify adverse events.

Systematic reviews with 2 or more randomized controlled trials (RCTs) that focused on medical cannabinoids for pain, spasticity, or nausea and vomiting were included.

 

There is reasonable evidence that cannabinoids improve nausea and vomiting after chemotherapy.

They might improve spasticity (primarily in multiple sclerosis).

There is some uncertainty about whether cannabinoids improve pain, but if they do, it is neuropathic pain”

https://www.ncbi.nlm.nih.gov/pubmed/29449262

Medical Cannabis for Neuropathic Pain.

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Current Pain and Headache Reports

“Many cultures throughout history have used cannabis to treat a variety of painful ailments. Neuropathic pain is a complicated condition that is challenging to treat with our current medications.

Recent scientific discovery has elucidated the intricate role of the endocannabinoid system in the pathophysiology of neuropathic pain. As societal perceptions change, and legislation on medical cannabis relaxes, there is growing interest in the use of medical cannabis for neuropathic pain.

We examined current basic scientific research and data from recent randomized controlled trials (RCTs) evaluating medical cannabis for the treatment of neuropathic pain.

These studies involved patients with diverse etiologies of neuropathic pain and included medical cannabis with different THC concentrations and routes of administration. Multiple RCTs demonstrated efficacy of medical cannabis for treating neuropathic pain, with number needed to treat (NNT) values similar to current pharmacotherapies.

Although limited by small sample sizes and short duration of study, the evidence appears to support the safety and efficacy of short-term, low-dose cannabis vaporization and oral mucosal delivery for the treatment of neuropathic pain.

The results suggest medical cannabis may be as tolerable and effective as current neuropathic agents; however, more studies are needed to determine the long-term effects of medical cannabis use. Furthermore, continued research to optimize dosing, cannabinoidratios, and alternate routes of administration may help to refine the therapeutic role of medical cannabis for neuropathic pain.”

https://www.ncbi.nlm.nih.gov/pubmed/29388063

https://link.springer.com/article/10.1007%2Fs11916-018-0658-8

WWL70 protects against chronic constriction injury-induced neuropathic pain in mice by cannabinoid receptor-independent mechanisms.

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“Targeting the endocannabinoid system has emerged as an effective strategy for the treatment of inflammatory and neurological diseases.

Unlike the inhibition of the principal 2-arachidonyl glycerol (2-AG) hydrolytic enzyme monoacylglycerol lipase (MAGL), which leads to 2-AG overload and cannabinoid receptor desensitization, selective inhibition of the minor 2-AG hydrolytic enzyme alpha, beta-hydrolase domain 6 (ABHD6) can provide therapeutic benefits without producing cannabimimetic side effects. We have shown that inhibition of ABHD6 significantly reduces neuroinflammation and exerts neuroprotection in animal models of traumatic brain injury and multiple sclerosis. However, the role of ABHD6 inhibition on neuropathic pain has not been explored.

CONCLUSIONS:

This study reveals a novel mechanism for the antinociceptive effect of the 2-AG catabolic enzyme ABHD6 inhibitor WWL70. Understanding the interaction between endocannabinoid and eicosanoid pathways might provide a new avenue for the treatment of inflammatory and neuropathic pain.”

 https://www.ncbi.nlm.nih.gov/pubmed/29310667
https://jneuroinflammation.biomedcentral.com/articles/10.1186/s12974-017-1045-9