Recent data on cannabinoids and their pharmacological implications in neuropathic pain.

Abstract

“Natural cannabinoids have been used for centuries for their psychotropic properties, but their possible therapeutic implications in analgesia have been recently documented. The present review intended to make an analysis of the neuroanatomy and physiology of the cannabinoid system (receptors, functions, agents acting on these receptors) and of its implications in neuropathic pain. There were also described the complex phenomena implicated in the generation and maintenance of neuropathic pain, by high lightening the implications of endogenous cannabinoids in this complex of painful conditions. The pharmacological analgesia test proves of cannabinoid implication in neuropathic pain was sustained by many studies presented in this paper. Therapeutic approaches using natural and synthetic cannabinoid receptor agonists were reviewed. Therapeutic perspectives in neuropathic pain might involve the development of new agents that influence the cannabinoid system. Thus, peripheral acting cannabinoid 1 receptors agonists, selective cannabinoid 2 receptor agonists and also modulators of endocannabinoids metabolism might be a way to success in the treatment of this complex entity called neuropathic pain.”

http://www.ncbi.nlm.nih.gov/pubmed/20108515

Research: Marijuana can treat chronic pain – ABC

“SACRAMENTO, CA (KGO) — A program commissioned more than a decade ago by the state Legislature to look into the therapeutic value of medicinal marijuana is expected to release a report on its findings today, a spokeswoman for state Sen. Mark Leno said.

A UC medical marijuana research panel today released the results of a ten year clinical study and according to its report, pot can effectively treat chronic pain.

Volunteers with multiple sclerosis and spinal cord injuries were randomly treated with marijuana or a placebo. Patients given cannabis reported fewer multiple sclerosis muscle spasms, and less spinal injury pain.

In another study, the panel found that pot effectively also treats migraines.

But researchers used marijuana grown by the federal government, not the kinds available to California medical marijuana users.

Medical marijuana has been legal under California law since voters approved Proposition 215, also known as the Compassionate Use Act, in 1996.

The state Legislature clarified in 2004 that the Compassionate Use Act allows qualified patients and their primary caregivers to cultivate marijuana for medicinal use.

Medical marijuana remains illegal under federal law, though, leaving patients and providers open to prosecution in federal court.”

http://abclocal.go.com/kgo/story?section=news/state&id=7283032

Marijuana component could ease pain from chemotherapy drugs

“A chemical component of the marijuana plant could prevent the onset of pain associated with drugs used in chemo therapy, particularly in breast cancer patients, according to researchers at Temple University’s School of Pharmacy.

“We found that cannabidiol completely prevented the onset of the neuropathic, or caused by the chemo drug Paclitaxel, which is used to treat ,” said Ward, who is also a research associate professor in Temple’s Center for Substance Abuse Research.

Ward said that one of cannabidiol’s major benefits is that, unlike other chemicals found in marijuana such as THC, it does not produce psycho-active effects such as euphoria, increased appetite or cognitive deficits. “Cannabidiol has the therapeutic qualities of marijuana but not the side effects,” she said.”

Read more: http://medicalxpress.com/news/2011-10-marijuana-component-ease-pain-chemotherapy.html

Cannabis spray blunts pain

 Erica Klarreich

“Early trials suggest cannabis spritz may give relief to chronic pain sufferers.”

Cannabis: 5,000 years of medicinal use.Cannabis: 5,000 years of medicinal use.© Photodisc

“A spray that delivers the active ingredient of cannabis under the tongue may ease chronic pain, preliminary clinical trials suggest.

Of the 23 patients who participated in the controlled study, only a few failed to respond to the spray, William Nortcutt of James Paget Hospital in Gorleston, UK told the British Association for the Advancement of Science’s Annual Festival of Science on Monday. Seventeen have gone on to use the drug to treat their pain in the long term, he said.

“Some of the patients said it made a huge difference; others just said it lets them sleep,” Nortcutt said. “But when you’re in chronic pain, being able to sleep is one of the most important things.”

Earlier clinical trials have also shown the pain-relieving benefits of cannabis. But researchers have struggled to find a good way to deliver the drug, says Roger Pertwee, a neuropharmacologist and cannabis expert at the University of Aberdeen, UK.

“The study with a spray is very interesting,” he says. “The past clinical trials have been with pills, but absorption by swallowing is very unreliable.”

About half of the trial’s participants had multiple sclerosis; the rest suffered chronic pain from severe nerve damage and spinal-cord injuries. Although a few of the multiple sclerosis patients had been using cannabis to treat pain before the trials, most participants had seldom or never used it.

The most common side-effect appeared to be dry mouth, Nortcutt reports. Several patients experienced panic or a high during tests to find appropriate dosages. Most preferred a drug in which the active substance, tetrahydrocannabinol (THC), was mixed with another, less psychoactive ingredient of cannabis. Previous clinical studies have involved only pure THC, Pertwee says.

The research comes as many groups are pushing for cannabis to be legalized for therapeutic use in the United Kingdom. If cannabis were to be made legal, Nortcutt says, the path to approval might be much faster than for typical drugs, which take an average of six years.

“There is a huge amount of anecdotal evidence that would help scientists,” Nortcutt told the Glasgow meeting. “We have to recognize that cannabis has been used for 5,000 years.” But much more work is needed to understand how cannabis might be exploited as a pain treatment, Nortcutt warned. “I wouldn’t call for it to be prescribed now.””

http://www.nature.com/news/1998/010906/full/news010906-7.html

 

The Endocannabinoid System and Pain

Gallery

“Cannabis has been used for more than twelve thousand years and for many different purposes (i.e. fiber, medicinal, recreational). However, the endocannabinoid signaling system has only recently been the focus of medical research and considered a potential therapeutic target. Endocannabinoids … Continue reading Continue reading

The cannabinoid system and pain: towards new drugs?

Abstract

“The various components of the endocannabinoid system were discovered in the last twenty years. The cannabinoid system has attracted pharmacologists interest for its potential as therapeutic targets for several diseases ranging from obesity to Parkinson’s disease and from multiple sclerosis to pain. Research initially focused on cannabinoid receptor 1 (CB1), but, due to psychotropic side effects related to its activation, the attempts to develop an agonist drug for this receptor has been so far unsuccessful. Recently the possibility to target CB2 has emerged as an alternative for the treatment of pain. The main advantage of targeting CB2 resides in the possibility to elicit the analgesic effect without the psychotropic side effects. Evidence of the analgesic effect of CB2 selective agonists has been obtained in various models of both inflammatory and neuropathic chronic pain. To explain the mechanism at the basis of this analgesic effect different hypotheses have been proposed: effect on inflammatory cells, reduction of basal NGF tone, induction of beta-endorphin release from keratinocytes, direct action on nociceptors. Evidence in support of this last hypothesis comes from down regulation of capsaicin-induced CGRP release in spinal cord slices and Dorsal Root Ganglia (DRG) neurons in culture after treatment with CB2 selective agonists. CB2 agonists are probably acting through several mechanisms and thus CB2 represents an interesting and promising target in the chronic pain field. Further clarification of the mechanisms at the basis of CB2 analgesic effect would surely be an intriguing and stimulating area of research for the years to come.”

http://www.ncbi.nlm.nih.gov/pubmed/19358815

Cannabinoids and pain.

Abstract

“Recent advances have dramatically increased our understanding of cannabinoid pharmacology: the psychoactive constituents of Cannabis sativa have been isolated, synthetic cannabinoids described and an endocannabinoid system identified, together with its component receptors, ligands and their biochemistry. Strong laboratory evidence now underwrites anecdotal claims of cannabinoid analgesia in inflammatory and neuropathic pain. Sites of analgesic action have been identified in brain, spinal cord and the periphery, with the latter two presenting attractive targets for divorcing the analgesic and psychotrophic effects of cannabinoids. Clinical trials are now required, but are hindered by a paucity of cannabinoids of suitable bioavailability and therapeutic ratio.”

http://www.ncbi.nlm.nih.gov/pubmed/11575713

[The pharmacology of cannabinoid derivatives: are there applications to treatment of pain?].

“OBJECTIVE:

To present the cannabinoid system together with recent findings on the pharmacology of these compounds in the treatment of pain.

DATA SOURCES:

Search through Medline database of articles published in French and English since 1966. Also use of other publications such as books on cannabis.

DATA SYNTHESIS:

Recent advances have dramatically increased our understanding of cannabinoid pharmacology. The psychoactive constituents of Cannabis sativa have been isolated, synthetic cannabinoids described and an endocannabinoid system identified, together with its component receptors and ligands. Strong laboratory evidence now underwrites anecdotal claims of cannabinoid analgesia in inflammatory and neuropathic pain. Sites of analgesic action have been identified in brain, spinal cord and the periphery, with the latter two presenting attractive targets for divorcing the analgesic and psychotrophic effects of cannabinoids. Clinical trials are now required, but are hindered by a paucity of cannabinoids of suitable bioavailability and therapeutic ratio.

CONCLUSION:

The cannabinoid system is a major target in the treatment of pain and its therapeutic potential should be assessed in the near future by the performance of new clinical trials.”

http://www.ncbi.nlm.nih.gov/pubmed/12134594

Cannabinoid analgesia as a potential new therapeutic option in the treatment of chronic pain.

Abstract

“OBJECTIVE:

To review the literature concerning the physiology of the endocannabinoid system, current drug development of cannabinoid agonists, and current clinical research on the use of cannabinoid agonists for analgesia.

DATA SOURCES:

Articles were identified through a search of MEDLINE (1966-August 2005) using the key words cannabis, cannabinoid, cannabi*, cannabidiol, nabilone, THC, pain, and analgesia. No search limits were included. Additional references were located through review of the bibliographies of the articles identified.

STUDY SELECTION AND DATA EXTRACTION:

Studies of cannabinoid agonists for treatment of pain were selected and were not limited by pain type or etiology. Studies or reviews using animal models of pain were also included. Articles that related to the physiology and pharmacology of the endocannabinoid system were evaluated.

DATA SYNTHESIS:

The discovery of cannabinoid receptors and endogenous ligands for these receptors has led to increased drug development of cannabinoid agonists. New cannabimimetic agents have been associated with fewer systemic adverse effects than delta-9-tetrahydrocannabinol, including recent development of cannabis medicinal extracts for sublingual use (approved in Canada), and have had promising results for analgesia in initial human trials. Several synthetic cannabinoids have also been studied in humans, including 2 cannabinoid agonists available on the international market.

CONCLUSIONS:

Cannabinoids provide a potential approach to pain management with a novel therapeutic target and mechanism. Chronic pain often requires a polypharmaceutical approach to management, and cannabinoids are a potential addition to the arsenal of treatment options.”

http://www.ncbi.nlm.nih.gov/pubmed/16449552

Role of the Cannabinoid System in Pain Control and Therapeutic Implications for the Management of Acute and Chronic Pain Episodes

“Hemp, Cannabis sativa, is a coarse bushy annual plant with palmate leaves and clusters of small green flowers that grows wild in regions of mild or tropical weather and can attain a height of 3 metres. The genus name Cannabis is complemented by sativa (which means useful). Cannabis has indeed been used throughout history for a variety of purposes…

 Cannabis has been utilised for centuries throughout the world to alleviate disease. Its derivatives were named “panacea”, or “cure-all”, and were sold as a legal medicine, mainly for pain…

The discovery of cannabinoid receptors, their endogenous ligands, and the machinery for the synthesis, transport, and degradation of these retrograde messengers, has equipped us with neurochemical tools for novel drug design. Agonist-activated cannabinoid receptors, modulate nociceptive thresholds, inhibit release of pro-inflammatory molecules, and display synergistic effects with other systems that influence analgesia, especially the endogenous opioid system. Cannabinoid receptor agonists have shown therapeutic value against inflammatory and neuropathic pains, conditions that are often refractory to therapy…”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2430692/