Smoked Medical Cannabis May Be Beneficial as Treatment for Chronic Neuropathic Pain, Study Suggests.

“Medicinal marijuana. A new study provides evidence that cannabis may offer relief to patients suffering from chronic neuropathic pain. (Credit: iStockphoto)”
 

“The medicinal use of cannabis has been debated by clinicians, researchers, legislators and the public at large for many years as an alternative to standard pharmaceutical treatments for pain, which may not always be effective and may have unwanted side effects. A new study by McGill University Health Centre (MUHC) and McGill University researchers provides evidence that cannabis may offer relief to patients suffering from chronic neuropathic pain.”

“This is the first trial to be conducted where patients have been allowed to smoke cannabis at home and to monitor their responses, daily,” says Dr. Mark Ware, lead author of the study, who is also Director of Clinical Research at the Alan Edwards Pain Management Unit at the MUHC and an assistant professor of anesthesia in McGill University’s Faculty of Medicine, and neuroscience researcher at the Research Institute of the MUHC.

In this study, low doses (25mg) of inhaled cannabis containing approximately 10% THC (the active ingredient in cannabis), smoked as a single inhalation using a pipe three times daily over a period of five days, offered modest pain reduction in patients suffering from chronic neuropathic pain (pain associated with nerve injury) within the first few days. The results also suggest that cannabis improved moods and helped patients sleep better. The effects were less pronounced in cannabis strains containing less than 10% THC.

“The patients we followed suffered from pain caused by injuries to the nervous system from post-traumatic (e.g. traffic accidents) or post-surgical (e.g. cut nerves) events, and which was not controlled using standard therapies” explains Dr. Ware. “This kind of pain occurs more frequently than many people recognize, and there are few effective treatments available. For these patients, medical cannabis is sometimes seen as their last hope.”

“This study marks an important step forward because it demonstrates the analgesic effects of cannabis at a low dose over a shot period of time for patients suffering from chronic neuropathic pain,” adds Dr. Ware. The study used herbal cannabis from Prairie Plant Systems (under contract to Health Canada to provide cannabis for research and medical purposes), and a 0% THC ‘placebo’ cannabis from the USA.”

Read more:http://www.sciencedaily.com/releases/2010/08/100830094926.htm

Analgesic effect of the synthetic cannabinoid CT-3 on chronic neuropathic pain: a randomized controlled trial.

“1′,1’dimethylheptyl-Delta8-tetrahydrocannabinol-11-oic acid (CT-3), a potent analog of THC-11-oic acid, produces marked antiallodynic and analgesic effects in animals without evoking the typical effects described in models of cannabinoids. Therefore, CT-3 may be an effective analgesic for poorly controlled resistant neuropathic pain.”

 

“OBJECTIVE: To examine the analgesic efficacy and safety of CT-3 in chronic neuropathic pain in humans.”

 

“CONCLUSIONS: In this preliminary study, CT-3 was effective in reducing chronic neuropathic pain compared with placebo. No major adverse effects were observed.”

 

http://www.ncbi.nlm.nih.gov/pubmed/14519710

Smoked Medicinal Cannabis for Neuropathic Pain in HIV: A Randomized, Crossover Clinical Trial.

“In 1999, a report of the United States Institute of Medicine recommended further investigations of the possible benefits of cannabis (marijuana) as a medicinal agent for a variety of conditions, including neuropathic pain due to HIV distal sensory polyneuropathy (DSPN). The most abundant active ingredient in cannabis, tetrahydro-cannabinol (THC), and its synthetic derivatives, produce effective analgesia in most animal models of pain. The antinociceptive effects of THC are mediated through cannabinoid receptors (CB1, CB2) in the central and peripheral nervous systems, which in turn interact with noradrenergic and κ-opioid systems in the spinal cord to modulate the perception of painful stimuli. The endogenous ligand of CB1, anandamide, itself is an effective antinociceptive agent. In open-label clinical trials and one recent controlled trial, medicinal cannabis has shown preliminary efficacy in relieving neuropathic pain.”

“We conducted a clinical trial to assess the impact of smoked cannabis on neuropathic pain in HIV. This was a phase II, double-blind, placebo-controlled, crossover trial of analgesia with smoked cannabis in HIV-associated distal sensory predominant polyneuropathy (DSPN).”

 “…pain relief was greater with cannabis than placebo…”

 “Smoked cannabis was generally well tolerated and effective when added to concomitant analgesic therapy in patients with medically refractory pain due to HIV DSPN.”

“Our findings suggest that cannabinoid therapy may be an effective option for pain relief in patients with medically intractable pain due to HIV-associated DSPN.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3066045/

Smoked cannabis for chronic neuropathic pain: a randomized controlled trial.

“Cannabis sativa has been used to treat pain since the third millennium BC. An endogenous pain-processing system has been identified, mediated by endogenous cannabinoid ligands acting on specific cannabinoid receptors.These findings, coupled with anecdotal evidence of the analgesic effects of smoked cannabis, support a reconsideration of cannabinoid agents as analgesics.”

“Oral cannabinoids such as tetrahydrocannabinol, cannabidiol and nabilone have, alone and in combination, shown efficacy in central and peripheral neuropathic pain, rheumatoid arthritis and fibromyalgia.”

“We conducted a clinical trial using a standardized single-dose delivery system to explore further the safety and efficacy of smoked cannabis in outpatients with chronic neuropathic pain.”

“Conclusion

A single inhalation of 25 mg of 9.4% tetrahydrocannabinol herbal cannabis three times daily for five days reduced the intensity of pain, improved sleep and was well tolerated.”

“Our results support the claim that smoked cannabis reduces pain, improves mood and helps sleep. We believe that our trial provides a methodological approach that may be considered for further research. Clinical studies using inhaled delivery systems, such as vaporizers, are needed.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2950205/

Low-Dose Vaporized Cannabis Significantly Improves Neuropathic Pain.

“We conducted a double-blind, placebo-controlled, crossover study evaluating the analgesic efficacy of vaporized cannabis in subjects, the majority of whom were experiencing neuropathic pain despite traditional treatment…”

“…cannabis has analgesic efficacy with the low dose being as effective a pain reliever as the medium dose. Psychoactive effects were minimal and well tolerated…”

“Vaporized cannabis, even at low doses, may present an effective option for patients with treatment-resistant neuropathic pain. PERSPECTIVE: The analgesia obtained from a low dose of delta-9-tetrahydrocannabinol (1.29%) in patients, most of whom were experiencing neuropathic pain despite conventional treatments, is a clinically significant outcome…”

http://www.ncbi.nlm.nih.gov/pubmed/23237736

Cannabis eases multiple sclerosis (MS) stiffness: study

“Use of cannabis extract helps ease painful muscle stiffness among patients with multiple sclerosis (MS), according to a large trial published on Tuesday in the Journal of Neurology, Neurosurgery and Psychiatry.

The “Phase III” test — the final stage in a process to vet a new drug or medical process — took place among 22 centres in Britain.

Over 12 weeks, 144 patients were given daily tablets of tetrahydrocannabinol, which is the active ingredient in cannabis, and 135 were given a dummy pill, also called a placebo…

…They also reported improvement in sleep quality. Side effects were nervous system disorders and gut problems, but none was severe…

The trial, led by John Peter Zajicek of Britain’s Clinical Neurology Research Group, says standardized doses of cannabis extract can be useful in easing pain and spasms in this disease.

Previous Phase III trials on cannabis and MS have thrown up conflicting results, partly because of the scale by which users report any change in their symptoms, the MUSEC researchers said.”

http://articles.nydailynews.com/2012-10-10/news/34367509_1_multiple-sclerosis-cannabis-nerve-cells

Medicinal cannabis extracts for the treatment of multiple sclerosis.

Abstract

“Prior to 2002, few clinical data were available to indicate whether cannabis extracts may be beneficial. However, in the last two years, results of several placebo-controlled clinical trials of orally administered compounds have been published, and these cast doubt on the efficacy of delta9-tetrahydrocannabinol (delta9-THC) in objectively reducing spasticity in MS. By contrast, it has been claimed that sublingually administered cannabis extracts that contain approximately equal concentrations of delta9-THC and cannabidiol, a natural cannabinoid that does not act on the CB1 receptor, can produce a statistically and clinically significant reduction in spasticity, although this claim has yet to be thoroughly validated. Nonetheless, results of preclinical trials also lend support to the hypothesis that the endogenous cannabinoid system may be involved in the regulation of spasticity and pain. A better indication of the clinical potential of the different cannabis extracts will have to await the publication of the most recent clinical trial data. This review critically evaluates the most recent evidence available on the potential use of medicinal extracts of cannabis to relieve pain and spasticity in multiple sclerosis.”

http://www.ncbi.nlm.nih.gov/pubmed/15298068

A preliminary controlled study to determine whether whole-plant cannabis extracts can improve intractable neurogenic symptoms.

“OBJECTIVES:

To determine whether plant-derived cannabis medicinal extracts (CME) can alleviate neurogenic symptoms unresponsive to standard treatment, and to quantify adverse effects.

SUBJECTS:

Twenty-four patients with multiple sclerosis (18), spinal cord injury (4), brachial plexus damage (1), and limb amputation due to neurofibromatosis (1).

INTERVENTION:

Whole-plant extracts of delta-9-tetrahydrocannabinol (THC), cannabidiol (CBD), 1:1 CBD:THC, or matched placebo were self-administered by sublingual spray at doses determined by titration against symptom relief or unwanted effects within the range of 2.5-120 mg/24 hours. Measures used: Patients recorded symptom, well-being and intoxication scores on a daily basis using visual analogue scales. At the end of each two-week period an observer rated severity and frequency of symptoms on numerical rating scales, administered standard measures of disability (Barthel Index), mood and cognition, and recorded adverse events.

RESULTS:

Pain relief associated with both THC and CBD was significantly superior to placebo. Impaired bladder control, muscle spasms and spasticity were improved by CME in some patients with these symptoms. Three patients had transient hypotension and intoxication with rapid initial dosing of THC-containing CME.

CONCLUSIONS:

Cannabis medicinal extracts can improve neurogenic symptoms unresponsive to standard treatments. Unwanted effects are predictable and generally well tolerated. Larger scale studies are warranted to confirm these findings.”

http://www.ncbi.nlm.nih.gov/pubmed/12617376

Whole plant cannabis extracts in the treatment of spasticity in multiple sclerosis: a systematic review.

“Spasticity, an involuntary increase in muscle tone or rapid muscle contractions, is one of the more common and distressing symptoms of multiple sclerosis (MS). Medicinal treatment may reduce spasticity, but may also be ineffective, difficult to obtain, or associated with intolerable side effects. Cannabis, a psychotropic drug known for its analgesic properties, also has a long history as an effective and tolerable treatment for spasticity]. Demographic evidence has shown that many people with MS use cannabis for symptom management.

Clinical studies, animal models, and anecdotal reports have suggested that cannabis may be an effective treatment of MS spasticity. The antispastic effect of cannabis has been supported through a demonstration of the inhibitory properties in exogenous agonists for cannabis receptors found in the CNS. Early clinical trials reporting the efficacy and safety of cannabis use in MS have focused on the effects of Δ9-tetrahydrocannabinol (THC). Although these clinical studies reported a therapeutic benefit for MS symptoms, there were concerns of potential intoxication and other side effects of cannabis-based treatment. Another clinical study using a cannabidiol (CBD) extract documented a reduction in spasticity-related pain but not in spasticity..

More recent combination therapies using whole plant extracts of both THC and CBD have been introduced and there is evidence that CBD, which is not psychotropic, may reduce THC levels in the brain and attenuate its psychotropic side effects. Such therapies may potentially provide a tolerable yet effective treatment for MS symptoms. A number of recent studies have investigated the potential efficacy and safety of whole plant extracts of THC and CBD. One of the first large-scale studies of cannabis treatment for MS-related spasticity compared whole plant cannabis extracts with THC and a placebo, and found mixed evidence for the therapeutic benefit of spasticity in MS. A recent review that included a number of these recent studies provided additional support for the benefit of cannabinoids in MS-related spasticity but called for further study into long-term treatment and side effects. A systematic evaluation of recent research had not previously been conducted, and was needed in order to provide organized evidence of cannabinoid treatments and direction for future clinical studies. We therefore systematically reviewed studies that used a combination extract of THC and CBD for the treatment of spasticity.

We found evidence that combined THC and CBD extracts may provide therapeutic benefit for MS spasticity symptoms…

Finally, there is evidence that cannabinoids may provide neuroprotective and anti-inflammatory benefits in MS. Neuroinflammation, found in autoimmune diseases such as MS, has been shown to be reduced by cannabinoids through the regulation of cytokine levels in microglial cells. The therapeutic potential of cannabinoids in MS is therefore comprehensive and should be given considerable attention.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2793241/

Randomized, controlled trial of cannabis-based medicine in central pain in multiple sclerosis.

“Central pain in multiple sclerosis (MS) is common and often refractory to treatment…

We conducted a single-center, 5-week (1-week run-in, 4-week treatment), randomized, double-blind, placebo-controlled, parallel-group trial in 66 patients with MS and central pain states (59 dysesthetic, seven painful spasms) of a whole-plant cannabis-based medicine (CBM), containing delta-9-tetrahydrocannabinol:cannabidiol (THC:CBD) delivered via an oromucosal spray, as adjunctive analgesic treatment…

CONCLUSIONS:

Cannabis-based medicine is effective in reducing pain and sleep disturbance in patients with multiple sclerosis related central neuropathic pain and is mostly well tolerated.”

http://www.ncbi.nlm.nih.gov/pubmed/16186518