Smoked cannabis proven effective in treating neuropathic pain.

UC San Diego Health

“Smoked cannabis eased pain induced in healthy volunteers, according to a study by researchers at the University of California, San Diego (UCSD) Center for Medical Cannabis Research (CMCR.) However, the researchers found that less may be more.”

“The results, showing a medium-dose (4% THC by weight) of cannabis to be an effective analgesic, converged with results from the CMCR’s first published study, a paper by UCSF researcher Donald Abrams, M.D. published in the journal Neurology in February 2007. In that randomized placebo-controlled trial, patients smoking the same dose of cannabis experienced a 34% reduction in HIV-associated sensory neuropathy pain—twice the rate experienced by patients receiving a placebo.”

““This study helps to build a case that cannabis does have therapeutic value at a medium-dose level,” said Grant. “It also suggests that higher doses aren’t necessarily better in certain situations – something also observed with other medications, such as antidepressants.””

Read more: http://phys.org/news112456382.html

“Smoked Cannabis Proven Effective In Treating Neuropathic Pain”  https://www.sciencedaily.com/releases/2007/10/071024141745.htm

“Smoked cannabis proven effective in treating neuropathic pain”  https://medicalxpress.com/news/2007-10-cannabis-proven-effective-neuropathic-pain.html

“Smoked Cannabis Proven Effective in Treating Neuropathic Pain”  https://health.ucsd.edu/news/2007/pages/10-24-medical-cannabis.aspx

Self-medication of a cannabinoid CB2 agonist in an animal model of neuropathic pain.

“Neuropathic pain is caused by injury to the peripheral or central nervous system (CNS)…”

“…novel approaches for identifying safe and effective analgesics with limited abuse liability are necessary.”

“Cannabinoids share the same target as the psychoactive ingredient in maijuana. Cannabinoids suppress neuropathic nociception through CB1 and CB2 mechanisms. CB1 is predominantly located within the CNS… CB2 activation is not associated with CNS side-effects linked to CB1. However, abuse potential of CB2 agonists is unknown.”

“We used a drug self-administration approach to ask whether rats with a spared nerve injury (SNI) would self-medicate with a CB2 agonist to attenuate a neuropathic pain state…”

 “Our results suggest that cannabinoid CB2 agonists may be exploited to treat neuropathic pain with limited drug abuse liability and central nervous system (CNS) side-effects. These studies validate the use of drug self-administration methods for identifying nonpsychotropic analgesics possessing limited abuse potential…”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3157548/

Role of cannabinoids in the management of neuropathic pain.

Abstract

“The treatment of pain, particularly neuropathic pain, is one of the therapeutic applications of cannabis and cannabinoids that is currently under investigation and that stimulates interest among clinicians and basic researchers. Animal pain models, including models of acute, antinociceptive, inflammatory and neuropathic pain, have demonstrated the antinociceptive efficacy of cannabinoids without causing serious alterations in animal behaviour. These data, together with the historic and current empiric use of cannabinoids, support the interest in the analysis of their effectiveness in treating neuropathic pain. The evaluation of controlled trials that focus on the effect of cannabinoids on neuropathic pain reveals that this class of drugs is able to significantly reduce pain perception. Nevertheless, this effect is generally weak and clinical relevance remains under evaluation. Moreover, there is a lack of controlled trials and, in particular, comparisons with other drugs generally used in the treatment of neuropathic pain. Despite the fact that further research is required to achieve a definitive assessment, current data obtained from basic research and from analysis of the available controlled trials indicate that cannabinoids can be accepted as a useful option in the treatment of neuropathic pain.”

http://www.ncbi.nlm.nih.gov/pubmed/18601303

More evidence cannabis can help in neuropathic pain.

“It’s good to see the trial of smoked cannabis in neuropathic pain reported by Ware and colleagues because smoking is the most common way in which patients try this drug. The authors should be congratulated for tackling the question of whether cannabis helps in neuropathic pain, particularly given that the regulatory hurdles for their trial must have been a nightmare. The question is worth investigating because of the ongoing publicity — which patients see, hear and read — that suggests an analgesic activity of cannabis in neuropathic pain, and because of the paucity of robust evidence for such an analgesic effect. If patients are not achieving a good response with conventional treatment of their pain, then they may, reasonably, wish to try cannabis. If medical cannabis is not available where a patient lives, then obtaining it will take the patient outside of the law, often for the first time in his or her life. Good evidence would at least buttress that decision.”

“This trial adds to the three previous studies of smoked cannabis in neuropathic pain that I could find using PubMed and reference lists…”

“Putting together the four trials of smoked cannabis, the provisional conclusions are that an analgesic effect is evident, that this effect, though not great, may be of use to some patients, and that it often carries with it some adverse effects on the central nervous system (though not obviously so in this trial). These conclusions make biological sense, given that cannabinoids taken orally have shown the same sorts of effects. Interestingly, the “moderate” analgesic effect shown here for neuropathic pain seems to hold true for nociceptive pain.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2950178/

Antihyperalgesic effect of a Cannabis sativa extract in a rat model of neuropathic pain: mechanisms involved.

Abstract

“This study aimed to give a rationale for the employment of phytocannabinoid formulations to treat neuropathic pain. It was found that a controlled cannabis extract, containing multiple cannabinoids, in a defined ratio, and other non-cannabinoid fractions (terpenes and flavonoids) provided better antinociceptive efficacy than the single cannabinoid given alone, when tested in a rat model of neuropathic pain. The results also demonstrated that such an antihyperalgesic effect did not involve the cannabinoid CB1 and CB2 receptors, whereas it was mediated by vanilloid receptors TRPV1. The non-psychoactive compound, cannabidiol, is the only component present at a high level in the extract able to bind to this receptor: thus cannabidiol was the drug responsible for the antinociceptive behaviour observed. In addition, the results showed that after chronic oral treatment with cannabis extract the hepatic total content of cytochrome P450 was strongly inhibited as well as the intestinal P-glycoprotein activity. It is suggested that the inhibition of hepatic metabolism determined an increased bioavailability of cannabidiol resulting in a greater effect. However, in the light of the well known antioxidant and antiinflammatory properties of terpenes and flavonoids which could significantly contribute to the therapeutic effects, it cannot be excluded that the synergism observed might be achieved also in the absence of the cytochrome P450 inhibition.”

http://www.ncbi.nlm.nih.gov/pubmed/18618522

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/

Multiple sclerosis and extract of cannabis: results of the MUSEC trial.

“Multiple sclerosis (MS) is associated with chronic symptoms, including muscle stiffness, spasms, pain and insomnia. Here we report the results of the Multiple Sclerosis and Extract of Cannabis (MUSEC) study that aimed to substantiate the patient based findings of previous studies.”

“CONCLUSION:

The study met its primary objective to demonstrate the superiority of cannabis extract (CE) over placebo in the treatment of muscle stiffness in MS. This was supported by results for secondary efficacy variables. Adverse events in participants treated with CE were consistent with the known side effects of cannabinoids. No new safety concerns were observed.”

http://www.ncbi.nlm.nih.gov/pubmed/22791906

Smoked cannabis for spasticity in multiple sclerosis: a randomized, placebo-controlled trial.

“Spasticity is a common and disabling symptom that remains a substantial problem for many patients with multiple sclerosis. Some patients have adverse effects from conventional antispasticity medications; for others, spasticity persists despite treatment. A report from the Institute of Medicine in the United States concluded that the active compounds of cannabis (marijuana) are potentially effective in treating neurologic conditions and “should be tested rigorously in clinical trials.” There is evidence that the cannabinoid receptors CB1 and CB2 may be involved in the control of spasticity in multiple sclerosis2 and that the endogenous ligand of CB1, anandamide, is itself an effective antispasticity agent.3 CB1 receptors are primarily presynaptic; their activation inhibits calcium influx and glutamate release, and reduces neuronal excitability by activating somatic and dendritic potassium channels.

“Although many patients with multiple sclerosis endorse smoking cannabis as therapy, evidence that it relieves spasticity is largely anecdotal, as most trials focus on orally administered cannabinoids. We sought to assess the safety and efficacy of smoked cannabis versus placebo in patients with multiple sclerosis who have treatment-resistant spasticity.”

“Smoked cannabis was superior to placebo in symptom and pain reduction in participants with treatment-resistant spasticity. Future studies should examine whether different doses can result in similar beneficial effects with less cognitive impact.”

“No serious adverse events occurred during the trial.”

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3394820/

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/

Efficacy, safety and tolerability of an orally administered cannabis extract in the treatment of spasticity in patients with multiple sclerosis: a randomized, double-blind, placebo-controlled, crossover study.

“OBJECTIVE:

Cannabis may alleviate some symptoms associated with multiple sclerosis (MS). This study investigated the effect of an orally administered standardized Cannabis sativa plant extract in MS patients with poorly controlled spasticity.”

“CONCLUSION:

A standardized Cannabis sativa plant extract might lower spasm frequency and increase mobility with tolerable side effects in MS patients with persistent spasticity not responding to other drugs.”

http://www.ncbi.nlm.nih.gov/pubmed/15327040