Category Archives: Pain

Safety and Efficacy of Medical Cannabis in Fibromyalgia

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jcm-logo“Chronic pain may be treated by medical cannabis. Yet, there is scarce evidence to support the role of medical cannabis in the treatment of fibromyalgia. The aim of the study was to investigate the characteristics, safety, and effectiveness of medical cannabis therapy for fibromyalgia.

Results: Among the 367 fibromyalgia patients, the mean age was 52.9 ± 15.1, of whom 301 (82.0%) were women. Twenty eight patients (7.6%) stopped the treatment prior to the six months follow-up. The six months response rate was 70.8%. Pain intensity (scale 0–10) reduced from a median of 9.0 at baseline to 5.0 (p < 0.001), and 194 patients (81.1%) achieved treatment response. In a multivariate analysis, age above 60 years (odds ratio [OR] 0.34, 95% C.I 0.16–0.72), concerns about cannabis treatment (OR 0.36, 95% C.I 0.16–0.80), spasticity (OR 2.26, 95% C.I 1.08–4.72), and previous use of cannabis (OR 2.46 95% C.I 1.06–5.74) were associated with treatment outcome. The most common adverse effects were mild and included dizziness (7.9%), dry mouth (6.7%), and gastrointestinal symptoms (5.4%).

Conclusion: Medical cannabis appears to be a safe and effective alternative for the treatment of fibromyalgia symptoms. Standardization of treatment compounds and regimens are required.”

https://www.mdpi.com/2077-0383/8/6/807

“Medical cannabis appears to be a safe and effective alternative for the treatment of fibromyalgia symptoms.”  https://www.ncbi.nlm.nih.gov/pubmed/31195754

Biosynthesis of cannflavins A and B from Cannabis sativa L.

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Phytochemistry

“In addition to the psychoactive constituents that are typically associated with Cannabis sativa L., there exist numerous other specialized metabolites in this plant that are believed to contribute to its medicinal versatility. This study focused on two such compounds, known as cannflavin A and cannflavin B. These prenylated flavonoids specifically accumulate in C. sativa and are known to exhibit potent anti-inflammatory activity in various animal cell models. However, almost nothing is known about their biosynthesis. Using a combination of phylogenomic and biochemical approaches, an aromatic prenyltransferase from C. sativa (CsPT3) was identified that catalyzes the regiospecific addition of either geranyl diphosphate (GPP) or dimethylallyl diphosphate (DMAPP) to the methylated flavone, chrysoeriol, to produce cannflavins A and B, respectively. Further evidence is presented for an O-methyltransferase (CsOMT21) encoded within the C. sativa genome that specifically converts the widespread plant flavone known as luteolin to chrysoeriol, both of which accumulate in C. sativa. These results therefore imply the following reaction sequence for cannflavins A and B biosynthesis: luteolin ► chrysoeriol ► cannflavin A and cannflavin B. Taken together, the identification of these two unique enzymes represent a branch point from the general flavonoid pathway in C. sativa and offer a tractable route towards metabolic engineering strategies that are designed to produce these two medicinally relevant Cannabis compounds.”

https://www.ncbi.nlm.nih.gov/pubmed/31151063

https://www.sciencedirect.com/science/article/pii/S0031942218303819?via%3Dihub

“U of G Researchers First to Unlock Access to Pain Relief Potential of Cannabis”  https://news.uoguelph.ca/2019/07/u-of-g%E2%80%AFresearchers-first-to-unlock-access-to-pain%E2%80%AFrelief%E2%80%AFpotential-of-cannabis%E2%80%AF/

“Scientists unlock the secrets of marijuana’s pain-relief potential, study says” HTTPS://WWW.NEWSOBSERVER.COM/NEWS/NATION-WORLD/NATIONAL/ARTICLE233045517.HTML

Cannabidiol, cannabinol and their combinations act as peripheral analgesics in a rat model of myofascial pain.

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Archives of Oral Biology

“This study investigated whether local intramuscular injection of non-psychoactive cannabinoids, cannabidiol (CBD), cannabinol (CBN), cannabichromene (CBC) and their combinations can decrease nerve growth factor (NGF)-induced masticatory muscle sensitization in female rats.

RESULTS:

In behavioral experiments, CBD (5 mg/ml) or CBN (1 mg/ml) decreased NGF-induced mechanical sensitization. Combinations of CBD/CBN induced a longer-lasting reduction of mechanical sensitization than either compound alone. No significant change in mechanical withdrawal threshold was observed in the contralateral masseter muscles and no impairment of motor function was found with the inverted screen test after any of the treatments. Consistent with behavioral results, CBD (5 mg/ml), CBN (1 mg/ml) and the combination of CBD/CBN (1:1 mg/ml) increased the mechanical threshold of masseter muscle mechanoreceptors. However, combining CBD/CBN (5:1 mg/ml) at a higher ratio reduced the duration of this effect. This may indicate an inhibitory effect of higher concentrations of CBD on CBN.

CONCLUSIONS:

These results suggest that peripheral application of these non-psychoactive cannabinoids may provide analgesic relief for chronic muscle pain disorders such as temporomandibular disorders and fibromyalgia without central side effects.”

https://www.ncbi.nlm.nih.gov/pubmed/31158702

https://www.sciencedirect.com/science/article/pii/S0003996919302249?via%3Dihub

Medical Cannabis: Effects on Opioid and Benzodiazepine Requirements for Pain Control.

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SAGE Journals

“The objective of this study was to determine if the use of medical cannabis affects the amount of opioids and benzodiazepines used by patients on a daily basis.

METHODS:

This single-center, retrospective cohort study evaluated opioid and benzodiazepine doses over a 6-month time period for patients certified to use medical cannabis for intractable pain. All available daily milligram morphine equivalents (MMEs) and daily diazepam equivalents (DEs) were calculated at baseline and at 3 and 6 months.

RESULTS:

A total of 77 patients were included in the final analysis. There was a statistically significant decrease in median MME from baseline to 3 months (-32.5 mg; P = 0.013) and 6 months (-39.1 mg; P = 0.001). Additionally, there was a non-statistically significant decrease in median DE at 3 months (-3.75 mg; P = 0.285) and no change in median DE from baseline to 6 months (-0 mg; P = 0.833). Conclusion and Relevance: Over the course of this 6-month retrospective study, patients using medical cannabis for intractable pain experienced a significant reduction in the number of MMEs available to use for pain control. No significant difference was noted in DE from baseline. Further prospective studies are warranted to confirm or deny the opioid-sparing effects of medical cannabis when used to treat intractable pain.”

https://www.ncbi.nlm.nih.gov/pubmed/31129977

https://journals.sagepub.com/doi/abs/10.1177/1060028019854221?journalCode=aopd

Age-related differences in Δ⁹-tetrahydrocannabinol-induced antinociception in female and male rats.

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Cover image for Experimental and Clinical Psychopharmacology

“Given the use of cannabis as an analgesic by a broadening age range of patients, the aim of this study was to determine whether the antinociceptive effects of Δ9-tetrahydrocannabinol (THC) differ by age.

On the tail withdrawal test, THC was significantly more effective in middle-aged adult than in young adult rats and significantly less effective in adolescent than in young adult rats.

Sex differences in THC’s antinociceptive effects were consistent across the 3 ages examined, with greater THC effects observed in females than males of each age. Age-related differences in THC’s locomotor-suppressing effect were also observed, with the greatest effect in young adult female rats. Serum THC levels were slightly higher in adolescent than in young adult rats, and levels of the active metabolites 11-OH-THC and cannabinol, as well as the inactive metabolite 11-nor-9-carboxy-THC, did not differ between adolescent and young adult rats.

These results suggest that the pain-relieving effects of THC may be more limited in adolescents than in adults and that these age-related differences in THC effect are not attributable to differential absorption or metabolism of THC.”

https://www.ncbi.nlm.nih.gov/pubmed/31120286

https://psycnet.apa.org/doiLanding?doi=10.1037%2Fpha0000257

Effects of cannabinoid administration for pain: A meta-analysis and meta-regression.

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APA's header logo

“Chronic pain states have resulted in an overreliance on opioid pain relievers, which can carry significant risks when used long term. As such, alternative pain treatments are increasingly desired.

Although emerging research suggests that cannabinoids have therapeutic potential regarding pain, results from studies across pain populations have been inconsistent. To provide meta-analytic clarification regarding cannabis’s impact on subjective pain, we identified studies that assessed drug-induced pain modulations under cannabinoid and corresponding placebo conditions.

Results revealed that cannabinoid administration produced a medium-to-large effect across included studies, Cohen’s d = -0.58, 95% confidence interval (CI) [-0.74, -0.43], while placebo administration produced a small-to-medium effect, Cohen’s d = -0.39, 95% CI [-0.52, -0.26]. Meta-regression revealed that cannabinoids, β = -0.43, 95% CI [-0.62, -0.24], p < .05, synthetic cannabinoids, β = -0.39, 95% CI [-0.65, -0.14], p < .05, and sample size, β = 0.01, 95% CI [0.00, 0.01], p < .05, were associated with marked pain reduction.

These outcomes suggest that cannabinoid-based pharmacotherapies may serve as effective replacement/adjunctive options regarding pain, however, additional research is warranted.”

https://www.ncbi.nlm.nih.gov/pubmed/31120281

https://psycnet.apa.org/doiLanding?doi=10.1037%2Fpha0000281

Supplementation of Cannabis sativa L. leaf powder accelerates functional recovery and ameliorates haemoglobin level following an induced injury to sciatic nerve in mouse model.

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Image result for Pak J Pharm Sci.

“Peripheral nerve injury is a common condition with a multitude of signs and symptoms. The major consequence of injury is limited physical activity. Presently, we are lacking effective therapies for PNI and it is need of the hour is to explore potential remedies for the recovery of functional loss.

Here, we have investigated the role of crude Cannabis sativa L. leaf powder in promoting functions recovery, in mouse model subjected to a traumatic sciatic nerve injury.

A dose of 200mg/kg of the body weight per day was administered orally from the day of nerve crush till the end of the experiment. The motor functions were evaluated by measuring sciatic functional index, muscle grip strength and muscle mass; whereas the sensory functions were assessed by hotplate test. The haematology and serum analyses were carried out to estimate the effect of treatment on the systemic index and oxidative stress.

The gain of motor functions was significantly improved and was early noticed in the treated mice. Restoration of muscle mass and elevated haemoglobin level were statistically significant in the treatment group.

This study indicates that Cannabis sativa L. supplementation accelerates the motor functions recovery after nerve compression injury.”

https://www.ncbi.nlm.nih.gov/pubmed/31103973

CB2 receptor deletion on myeloid cells enhanced mechanical allodynia in a mouse model of neuropathic pain.

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 Scientific Reports“Neuropathic pain can develop after nerve injury, leading to a chronic condition with spontaneous pain and hyperalgesia.

Pain is typically restricted to the side of the injured nerve, but may occasionally spread to the contralateral side, a condition that is often referred to as mirror-image pain.

Mechanisms leading to mirror-image pain are not completely understood, but cannabinoid CB2 receptors have been implicated.

In this study, we use genetic mouse models to address the question if CB2 receptors on neurons or on microglia/macrophages are involved.

We conclude that CB2 receptors on microglia and macrophages, but not on neurons, modulate neuropathic pain responses.”

https://www.ncbi.nlm.nih.gov/pubmed/31097758

https://www.nature.com/articles/s41598-019-43858-4

Diverse TRPV1 responses to cannabinoids.

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 Publication Cover“Cannabinoid compounds are potential analgesics. Users of medicinal Cannabis report efficacy for pain control, clinical studies show that cannabis can be effective and opioid sparing in chronic pain, and some constituent cannabinoids have been shown to target nociceptive ion channels. Here, we explore and compare a suite of cannabinoids for their impact upon the physiology of TRPV1. The cannabinoids tested evoke differential responses in terms of kinetics of activation and inactivation. Cannabinoid activation of TRPV1 displays significant dependence on internal and external calcium levels. Cannabinoid activation of TRPV1 does not appear to induce the highly permeant, pore-dilated channel state seen with Capsaicin, even at high current amplitudes. Finally, we analyzed cannabinoid responses at nocioceptive channels other than TRPV1 (TRPV2, TRPM8 and TRPA1), and report that cannabinoids differentially activate these channels. On the basis of response activation and kinetics, state-selectivity and receptor selectivity, it may be possible to rationally design approaches to pain using single or multiple cannabinoids.”

https://www.ncbi.nlm.nih.gov/pubmed/31096838

https://www.tandfonline.com/doi/full/10.1080/19336950.2019.1619436

Cannabinoid interactions with ion channels and receptors.

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Publication Cover

“Cannabidiol (CBD), the non-psychoactive component of Cannabis sativa, acts on a diverse selection of membrane proteins with promising therapeutic potential in epilepsy and chronic pain. In this review, we will outline the studies that report reproducible results of CBD and other cannabinoids changing membrane channel function, with particular interest on Nav. Nav are implicated in fatal forms of epilepsy and are also associated with chronic pain. This makes Nav potential targets for CBD interaction since it has been reported to reduce pain and seizures. This discovery will not only prompt further research towards CBD’s characterization, but also promotes the application of cannabinoids as potentially therapeutic compounds for diseases like epilepsy and pain.” https://www.ncbi.nlm.nih.gov/pubmed/31088312
https://www.tandfonline.com/doi/full/10.1080/19336950.2019.1615824