Category Archives: Chronic Inflammatory and Neuropathic Pain

Cannabidiol attenuates hypersensitivity and oxidative stress after traumatic spinal cord injury in rats

Posted on by
Reply
Neuroscience Letters

“Neuropathic pain (NP) arises as a direct consequence of traumatic spinal cord injury (SCI), which leads to devastating consequences for people suffering from this condition since no specific treatment has been defined. One relevant mechanism in generating painful stimuli involves the direct participation of reactive oxygen species (ROS) at the cellular and subcellular levels.

Cannabidiol (CBD) is one of the two most crucial cannabinoid components of the cannabis plant and has been proposed as a potential treatment for NP. Its antioxidant, neuroprotective and anti-inflammatory properties have been documented. However, there is insufficient evidence regarding CBD as treatment of NP induced by SCI or the mechanisms that underlie this effect.

In this study, we evaluated the antinociceptive effect of CBD as an acute treatment after the nociceptive behaviors characteristic of NP were established (hypersensitivity threshold and hypersensitivity response). Furthermore, the participation of oxidative stress was determined by lipid peroxidation (LP) and glutathione concentration (GSH) in female Wistar rats with SCI.

Acute treatment with CBD (2.5-20 mg/kg, i.p.) decreased nociceptive behaviors in a dose-dependent manner, decreased LP, and increased GSH concentration in injured tissue 15 days after injury. The findings of this study suggest that the antinociceptive effect induced by CBD is regulated by reducing oxidative stress by decreasing the LP and increasing the concentration of antioxidant (GSH) defenses.”

https://pubmed.ncbi.nlm.nih.gov/36028005/

“Cannabidiol decreases hyperalgesia in a dose–response manner after spinal cord injury.”

https://www.sciencedirect.com/science/article/abs/pii/S0304394022004165?via%3Dihub

Cannabidiol enhances the antinociceptive effects of morphine and attenuates opioid-induced tolerance in the chronic constriction injury model

Posted on by
Reply
Behavioural Brain Research

“Neuropathic pain (NP) is a complex health problem that includes sensorial manifestations such as evoked and ongoing pain. Cannabidiol (CBD) has shown potential in the treatment of NP and the combination between opioids and cannabinoids has provided promising results on pain relief. Thus, our study aimed to investigate the effect of treatment combination between CBD and morphine on evoked and ongoing pain, and the effect of CBD on morphine-induced tolerance in the model of chronic constriction injury (CCI) of the sciatic nerve in rats.

Mechanical thresholds (i.e., evoked pain) were evaluated before and 7 days after surgery. We also employed a 4-day conditioned place preference (CPP) protocol, to evaluate relief of ongoing pain (6 to 9 days after surgery). Treatment with morphine (2 and 4mg/kg) or CBD (30mg/kg) induced a significant antinociceptive effect on evoked pain.

The combination of CBD (30mg/kg) and morphine (1mg/kg) produced an enhanced antinociceptive effect, when compared to morphine alone (1mg/Kg). Treatment with morphine (1 and 2mg/kg) or CBD (30mg/kg) alone failed to induce significant scores in the CPP test. However, combined treatment of CBD (30mg/kg) and morphine (1mg/kg) provided significant positive scores, increased the number of entrances in the drug-paired chamber in the CPP test and did not alter locomotor activity in rats. Lastly, treatment with CBD partially attenuated morphine-induced tolerance.

In summary, our results support the indication of CBD as an adjuvant to opioid therapy for the attenuation of NP and opioid-induced analgesic tolerance.”

https://pubmed.ncbi.nlm.nih.gov/36028000/

“Taken together, the present results demonstrate that CBD or morphine exert antinociceptive effects in both mechanically evoked pain and ongoing pain after CCI in rats. The treatment combination of CBD and a sub-therapeutic dose of morphine, provided marked antinociceptive effects in both evoked and ongoing pain.”

https://www.sciencedirect.com/science/article/abs/pii/S0166432822003448?via%3Dihub

Cannabinoids Lead to Significant Improvement in Gastroparesis—Related Abdominal Pain

Posted on by
Reply

“Neuropathy plays a large role in the pathogenesis of gastroparesis. Neuropathic pain in gastroparesis is an often difficult—to—treat symptom of the disease, despite 80—90% of patients with gastroparesis reporting abdominal pain as a symptom. Treatment for gastroparesis—related pain is especially limited. Neuromodulators are used for this purpose despite a lack of evidence supporting their effectiveness.

Cannabinoids, primarily delta—9—tetrahydrocannabinol (THC) and cannabidiol (CBD), are increasingly utilized for medicinal purposes. In New York medical marijuana is approved for the treatment of neuropathy with severe pain. Similarly, Dronabinol (a synthetic THC analogue) has been used for nausea vomiting and anorexia for years.

We showed that cannabinoids are effective in the treatment of gastroparesis—related abdominal pain.”

“Conclusion: Our study shows that cannabinoids may play an important role in the management of gastroparesis—related abdominal pain. There are currently no treatments shown to be effective for gastroparetic pain in clinical trials, and cannabinoids may serve a niche for this under—treated symptom.”

https://journals.lww.com/ajg/fulltext/2018/10001/cannabinoids_lead_to_significant_improvement_in.1204.aspx

Medical Cannabis Certification Is Associated With Decreased Opiate Use in Patients With Chronic Pain: A Retrospective Cohort Study in Delaware

Posted on by
Reply
Cureus Competition Winners Announced - Synaptive Medical

“Opioid medications are commonly used to treat chronic pain around the world. While these medications are quite effective at reducing pain, they can create opioid dependence and lead to further drug addiction. Long-term opioid use has significantly contributed to the “opioid epidemic” that is currently ravaging the United States, leading to opioid overdoses and unintentional deaths, particularly in Delaware.

Objective To determine if medical marijuana certification helps patients in Delaware with chronic pain reduce their opiate use.

Methods In this study, we examined individuals who were provided with legal; medical cannabis certifications in the state of Delaware between June 2018 and October 2019 and were concurrently being treated with opioid medications for chronic pain at a private pain management practice. Using a posthoc analysis, we conducted a retrospective cohort study on the individuals (n = 81) to determine if there was a decrease in their opioid use following medical cannabis certification. Opioid use was measured in morphine milligram equivalent (MME) through the Delaware prescription monitoring program (PMP) database.

Results Overall, the average change in prescribed opioid use was found to be -12.3 morphine milligram equivalent (MME) units when including all individuals (p < 0.00001). Among the included individuals with baseline opioid use, medical cannabis certification was associated with a 31.3% average decrease in opioid use (n = 63). When examining subgroups based upon pain location, individuals with neck pain displayed a 41.5% average decrease in MME (n = 27), while individuals with low back pain were observed to have a 29.4% decrease in opioid use (n = 58). Similarly, individuals with knee pain (n = 14) reduced their opioid use by 32.6%.

Conclusion The results display an association between medical cannabis certification and a decrease in opiate use among the study group individuals. This study suggests that medical cannabis use may help individuals to reduce their opiate requirements along with physician intervention. More research is needed to validate these findings with appropriate controls and verification of cannabis use.”

https://pubmed.ncbi.nlm.nih.gov/35004055/

“The results of this study indicate that medical marijuana certification is associated with a decrease in prescription opiate use for chronic pain treatment and supports greater use of this adjunct treatment modality. Given the significance of opioid addiction in American society, any treatment or additional resource to reduce opioid overuse can aid in the multifactorial management of chronic pain. Although marijuana use causes a variety of side effects, the findings here suggest that the use of medical cannabis as an adjunct treatment for chronic pain may be beneficial to public health.”

https://www.cureus.com/articles/77114-medical-cannabis-certification-is-associated-with-decreased-opiate-use-in-patients-with-chronic-pain-a-retrospective-cohort-study-in-delaware

Treatments perceived to be helpful for neuropathic pain after traumatic spinal cord injury: A multicenter cross-sectional survey study

Posted on by
Reply
Publication Cover

“Objective: To evaluate the perceived helpfulness of pharmacological and non-pharmacological interventions and their combinations for neuropathic pain (NeuP) and subcategories of NeuP after spinal cord injury (SCI).

Methods: Three hundred ninety one individuals at least one year post traumatic SCI were enrolled. A telephone survey was conducted to determine the pharmacologic and non-pharmacologic treatments used in the last 12 months for each participant’s three worst pains, whether these treatments were “helpful”, and if currently used, each treatments’ effectiveness.

Results: Two hundred twenty participants (56%) reported 354 distinct NeuPs. Pharmacological treatments rated helpful for NeuP were non-tramadol opioids (opioids were helpful for 86% of opioid treated NeuPs), cannabinoids (83%), and anti-epileptics (79%). Non-pharmacological treatments rated helpful for NeuP were massage (76%), body position adjustment (74%), and relaxation therapy (70%). Those who used both opioids and exercise reported greater NeuP treatment helpfulness compared to participants using opioids without exercise (P = 0.03).

Conclusions: Opioids, cannabinoids, and massage were reported more commonly as helpful than treatments recommended as first-line therapies by current clinical practice guidelines (CPGs) for NeuP after SCI (antiepileptics and antidepressants). Individuals with SCI likely value the modulating effects of pharmacological and non-pharmacological treatments on the affective components of pain in addition to the sensory components of pain when appraising treatment helpfulness.”

https://pubmed.ncbi.nlm.nih.gov/35993799/

https://www.tandfonline.com/doi/full/10.1080/10790268.2022.2108665?scroll=top&needAccess=true

Benefits and Concerns Regarding Use of Cannabis for Therapeutic Purposes Among People Living with Chronic Pain: A Qualitative Research Study

Posted on by
Reply
Pain Medicine

“Objective: Although there is growing interest in medically authorized cannabis for chronic pain, little is known about patients’ perspectives. We explored perceptions of people living with chronic pain regarding benefits and concerns surrounding their use of cannabis for therapeutic purposes.

Setting: A hospital-based clinic in Hamilton and two community-based interdisciplinary pain clinics in Burlington, Ontario, Canada.

Methods: In this qualitative descriptive study, we conducted semi-structured interviews with 13 people living with chronic pain who used cannabis therapeutically, living in Ontario, Canada. We used thematic analysis, with data collection, coding, and analysis occurring concurrently.

Results: People living with chronic pain reported important benefits associated with use of cannabis for therapeutic purposes, including reduced pain, improved functionality, and less risk of harms compared to prescription opioids. Most patients also acknowledged harms, such as grogginess and coughing, and there was considerable variability in patient experiences. Financial costs and stigma were identified as important barriers to use of cannabis.

Conclusion: Evidence-based guidance that incorporates patients’ values and preferences may be helpful to inform the role of cannabis in the management of chronic pain.”

https://pubmed.ncbi.nlm.nih.gov/35652734/

https://academic.oup.com/painmedicine/advance-article-abstract/doi/10.1093/pm/pnac085/6598805?redirectedFrom=fulltext&login=false


Structural basis for cannabinoid-induced potentiation of alpha1-glycine receptors in lipid nanodiscs

Posted on by
Reply
Nature Communications

“Nociception and motor coordination are critically governed by glycine receptor (GlyR) function at inhibitory synapses. Consequentially, GlyRs are attractive targets in the management of chronic pain and in the treatment of several neurological disorders. High-resolution mechanistic details of GlyR function and its modulation are just emerging.

While it has been known that cannabinoids such as Δ9-tetrahydrocannabinol (THC), the principal psychoactive constituent in marijuana, potentiate GlyR in the therapeutically relevant concentration range, the molecular mechanism underlying this effect is still not understood.

Here, we present Cryo-EM structures of full-length GlyR reconstituted into lipid nanodisc in complex with THC under varying concentrations of glycine. The GlyR-THC complexes are captured in multiple conformational states that reveal the basis for THC-mediated potentiation, manifested as different extents of opening at the level of the channel pore.

Taken together, these structural findings, combined with molecular dynamics simulations and functional analysis, provide insights into the potential THC binding site and the allosteric coupling to the channel pore.”

https://pubmed.ncbi.nlm.nih.gov/35982060/

https://www.nature.com/articles/s41467-022-32594-5

Intrathecal Actions of the Cannabis Constituents Δ(9)-Tetrahydrocannabinol and Cannabidiol in a Mouse Neuropathic Pain Model

Posted on by
Reply
ijms-logo

“Background: The psychoactive and non-psychoactive constituents of cannabis, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), synergistically reduce allodynia in various animal models of neuropathic pain. Unfortunately, THC-containing drugs also produce substantial side-effects when administered systemically. We examined the effectiveness of targeted spinal delivery of these cannabis constituents, alone and in combination.

Methods: The effect of acute intrathecal drug delivery on allodynia and common cannabinoid-like side-effects was examined in a mouse chronic constriction injury (CCI) model of neuropathic pain.

Results: intrathecal THC and CBD produced dose-dependent reductions in mechanical and cold allodynia. In a 1:1 combination, they synergistically reduced mechanical and cold allodynia, with a two-fold increase in potency compared to their predicted additive effect. Neither THC, CBD nor combination THC:CBD produced any cannabis-like side-effects at equivalent doses. The anti-allodynic effects of THC were abolished and partly reduced by cannabinoid CB1 and CB2 receptor antagonists AM281 and AM630, respectively. The anti-allodynic effects of CBD were partly reduced by AM630.

Conclusions: these findings indicate that intrathecal THC and CBD, individually and in combination, could provide a safe and effective treatment for nerve injury induced neuropathic pain.”

https://pubmed.ncbi.nlm.nih.gov/35955774/

“The present findings indicate that intrathecal delivery of the phytocannabinoids THC and CBD reduces the mechanical and cold allodynia associated with a nerve injury induced model of neuropathic pain. Interestingly, THC and CBD acted synergistically to reduce allodynia, leading to a substantial increase in their anti-allodynic potency. In addition, both THC and CBD were devoid of the cannabis-like side-effects associated with the systemic delivery of THC-containing cannabinoids. These findings indicate that spinal delivery of the primary phytocannabinoids of the plant Cannabis sativa has potential in the treatment of chronic neuropathic pain.”

https://www.mdpi.com/1422-0067/23/15/8649/htm

Medicinal Cannabis for the Treatment of Chronic Refractory Pain: An Investigation of the Adverse Event Profile and Health-Related Quality of Life Impact of an Oral Formulation

Posted on by
Reply
Karger Publishers Further Expands into Open Access and Open Science | STM Publishing News

“Introduction: Medicinal cannabis is prescribed in Australia for patients with chronic refractory pain conditions. However, measures of safety and effectiveness of different cannabinoids are lacking. We designed an observational study to capture effectiveness, adverse events (AEs), and health-related quality of life (HRQoL) measures in patients prescribed an oral medicinal cannabis formulation at Cannabis Access Clinics through the Cannabis Access Clinics Observational study (CACOS).

Objectives: We aimed to evaluate effectiveness, reported AEs, and change in patient-reported outcomes in individuals prescribed a cannabinoid oil formulation for management of chronic pain.

Methods: A cross-sectional analysis was conducted on patients prescribed an oil formulation of Δ9-tetrahydrocannabinol and cannabidiol for pain symptoms of at least 3-month duration. Clinician-reported AEs were organized by system, organ, class, and frequency. Analysis of patient-reported responses to a questionnaire was conducted using published minimal clinically important differences to determine meaningful change in HRQoL over time.

Results: More than half (n = 91/151, 60.3%) of the participants experienced at least one AE during the observation period (mean 133 ± 116 days). No serious AEs were reported. Patient-reported pain impact scores were significantly reduced across the cohort (p = 0.034), and pain intensity scores verged on significance (p = 0.053). The majority of patients saw meaningful improvements in sleep (49.3%) and fatigue (35.6%).

Conclusion: This analysis presents real-world data collected as part of standard of care. More than one-third of patients benefited from oral medicinal cannabis, which is impactful given the refractory nature of their pain. Amelioration of the impact of pain confirms continued prescribing of this formulation and validates our observational methodology as a tool to determine the therapeutic potency of medicinal cannabinoids.”

https://pubmed.ncbi.nlm.nih.gov/35950052/

“This is a clinically relevant finding considering that this patient cohort comprises refractory cases where relief has not been obtained with existing medications, including opioids, NSAIDs, and steroids.”

https://www.karger.com/Article/FullText/521492

Medical Cannabis Used as an Alternative Treatment for Chronic Pain Demonstrates Reduction in Chronic Opioid Use – A Prospective Study

Posted on by
Reply
Pain Physician:::::

“Background: Chronic opioid therapy (COT) has been used to treat many chronic pain conditions even with poor evidence for its long-term effectiveness. Medical cannabis has emerged with certain pain-relieving properties, which has led to questions as to its’ potential application, especially in relation to its effect on opioid use.

Objectives: This study investigates a proposed clinical context in offering medical cannabis as a treatment for chronic pain for those already using chronic opioid therapy. It then details patients’ daily morphine milligram equivalent (MME) usage.

Study design: This single-center prospective study follows a group of patients trialing medical cannabis treatment for chronic pain that is already using COT in order to determine individual efficacy. Continued medical cannabis treatment was a decision made by the patient, after trialing medical cannabis, to either continue medical cannabis along with COT at a reduced daily MME, or to revert back to their previous COT regimen.

Setting: This study was performed at the Allegheny Health Network Institute for Pain Medicine in Pittsburgh, Pennsylvania. The state of Pennsylvania legalized medical cannabis in April of 2016, and it became available to patients in February of 2018 through medical dispensaries.

Methods: One hundred and fifteen patients met the inclusion criteria, with the majority of those excluded due to not being treated with COT. Of the 115 who chose to undergo a medical cannabis trial in addition to their COT, 75 chose to remain certified for medical cannabis as they had significant pain relief and subsequently weaned down on opioids. Additionally, of the 115 choosing to undergo a medical cannabis trial, 30 chose to be decertified due to ineffectiveness or side effects, and those were placed back on their COT regimen. The other 10 were not included for other denoted reasons. Compliance was monitored through urine drug screens (UDS).

Results: There was a 67.1% average decrease in daily MME/patient from 49.9 to 16.4 MME at the first follow-up. There was a 73.3% decrease in MME at second follow-up from 49.9 to 13.3 MME with an ANOVA analysis denoting a significant difference of P < 0.0001.

Limitations: The period of follow-up presented at this point includes their first 6 months of treatment with medical cannabis and COT concomitantly.

Conclusions: Presenting medical cannabis to chronic pain patients on COT should be done in the context of a patient choice between medical cannabis WITH decrement of COT or continued current dose of COT in order to maximize effectiveness in opioid reduction as well as to limit polypharmacy concerns regarding medical cannabis. Allowing for a temporary short-term period where patients may trial medical cannabis, while concomitantly gradually weaning their COT, is also essential in determining medical cannabis’ individual effectiveness for that patient’s specific type of chronic pain, which should serve to maximize long-term opioid reduction results and hence decrease opioid-related overdose deaths.”

https://pubmed.ncbi.nlm.nih.gov/35051158/

https://www.painphysicianjournal.com/linkout?issn=&vol=25&page=E113