Medicinal cannabis for Australian patients with chronic refractory pain including arthritis

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“Objectives: To examine the tolerability and effectiveness of medicinal cannabis prescribed to patients for chronic, refractory pain, with a subset analysis on arthritis.

Methods: This was an interim analysis of the CA Clinics Observational Study investigating self-reported adverse events (AEs) and changes in health-related quality of life (HRQoL) outcomes over time after commencing medicinal cannabis. Patients were prescribed medicinal cannabis by a medical practitioner, containing various ratios of Δ9-tetrahydrocannabinol (THC) and/or cannabidiol (CBD).

Results: The overall chronic pain cohort, and specifically the balanced CBD:THC products, were associated with significantly reduced pain intensity scores (p = 0.003, p = 0.025), with 22% of patients reporting a clinically meaningful reduction in pain intensity. Patients in the arthritis subset (n = 199) reported significantly reduced pain intensity scores (p = 0.005) overall, and specifically for those taking CBD-only (p = 0.018) and balanced products (p = 0.005). Other HRQoL outcomes, including pain interference and pain impact scores were significantly improved depending on the CBD:THC ratio. Products that contained a balanced ratio of CBD:THC were associated with improvements in the most number of PROMIS-29 domains. Approximately half (n = 364; 51%) of the chronic pain cohort experienced at least one AE, the most common being dry mouth (24%), somnolence (19%) or fatigue (12%). These findings were similar in the arthritis subset.

Discussion: Medicinal cannabis was observed to improve pain intensity scores and HRQoL outcomes in patients with chronic, refractory pain, providing real-world insights into medicinal cannabis’ therapeutic potential.”

https://pubmed.ncbi.nlm.nih.gov/37057257/

https://journals.sagepub.com/doi/10.1177/20494637221147115

Cannabidiol Treatment Shows Therapeutic Efficacy in a Rodent Model of Social Transfer of Pain in Pair-Housed Male Mice

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“Introduction: Prosocial behavior refers to sharing emotions and sensations such as pain. Accumulated data indicate that cannabidiol (CBD), a nonpsychotomimetic component of the Cannabis sativa plant, attenuates hyperalgesia, anxiety, and anhedonic-like behavior. Nevertheless, the role of CBD in the social transfer of pain has never been evaluated. In this study, we investigated the effects of acute systemic administration of CBD in mice that cohabited with a conspecific animal suffering from chronic constriction injury. Furthermore, we assessed whether repeated CBD treatment decreases hypernociception, anxiety-like behavior, and anhedonic-like responses in mice undergoing chronic constriction injury and whether this attenuation would be socially transferred to the partner. 

Materials and Methods: Male Swiss mice were Housed in pairs for 28 days. On the 14th day of living together, animals were then divided into two groups: cagemate nerve constriction (CNC), in which one animal of each partner was subjected to sciatic nerve constriction; and cagemate sham (CS), subjected to the same surgical procedure but without suffering nerve constriction. In Experiments 1, 2, and 3 on day 28 of living together, the cagemates (CNC and CS) animals received a single systemic injection (intraperitoneally) of vehicle or CBD (0.3, 1, 10, or 30 mg/kg). After 30 min, the cagemates were subjected to the elevated plusmaze followed by exposure to the writhing and sucrose splash tests. For chronic treatment (Exp. 4), sham and chronic constriction injury animals received a repeated systemic injection (subcutaneous) of vehicle or CBD (10 mg/kg) for 14 days after the sciatic nerve constriction procedure. On days 28 and 29 sham and chronic constriction injury animals and their cagemates were behaviorally tested. 

Results and Conclusion: Acute CBD administration attenuated anxiety-like behavior, pain hypersensitivity, and anhedonic-like behavior in cagemates that cohabited with a pair in chronic pain. In addition, repeated CBD treatment reversed the anxiety-like behavior induced by chronic pain and enhanced the mechanical withdrawal thresholds in Von Frey filaments and the grooming time in the sucrose splash test. Moreover, repeated CBD treatment effects were socially transferred to the chronic constriction injury cagemates.”

https://pubmed.ncbi.nlm.nih.gov/37074109/

https://www.liebertpub.com/doi/10.1089/can.2022.0300

Cannabidiol reduces LPS-induced nociception via endocannabinoid system activation

“Bacterial infections are often accompanied by fever and generalized muscle pain. However, the treatment of pain with an infectious etiology has been overlooked. Thus, we investigated the impact of cannabidiol (CBD) in bacterial lipopolysaccharide (LPS)-induced nociception.

Male Swiss mice received intrathecal (i.t.) LPS injection, and the nociceptive threshold was measured by the von Frey filaments test. Spinal involvement of the cannabinoid CB2 receptor, toll-like receptor 4 (TLR4), microglia and astrocytes were evaluated by i.t. administration of their respectively antagonists or inhibitors. Western blot, immunofluorescence, ELISA and liquid chromatography-mass spectrometry were used to assess Cannabinoid CB2 receptors and TLR4 spinal expression, proinflammatory cytokines and endocannabinoid levels. CBD was administered intraperitoneally at 10 mg/kg.

The pharmacological assay demonstrated TLR4 participation in LPS-induced nociception. In addition, spinal TLR4 expression and proinflammatory cytokine levels were increased in this process.

CBD treatment prevented LPS-induced nociception and TLR4 expression.

AM630 reversed antinociception and reduced CBD-induced endocannabinoids upregulation. Increased spinal expression of the cannabinoid CB2 receptor was also found in animals receiving LPS, which was accompanied by reduced TLR4 expression in CBD-treated mice.

Taken together, our findings indicated that CBD is a potential treatment strategy to control LPS-induced pain by attenuating TLR4 activation via the endocannabinoid system.”

https://pubmed.ncbi.nlm.nih.gov/37076976/

https://onlinelibrary.wiley.com/doi/10.1111/bcpt.13876

Combined non-psychoactive Cannabis components cannabidiol and β-caryophyllene reduce chronic pain via CB1 interaction in a rat spinal cord injury model

Lopiccolo & Chang in PLoS ONE – BU Linguistics

“The most frequently reported use of medical marijuana is for pain relief. However, its psychoactive component Δ9-tetrahydrocannabinol (THC) causes significant side effects. Cannabidiol (CBD) and β-caryophyllene (BCP), two other cannabis constituents, possess more benign side effect profiles and are also reported to reduce neuropathic and inflammatory pain. We evaluated the analgesic potential of CBD and BCP individually and in combination in a rat spinal cord injury (SCI) clip compression chronic pain model. Individually, both phytocannabinoids produced dose-dependent reduction in tactile and cold hypersensitivity in male and female rats with SCI. When co-administered at fixed ratios based on individual A50s, CBD and BCP produced enhanced dose-dependent reduction in allodynic responses with synergistic effects observed for cold hypersensitivity in both sexes and additive effects for tactile hypersensitivity in males. Antinociceptive effects of both individual and combined treatment were generally less robust in females than males. CBD:BCP co-administration also partially reduced morphine-seeking behavior in a conditioned place preference (CPP) test. Minimal cannabinoidergic side effects were observed with high doses of the combination. The antinociceptive effects of the CBD:BCP co-administration were not altered by either CB2 or μ-opioid receptor antagonist pretreatment but, were nearly completely blocked by CB1 antagonist AM251. Since neither CBD or BCP are thought to mediate antinociception via CB1 activity, these findings suggest a novel CB1 interactive mechanism between these two phytocannabinoids in the SCI pain state. Together, these findings suggest that CBD:BCP co-administration may provide a safe and effective treatment option for the management of chronic SCI pain.”

https://pubmed.ncbi.nlm.nih.gov/36913400/

“In conclusion, the current findings indicate that the combination of readily accessible non-psychoactive cannabis components CBD oil and BCP may be particularly effective in reducing neuropathic pain resulting from spinal cord injury. In addition, cannabinoid-like side effects were minimal using this combination. Further, the observed decrease in opioid-seeking behavior suggest that this treatment may be useful as a supplemental therapeutic to reduce opioid needed for effective pain management. Together, these findings are supportive of the beneficial effects of combining cannabis components in the armamentarium for chronic pain management.”

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0282920

The antinociceptive activity and mechanism of action of cannabigerol

Biomedicine & Pharmacotherapy

“Cannabis has been used for centuries to treat pain.

The antinociceptive activity of tetrahydrocannabinol (THC) or cannabidiol (CBD) has been widely studied. However, the antinociceptive effects of other cannabis components, such as cannabichromene (CBC) and cannabigerol (CBG), have rarely been revealed. The antinociceptive mechanism of CBG is not yet clear, so we investigated the antinociceptive effect of CBG on different pain models, and explored the mechanism of action of CBG to exert antinociceptive effects.

In the current study, we compared the antinociceptive effects of CBC, CBD, and CBG on the carrageenan-induced inflammatory pain model in mice, and the results showed that CBG had a better antinociceptive effects through intraplantar administration. On this basis, we further investigated the antinociceptive effect of CBG on CIA-induced arthritis pain model and nerve pain model in mice, and found that CBG also relieved on both types of pain. Then, we explored the antinociceptive mechanism of CBG, which revealed that CBG can activate TRPV1 and desensitize it to block the transmission of pain signals. In addition, CBG can further activate CB2R, but not CB1R, to stimulate the release of β-endorphin, which greatly promotes the antinociceptive effect.

Finally, the safety test results showed that CBG had no irritating effect on the rabbits’ skin, and it did not induce significant biochemical and hematological changes in mice. Transdermal delivery results also indicated that CBG has certain transdermal properties. Overall, this study indicates that CBG is promising for developing a transdermal dosage for pain management.”

https://pubmed.ncbi.nlm.nih.gov/36916438/

“Cannabigerol can exert antinociceptive effects on multiple pain models.”

https://www.sciencedirect.com/science/article/pii/S0753332222015529?via%3Dihub

Comparing the effects of medical cannabis for chronic pain patients with and without co-morbid anxiety: A cohort study

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“Introduction: There is growing evidence on the efficacy of cannabis-based medicinal products (CBMPs) for chronic pain (CP). Due to the interaction between CP and anxiety, and the potential impact of CBMPs on both anxiety and CP, this article aimed to compare the outcomes of CP patients with and without co-morbid anxiety following CBMP treatment.

Methods: Participants were prospectively enrolled and categorized by baseline General Anxiety Disorder-7(GAD-7) scores, into ‘no anxiety'(GAD-7 < 5) and ‘anxiety'(GAD-7 ≥ 5) cohorts. Primary outcomes were changes in Brief Pain Inventory Short-Form, Short-form McGill Pain Questionnaire-2, Pain Visual Analogue Scale, Sleep Quality Scale (SQS), GAD-7 and EQ-5D-5L index values at 1, 3 and 6 months.

Results: 1254 patients (anxiety = 711; no anxiety = 543) met inclusion criteria. Significant improvements in all primary outcomes were observed at all timepoints (p < 0.050), except GAD-7 in the no anxiety group(p > 0.050). The anxiety cohort reported greater improvements in EQ-5D-5L index values, SQS and GAD-7(p < 0.050), but there were no consistent differences in pain outcomes.

Conclusion: A potential association between CBMPs and improvements in pain and health-related quality of life (HRQoL) in CP patients was identified. Those with co-morbid anxiety reported greater improvements in HRQoL.”

https://pubmed.ncbi.nlm.nih.gov/36803620/

“A potential association between initiation of CBMPs and improvements in pain and HRQoL, as well as reductions in opioid consumption and an acceptable AE profile in both cohorts was found, complimenting previous UKMCR studies. Moreover, CP patients with co-morbid anxiety may achieve better HRQoL outcomes and potentially pain outcomes due to CBMPs’ peripheral and central effects.”

https://www.tandfonline.com/doi/full/10.1080/14737175.2023.2181696

Medical Cannabis for Chronic Nonmalignant Pain Management

SpringerLink

“Purpose of review: Cannabis has been used since ancient times for medical and recreational research. This review article will document the validity of how medical cannabis can be utilized for chronic nonmalignant pain management.

Recent findings: Current cannabis research has shown that medical cannabis is indicated for symptom management for many conditions not limited to cancer, chronic pain, headaches, migraines, and psychological disorders (anxiety and post-traumatic stress disorder). Δ9-Tetrahydrocannabinol (THC) and cannabidiol (CBD) are active ingredients in cannabis that modulate a patient’s symptoms. These compounds work to decrease nociception and symptom frequency via the endocannabinoid system. Research regarding pain management is limited within the USA as the Drug Enforcement Agency (DEA) classifies it as a schedule one drug. Few studies have found a limited relationship between chronic pain and medical cannabis use. A total of 77 articles were selected after a thorough screening process using PubMed and Google Scholar. This paper demonstrates that medical cannabis use provides adequate pain management. Patients suffering from chronic nonmalignant pain may benefit from medical cannabis due to its convenience and efficacy.”

https://pubmed.ncbi.nlm.nih.gov/36897501/

“Patients often seek medical consultations most commonly because of having intolerable chronic pain. Medications such as NSAIDs or opioids are being used to relieve such pain. However, long-term use of these medications can also cause adverse effects on health. Several studies have been done regarding cannabis as an alternative for chronic pain. Some patients were reported to get relief from cannabis consumption through various routes, and the use of it has been legalized, too, in some states in the USA and countries like Germany. Italy, the Netherlands, UK, Australia, Uruguay, Brazil, Colombia, Chile, Thailand, and Jamaica. Compared with opioids, studies show that cannabis use has lesser adverse effects, and it could even lessen opioid dependence.”

https://link.springer.com/article/10.1007/s11916-023-01101-w

Patient Reported Outcomes Using Medical Cannabis for Managing Pain in Charcot-Marie-Tooth Disease

SAGE Journals Home

“Objective: Chronic pain is a major problem for patients with Charcot-Marie-Tooth (CMT) disease. This exploratory study examined patient reported efficacy of medical cannabis for pain management in this population. 

Methods: Participants (N = 56; 71.4% female; Age = 48.9, SD = 14.6; 48.5% CMT1) were recruited though the Hereditary Neuropathy Foundation. The online survey contained 52 multiple choice questions about demographics, medical cannabis use, symptomology, efficacy, and adverse effects. 

Results: Nearly all (90.9%) of respondents reported experiencing pain, including all (100%) females and 72.7% of males (chi-square P < .05) with 91.7% of respondents indicating cannabis provided at least 50% pain relief. The most frequent response was an 80% reduction in pain. Moreover, 80.0% of respondents reported using less opiates, 69% noted using less sleep medication, and 50.0% reported using less anxiety/antidepressant medications. Negative side effects were noted by 23.5% of respondents. However, almost all (91.7%) of that subgroup did not have plans to stop consuming cannabis. One-third (33.9%) possessed a medical cannabis certificate. Patient perceptions of their physicians’ attitudes regarding patient medical cannabis use greatly impacted whether respondents informed their providers of their usage. 

Conclusion: The vast majority of patients with CMT reported that cannabis was effective to manage pain symptoms. These data support the need for prospective, randomized, controlled trials using standardized dosing protocols to further delineate and optimize the potential use of cannabis to treat pain related to CMT.”

https://pubmed.ncbi.nlm.nih.gov/36793224/

https://journals.sagepub.com/doi/10.1177/10499091231158388

Changes in Prescribed Opioid Dosages Among Patients Receiving Medical Cannabis for Chronic Pain, New York State, 2017-2019

JAMA editors name the journal's best articles of the decade | American  Medical Association

“Importance: Patients with chronic pain often receive long-term opioid therapy (LOT), which places them at risk of opioid use disorder and overdose. This presents the need for alternative or companion treatments; however, few studies on the association of medical cannabis (MC) with reducing opioid dosages exist.

Objective: To assess changes in opioid dosages among patients receiving MC for longer duration compared with shorter duration.

Design, setting, and participants: This cohort study of New York State Prescription Monitoring Program data from 2017 to 2019 included patients receiving MC for chronic pain while also receiving opioid treatment. Of these, patients receiving LOT prior to receiving MC were selected. Individuals were studied for 8 months after starting MC. Data were analyzed from November 2021 to February 2022.

Exposures: Selected patients were divided into 2 groups based on the duration of receiving MC: the nonexposure group received MC for 30 days or fewer, and the exposure group received MC for more than 30 days.

Main outcomes and measures: The main outcome was opioid dosage, measured by mean daily morphine milligram equivalent (MME). Analyses were conducted for 3 strata by opioid dosage prior to receiving MC: MME less than 50, MME of 50 to less than 90, and MME of 90 or greater.

Results: A total of 8165 patients were included, with 4041 (median [IQR] age, 57 [47-65] years; 2376 [58.8%] female) in the exposure group and 4124 (median [IQR] age, 54 (44-62) years; 2370 [57.5%] female) in the nonexposure group. Median (IQR) baseline MMEs for the exposure vs nonexposure groups were 30.0 (20.0-40.0) vs 30.0 (20.0-40.0) in the lowest stratum, 60.0 (60.0-70.0) vs 60.0 (60.0-90.0) in the middle stratum, and 150.0 (100.0-216.2) vs 135.0 (100.0-218.0) in the highest stratum. During follow-up, significantly greater reductions in opioid dosage were observed among the exposure group. A dose-response association of patients’ opioid dosage at baseline was observed with the differences in the monthly MME reductions between exposure and nonexposure groups, with a difference of -1.52 (95% CI, -1.67 to -1.37) MME for the lowest stratum, -3.24 (95% CI, -3.61 to -2.87) MME for the middle stratum, and -9.33 (95% CI, -9.89 to -8.77) MME for the highest stratum. The daily MME for the last month of the follow-up period among patients receiving longer MC was reduced by 48% in the lowest stratum, 47% in the middle stratum, and 51% in the highest stratum compared with the baseline dosages. Among individuals in the nonexposure group, daily MME was reduced by only 4% in the lowest stratum, 9% in the middle stratum, and 14% in the highest stratum.

Conclusions and relevance: In this cohort study of patients receiving LOT, receiving MC for a longer duration was associated with reductions in opioid dosages, which may lower their risk of opioid-related morbidity and mortality.”

https://pubmed.ncbi.nlm.nih.gov/36716026/

“This cohort study found that receiving MC for longer was associated with opioid dosage reductions. The reductions were larger among individuals who were prescribed higher dosages of opioids at baseline. These findings contribute robust evidence for clinicians regarding the potential benefits of MC in reducing the opioid burden for patients receiving LOT and possibly reduce their risk for overdose.”

https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2800813

“State DOH: Medical cannabis may reduce opioid burden in managing chronic pain”

https://www.troyrecord.com/2023/02/02/state-doh-releases-study-on-role-of-medical-cannabis-for-chronic-pain-reduction/

Inhaled Δ9-tetrahydrocannabinol does not enhance oxycodone-induced respiratory depression: randomised controlled trial in healthy volunteers

British Journal of Anaesthesia | The Royal College of Anaesthetists

“Background: In humans, the effect of cannabis on ventilatory control is poorly studied, and consequently, the effect of Δ9-tetrahydrocannabinol (THC) remains unknown, particularly when THC is combined with an opioid. We studied the effect of THC on breathing without and with oxycodone pretreatment. We hypothesised that THC causes respiratory depression, which is amplified when THC and oxycodone are combined.

Methods: In this randomised controlled crossover trial, healthy volunteers were administered inhaled Bedrocan® 100 mg (Bedrocan International B.V., Veendam, The Netherlands), a pharmaceutical-grade high-THC cannabis variant (21.8% THC; 0.1% cannabidiol), after placebo or oral oxycodone 20 mg pretreatment; THC was inhaled 1.5 and 4.5 h after placebo or oxycodone intake. The primary endpoint was isohypercapnic ventilation at an end-tidal Pco2 of 55 mm Hg or 7.3 kPa (VE55), measured at 1-h intervals for 7 h after placebo/oxycodone intake.

Results: In 18 volunteers (age 22 yr [3]; 9 [50%] female), oxycodone produced a 30% decrease in VE55, whereas placebo was without effect on VE55. The first cannabis inhalation resulted in VE55 changing from 20.3 (3.1) to 23.8 (2.4) L min-1 (P=0.06) after placebo, and from 11.8 (2.8) to 13.0 (3.9) L min-1 (P=0.83) after oxycodone. The second cannabis inhalation also had no effect on VE55, but slightly increased sedation.

Conclusions: In humans, THC has no effect on ventilatory control after placebo or oxycodone pretreatment.”

https://pubmed.ncbi.nlm.nih.gov/36725378/

“In pain management, the use of THC or its combination with an opioid can be advantageous, as the combination has an opioid-sparing effect.

However, this is only of advantage provided the combination of these two drug classes does not exacerbate opioid-induced respiratory depression.

In this study, we examined the effect of inhaled medicinal-grade cannabis, containing a high THC dose, on ventilatory control in healthy human volunteers with placebo or oxycodone pretreatment. 

THC has no effect on ventilatory control after placebo or oxycodone pretreatment.

In summary, in human volunteers, THC has no significant effect on ventilatory control after placebo or oxycodone pretreatment.”

https://www.bjanaesthesia.org/article/S0007-0912(22)00743-7/fulltext