Cannabis and Pain: A Clinical Review

Study of the relationship between psychoactive substance use and pain in cancer patients and cancer survivors: A French nationwide cross-sectional study

Pain is a prevalent symptom among cancer patients and survivors. Psychoactive substance use (PSU) is associated with both the presence and severity of pain. However, little is known about this association in the context of cancer. The primary objective was to compare the prevalence of PSU and its relationship with pain during and after cancer. PSU was defined as the use of nonmedication substances (alcohol, tobacco, e-cigarettes, cannabidiol, and cannabis), with frequency categorized as at least yearly, monthly, weekly, or daily. Secondary objectives aimed to explore the relationships between PSU and pain characteristics, health-related quality of life, anxiety, depression, deprivation, and individual characteristics. Among the 1041 individuals included, pain prevalence was 44.7% (95% confidence interval [CI] 41.6%-47.8%). The overall prevalence of PSU at least monthly was 67.0% (95% CI 64.0%-69.8%). The proportions of chronic and neuropathic pains were higher for at least monthly use of cannabidiol compared to nonuse (70.0% vs. 39.3% and 55.7% vs. 28.1%, p < .001). In multivariate analysis, the monthly uses of tobacco and cannabidiol were higher in painful individuals than in nonpainful ones (odds ratio: 2.85 [95% CI 1.22-6.64] and 3.76 [95% CI 1.13-12.44], p < .05). From the point of view of the patient care, the study underscores the need for physicians to prioritize smoking cessation and pay attention to the use of cannabidiol during and after cancer.

Cannabidiol (CBD) and hemp oil use in veterans using a VA Pain Clinic: a cross-sectional survey study

BACKGROUND

Many United States veterans utilize prescription opioids to treat chronic pain symptoms and are subsequently at risk for opioid and alcohol misuse. As more states legalized the use of cannabis for medical use, increasing numbers of people are using cannabis pharmacotherapy for pain. The veterans Health Administration (VHA) Directive 1315, July 28, 2023 prohibits any medical staff on recommending, making referral to, and complete forms for a state approved program. Also, a veterans medical center does not provide marijuana to veterans. State laws do not change the status of CBD under federal law. CBD is illegal in the federal system.

OBJECTIVES

Our aim was to investigate the prevalence of cannabidiol product usage in Veterans and the association with changes in self-reported pain.

METHODS

We conducted a cross-sectional descriptive survey offering questionnaires to patients greater than 18 years of age receiving care at the Fargo Veteran Health Administration medical center Pain Clinic (2101 Elm St N, Fargo ND, 58102).

RESULTS

A total of 218 veterans participated of which 81.2% were male and 52.3% were in the age range of 60-80 years. Twenty-one participants reported cannabidiol usage (9.6%), with 52.4% using to treat pain symptoms. Average pain scores pre-usage of 6.37 were reduced to 4.05 post-usage indicating a statistically significant reduction in pain (p < 0.001).

CONCLUSION

Our study broadened the baseline knowledge of cannabidiol use in the Veteran population. Limitations include results being self-reported and the inability to verify cannabinoid constituents.

Pierre M, Belle-Isle L, Gagnon M, Bevan S, Sanchez T, Arlt S, Monahan-Ellison M, O'Hara J, Boivin M, Costiniuk C. Clinical Practice Guidelines for Cannabis and Cannabinoid-Based Medicines in the Management of Chronic Pain and Co-Occurring Conditions

Background: One in five individuals live with chronic pain globally, which often co-occurs with sleep problems, anxiety, depression, and substance use disorders. Although these conditions are commonly managed with cannabinoid-based medicines (CBM), health care providers report lack of information on the risks, benefits, and appropriate use of CBM for therapeutic purposes. Aims: We present these clinical practice guidelines to help clinicians and patients navigate appropriate CBM use in the management of chronic pain and co-occurring conditions. Materials and Methods: We conducted a systematic review of studies investigating the use of CBM for the treatment of chronic pain. Articles were dually reviewed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Clinical recommendations were developed based on available evidence from the review. Values and preferences and practical tips have also been provided to support clinical application. The GRADE system was used to rate the strength of recommendations and quality of evidence. Results: From our literature search, 70 articles met inclusion criteria and were utilized in guideline development, including 19 systematic reviews and 51 original research studies. Research typically demonstrates moderate benefit of CBM in chronic pain management. There is also evidence for efficacy of CBM in the management of comorbidities, including sleep problems, anxiety, appetite suppression, and for managing symptoms in some chronic conditions associated with pain including HIV, multiple sclerosis, fibromyalgia, and arthritis. Conclusions: All patients considering CBM should be educated on risks and adverse events. Patients and clinicians should work collaboratively to identify appropriate dosing, titration, and administration routes for each individual. Systematic Review Registration: PROSPERO no. 135886.

Pleiotropy and genetically inferred causality linking multisite chronic pain to substance use disorders

Individuals suffering from chronic pain develop substance use disorders (SUDs) more often than others. Understanding the shared genetic influences underlying the comorbidity between chronic pain and SUDs will lead to a greater understanding of their biology. Genome-wide association statistics were obtained from the UK Biobank for multisite chronic pain (MCP, Neffective = 387,649) and from the Million Veteran Program and the Psychiatric Genomics Consortium meta-analyses for alcohol use disorder (AUD, Neffective = 296,974), cannabis use disorder (CanUD, Neffective = 161,053), opioid use disorder (OUD, Neffective = 57,120), and problematic tobacco use (PTU, Neffective = 270,120). SNP-based heritability was estimated for each of the traits and genetic correlation (rg) analyses were performed to assess MCP-SUD pleiotropy. Bidirectional Mendelian Randomization analyses evaluated possible causal relationships. Finally, to identify and characterize individual loci, we performed a genome-wide pleiotropy analysis and a brain-wide analysis using imaging phenotypes available from the UK Biobank. MCP was positively genetically correlated with AUD (rg = 0.26, p = 7.55 × 10-18), CanUD (rg = 0.37, p = 8.21 × 10-37), OUD (rg = 0.20, p = 1.50 × 10-3), and PTU (rg = 0.29, p = 8.53 × 10-12). Although the MR analyses supported bi-directional relationships, MCP had larger effects on AUD (pain-exposure: beta = 0.18, p = 8.21 × 10-4; pain-outcome: beta = 0.07, p = 0.018), CanUD (pain-exposure: beta = 0.58, p = 2.70 × 10-6; pain-outcome: beta = 0.05, p = 0.014) and PTU (pain-exposure: beta = 0.43, p = 4.16 × 10-8; pain-outcome: beta = 0.09, p = 3.05 × 10-6) than the reverse. The genome-wide analysis identified two SNPs pleiotropic between MCP and all SUD investigated: IHO1 rs7652746 (ppleiotropy = 2.69 × 10-8), and CADM2 rs1248857 (ppleiotropy = 1.98 × 10-5). In the brain-wide analysis, rs7652746 was associated with multiple cerebellum and amygdala imaging phenotypes. When analyzing MCP pleiotropy with each SUD separately, we found 25, 22, and 4 pleiotropic variants for AUD, CanUD, and OUD, respectively. To our knowledge, this is the first large-scale study to provide evidence of potential causal relationships and shared genetic mechanisms underlying MCP-SUD comorbidity.

Bibliometric Analysis of Cannabis sativa Research: Trends, Challenges, and Future Directions

Introduction: The use of medical Cannabis remains unregulated in several countries due to the scarcity of clinical studies with high scientific evidence that establish safety and efficacy of Cannabis products. This study aimed to comprehensively analyze how knowledge has been created in this field, as well as perform a bibliographic mapping to identify knowledge gaps, and investigate key authors and journals that have significantly contributed to advancing our understanding of Cannabis. Method: The study protocol was registered in the International Prospective Register of Systematic Review (CRD42020223084). A systematic search was conducted in the Cochrane Central Register of Controlled Trials, Lilacs, Google Scholar, PubMed, SciELO, Scopus, and Web of Science databases. The bibliographic analysis and mapping were registered using the VOSviewer, Sci2tool, CiteSpace, and PoP software. Results: The systematic search identified 27,597 records, with 17,020 duplicates, resulting in a total of 10,577 articles included. The authors who published the most were Marilyn Ann Huestis (n=108) and Sagnik Bhattacharyya (n=71), while Elisaldo A. Carlini and Raphael Mechoulam published 8 and 22 articles, respectively. The journals Drug and Alcohol Dependence (n=297), Psychopharmacology (n=159) and Addictive Behaviors (n=150) were the ones that published the most on Cannabis. The journals suggest that the articles are correlated with the adverse and toxicological effects of recreational Cannabis use; however, most articles focus on medical Cannabis. The peak of publications was in 2021 (n=1,481). The countries that published the most were the United States (n=9,735), while Brazil occupied the 11th position (n=422). Most publications were carried out in "Pharmacology and Pharmacy" (11.31%), followed by "Psychiatry" (7.66%) and "Medicine" (5.80%). The areas of "Neurosciences" (1.59%), "Biochemistry," "Genetics," and "Molecular Biology" (0.79%) were little explored. Conclusion: This study captured the characteristics of publications about Cannabis and clinical studies in the scientific literature, yielding >10,000 articles, representing a large literature review, to date. Therefore, the most productive countries included the United States, the United Kingdom, and Canada, while the most productive authors were Marilyn Ann Huestis and Sagnik Bhattacharyya, with a peak of publications in 2021. Finally, the most chosen journals were Drug and Alcohol Dependence and Psychopharmacology.

Cannabis Use Following Total Joint Arthroplasty is Associated With Increased Risks? A Meta-Analysis

BACKGROUND

With the increased legalization of cannabis, a new unknown emerges for orthopaedic surgeons and their patients. This systematic review aimed to (1) evaluate complications of cannabis use; (2) determine the effects of cannabis on pain and opioid consumption; and (3) evaluate healthcare utilizations associated with cannabis use among patients undergoing total joint arthroplasty (TJA).

METHODS

A systematic review was performed. A search of the literature was performed in 5 databases. We included studies between January 2012 and July 2022 reporting cannabis use and complications, pain management, opioid consumption, length of stay, costs, or functional outcomes following TJA. A meta-analysis of odds ratios (ORs) and continuous variables was performed. A total of 19 articles were included in our final analysis.

RESULTS

Cannabis use was associated with higher odds for deep vein thrombosis (DVT) (OR: 1.46, 95% Confidence Interval [CI]: 1.13 to 1.89) and revisions (OR: 1.47 [95% CI: 1.41 to 1.53]) in total knee arthroplasty (TKA). Cannabis use was associated with similar odds for DVT in total hip arthroplasty (THA) (OR: 1.30 [95% CI: 0.79 to 2.13]), pulmonary embolus in both TKA (OR: 1.29 [95% CI: 0.95 to 1.77]), THA (OR: 0.55 [95% CI: 0.09 to 3.28]), and cardiovascular complications in TKA (OR: 1.97 [95% Cl: 0.93 to 4.14]). Cannabis use did not alter pain scores, opioid consumption, or cost of care in THA (estimate: $2,550.51 [95% CI: $356.58 to $5,457.62]) but was associated with higher costs in TKA (estimate: $3,552.46 [95% CI: $1,729.71 to $5,375.22]). There was no difference in lengths of stay or functional outcomes; however, there may be a potentially increased risk for prosthetic complications, pneumonia, and cerebrovascular accidents among cannabis users.

CONCLUSION

Cannabis use may be associated with an increased risk of DVTs, revisions, pneumonia, cerebrovascular accidents, and cardiac complications after TJA. Higher-level studies are needed to ascertain the impact of cannabis use for patients undergoing TJA.

Can cannabidiol have an analgesic effect?

BACKGROUND

Cannabis, more commonly known as marijuana or hemp, has been used for centuries to treat various conditions. Cannabis contains two main components cannabidiol (CBD) and tetrahydrocannabinol (THC). CBD, unlike THC, is devoid of psychoactive effects and is well tolerated by the human body but has no direct effect on the receptors of the endocannabid system, despite the lack of action on the receptors of the endocannabid system.

OBJECTIVES AND METHODS

We have prepared a literature review based on the latest available literature regarding the analgesic effects of CBD. CBD has a wide range of effects on the human body. In this study, we will present the potential mechanisms responsible for the analgesic effect of CBD. To the best of our knowledge, this is the first review to explore the analgesic mechanisms of CBD.

RESULTS AND CONCLUSION

The analgesic effect of CBD is complex and still being researched. CBD models the perception of pain by acting on G protein-coupled receptors. Another group of receptors that CBD acts on are serotonergic receptors. The effect of CBD on an enzyme of potential importance in the production of inflammatory factors such as cyclooxygenases and lipoxygenases has also been confirmed. The presented potential mechanisms of CBD's analgesic effect are currently being extensively studied.

Pharmacokinetics and pharmacodynamics of cannabis-based medicine in a patient population included in a randomized, placebo-controlled, clinical trial

Information on the pharmacokinetics (PK) and pharmacodynamics (PD) of orally administered cannabis-based medicine (CBM) in capsule formulation in patient populations is sparse. In this exploratory study, we aimed to evaluate the PK and PD in a probable steady state of CBM in neuropathic pain and spasticity in a population of patients with multiple sclerosis (MS). Of 134 patients participating in a randomized, double-blinded, placebo-controlled, trial, 23 patients with MS (17 female) mean age 52 years (range 21-67) were enrolled in this substudy. They received oral capsules containing Δ9 -tetrahydrocannabinol (THC, n = 4), cannabidiol (CBD, n = 6), a combination (THC&CBD, n = 4), or placebo (n = 9). Maximum doses were 22.5 mg (THC) and 45 mg (CBD) a day divided into three administrations. PD parameters were evaluated for pain and spasticity. Blood samples were analyzed using an ultra-high-performance liquid chromatography-tandem mass spectrometer after protein precipitation and phospholipid removal. PK parameters were estimated using computerized modeling. The variation in daily dose and PK between individuals was considerable in a steady state, yet comparable with previous reports from healthy controls. Based on a simulation of the best model, the estimated PK parameters (mean) for THC (5 mg) were Cmax 1.21 ng/mL, Tmax 2.68 h, and half-life 2.75 h, and for CBD (10 mg) were Cmax 2.67 ng/mL, Tmax 0.10 h, and half-life 4.95 h, respectively. No effect was found on the PD parameters, but the placebo response was considerable. More immediate adverse events were registered in the active treatment groups compared with the placebo group.

Cannabis and Cannabinoids in the Perioperative Period

Cannabis use is increasingly common, and with a growing number of jurisdictions implementing legalization frameworks, it is likely that providers will encounter more patients who use cannabis. Therefore, it is important for providers to understand the implications of cannabis use and practical considerations for the perioperative period. Cannabis affects multiple organ systems and may influence intraoperative anesthesia, as well as postoperative pain management. The effects of cannabis and key anesthetic considerations are reviewed here.

Physician Perceptions of Cannabidiol (CBD) and Cannabis in Sports Medicine and Performance

Objectives

There is growing evidence regarding cannabinoid use in sports medicine and performance, especially cannabidiol (CBD). This study aims to determine if sports medicine physicians are recommending cannabinoids for therapeutic purposes, as well as analyze perceptions of cannabinoids within sports medicine and performance.

Methods

Physician members of the American Medical Society for Sports Medicine (AMSSM) completed an anonymous survey on demographics, CBD and Cannabis recommendations, as well as attitudes toward cannabinoid products within sports medicine. Factors associated with CBD and cannabis recommendations as well as perceptual differences were found using multivariate regression modelling.

Results

Responses from 333 physicians were recorded. The following groups were less likely to agree with allowing cannabis for recreational purposes: female gender (coeff. = 0.79 (0.33-1.25), p=0.001), increasing age (coeff. = 0.04 (0.02, 0.07), p  <  0.001), and rural respondents (compared to baseline urban, coeff. = 1.16 (0.36, 1.95), p=0.004). Similarly, these three factors were associated with a higher likelihood of disagreeing with WADA removing cannabis from the prohibited substance list and with the NCAA allowing CBD use by collegiate athletes (p ≤ 0.045). CBD was less likely to be recommended by pediatricians, rural physicians, and academic physicians (p ≤ 0.030). Male physicians and younger physicians were less likely to identify cannabis as performance-enhancing (p ≤ 0.042).

Conclusions

Sports medicine physicians have varying views on cannabinoids. While sports medicine physicians generally have favorable attitudes toward CBD and cannabis, these perceptions appear to be significantly affected by age, practice type, and gender.

Perioperative Management of Patients with Craniomaxillofacial Trauma

Successful surgical management of patients with facial fractures requires a detailed preoperative evaluation and postoperative management that differs from elective surgical patients. This review presents evidence-based recommendations from the surgical and anesthesiology literature that address many of the clinical questions that arise during the perioperative management of this group of patients. Surgeons and anesthesiologists must work together at numerous points and make joint decisions, especially where airway and pain management challenges may arise. The multidisciplinary nature of the decision-making process is emphasized.

Past Cannabis Use, Health-Related Worry, and Beliefs About Perceived Benefits of Cannabis Among American Indians/Alaska Natives

BACKGROUND

Most adults report beliefs that cannabis has at least one benefit (e.g., stress relief, chronic pain management); however, the benefits are not well established. Beliefs about cannabis benefits are associated with the initiation of use, whereas beliefs about the risks of cannabis are protective factors against its use. Little is known about how health-related beliefs impact cannabis use among American Indians/Alaska Natives (AIAN).

PURPOSE

This exploratory study examined beliefs about perceived benefits (i.e., stress relief, pain management) of cannabis, how beliefs vary as a function of use, and associations between health worry and benefits of cannabis among AIAN adults.

METHODS

Participants (n = 182) were on average 41.4 (SD = 16.3) years old, 63.9% female, and identified as AIAN. Participants were asked questions about general demographics, health-related worry and perceptions, and cannabis use. Linear regressions were conducted to examine associations.

RESULTS

Those who used cannabis in the past year were more likely to agree that cannabis relieves stress and less likely to believe that those who use cannabis should be very worried about their health. Participants who agreed that those who use cannabis should be worried about their health were less likely to report beliefs that cannabis relieves stress or helps with chronic pain.

CONCLUSIONS

Our study confirms the role of health-related perceptions and worry about cannabis products with cannabis use among this population that may be at risk for higher cannabis use. Findings may have implications for cannabis policy at the tribal, state, and federal levels and the need for the development of targeted communications about the true health risks of cannabis.

Pharmacokinetic and pharmacodynamic herb-drug interactions-part I. Herbal medicines of the central nervous system

Unlike conventional drug substances, herbal medicines are composed of a complex of biologically active compounds. Therefore, the potential occurrence of herb-drug interactions is even more probable than for drug-drug interactions. Interactions can occur on both the pharmacokinetic and pharmacodynamic level. Herbal medicines may affect the resulting efficacy of the concomitantly used (synthetic) drugs, mainly on the pharmacokinetic level, by changing their absorption, distribution, metabolism, and excretion. Studies on the pharmacodynamic interactions of herbal medicines and conventional drugs are still very limited. This interaction level is related to the mechanism of action of different plant constituents. Herb-drug interactions can cause changes in drug levels and activities and lead to therapeutic failure and/or side effects (sometimes toxicities, even fatal). This review aims to provide a summary of recent information on the potential drug interactions involving commonly used herbal medicines that affect the central nervous system (Camellia, Valeriana, Ginkgo, Hypericum, Humulus, Cannabis) and conventional drugs. The survey databases were used to identify primary scientific publications, case reports, and secondary databases on interactions were used later on as well. Search keywords were based on plant names (botanical genera), officinal herbal drugs, herbal drug preparations, herbal drug extracts.

Daily cannabis use may cause cannabis-induced hyperalgesia

BACKGROUND AND OBJECTIVES

Public opinion about cannabis as a medical treatment is generally favorable. As many as 35% of primary care patients report medical use of cannabis, most commonly for pain treatment. We designed a way to test whether cannabis helps chronic pain.

METHODS

A retrospective cohort study was conducted to explore whether daily long-term cannabis use was associated with increased pain sensitivity using the cold pressor test (CPT) to measure pain tolerance. Patients who used cannabis every day were compared to patients who inhaled tobacco and control patients who never used tobacco or cannabis. The effect of cannabis use on CPT was assessed using a generalized linear model.

RESULTS

Patients using cannabis daily had a median CPT of 46 s, similar to those who did not use cannabis but who inhaled tobacco (median CPT 45 s). Patients who used both cannabis and tobacco had the lowest CPT (median 26 s). The control group had a median CPT of 105 s. Cannabis use was associated with a significantly decreased pain tolerance (χ²(1)  = 8.0, p = .004). The effect of tobacco on CPT was only marginally significant (χ²(1)  = 3.8, p = .052).

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

This suggests a phenomenon similar to opioid-induced hyperalgesia; a drug that reduces pain short term, induces pain long term-opponent process. Daily cannabis use may make chronic pain worse over time by reducing pain tolerance. In terms of risk/benefit, daily cannabis users risk addiction without any long-term benefit for chronic pain.

The Place of Cannabinoids in the Treatment of Gynecological Pain

Cannabis sativa (L), a plant with an extensive history of medicinal usage across numerous cultures, has received increased attention over recent years for its therapeutic potential for gynecological disorders such as endometriosis, chronic pelvic pain, and primary dysmenorrhea, due at least in part to shortcomings with current management options. Despite this growing interest, cannabis inhabits an unusual position in the modern medical pharmacopoeia, being a legal medicine, legal recreational drug, and an illicit drug, depending on jurisdiction. To date, the majority of studies investigating cannabis use have found that most people are using illicit cannabis, with numerous obstacles to medical cannabis adoption having been identified, including outdated drug-driving laws, workplace drug testing policies, the cost of quality-assured medical cannabis products, a lack of cannabis education for healthcare professionals, and significant and persistent stigma. Although currently lacking robust clinical trial data, a growing evidence base of retrospective data, cohort studies, and surveys does support potential use in gynecological pain conditions, with most evidence focusing on endometriosis. Cannabis consumers report substantial reductions in pelvic pain, as well as common comorbid symptoms such as gastrointestinal disturbances, mood disorders such as anxiety and depression, and poor sleep. Substitution effects were reported, with >50% reduction or cessation in opioid and/or non-opioid analgesics being the most common. However, a substantial minority report not disclosing cannabis consumption to their health professional. Therefore, while such deprescribing trends are potentially beneficial, the importance of medical supervision during this process is paramount given the possibility for withdrawal symptoms.

Medicinal use of cannabis: A qualitative study of the perspectives of doctors and pharmacists from six African countries

We conducted a qualitative study to examine the enablers and barriers influencing the implementation of medical cannabis from the perspectives of practicing doctors and pharmacists within the African context. Interviews were conducted to investigate medical professionals' perceptions and concerns regarding medicinal cannabis. Three major themes were identified: beliefs about consequences, optimism, and environmental resources and context. Depending on the context of use, medical professionals described cannabis as potentially useful as an adjunct medicine and yet problematic owing to knowledge and social barriers, particularly religion. Implementation strategies tailored to address structural and social concerns to providing optimal care are needed to ensure that medical professionals are well versed in policy and clinical aspects.

A type II cannabis extract and a 1:1 blend of Δ(9)-tetrahydrocannabinol and cannabidiol display distinct antinociceptive profiles and engage different endocannabinoid targets when administered into the subarachnoid space

Introduction: Cannabis extracts are being increasingly used to mitigate chronic pain. Current guidelines for their prescription rely on Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) content as well as the ratio of these major cannabinoids present in the blend. Here we assessed whether these descriptors were representative of product effectiveness to produce a desired outcome such as analgesia. Methods: In this study, we used a rat model of diabetic neuropathy and assessed the reduction in mechanical allodynia following intrathecal injection of pure THC, pure CBD, a 1:1 mix of these compounds and a "balanced" chemotype II cannabis extract. Engagement of endocannabinoid targets by different treatments was investigated using CB1 (AM251) and CB2 (AM630) receptor antagonists as well as a TRPV1 channel blocker (capsazepine). Results: Antinociceptive responses induced by an equivalent amount of THC administered in its pure form, as a THC:CBD mix or as a "balanced" extract were distinct. Furthermore, the 1:1 THC:CBD mix and the balanced extract had not only different response profiles but their relative engagement of CB1, CB2 receptors and TRPV1 channels was distinct. Discussion: These findings indicate that antinociceptive responses and targets engaged by blended cannabinoids are composition-specific, and cannot be simply inferred from THC and CBD contents. This information may have implications in relation to the way medicinal cannabis products are prescribed.

Is Cannabis Effective in the Treatment of Chronic Back Pain?

Cannabis is commonly recognized as a recreational substance. It has been explored for its potential therapeutic applications in addressing various conditions, such as depression, anxiety, sleep disorders, neurological disorders, and chronic low back pain, which affect a significant portion of the population. In the United Kingdom, cannabis has been recognized and licensed for medical use since November 2018, with about 12 National Health Service prescriptions in circulation largely due to patient pressure, with support from media campaigns for its use when there was growing evidence of its use in intractable epilepsy. Cannabis is beginning to gain traction as an alternative or even a complementary drug to opiates with some pre-clinical studies showing opiate-sparing effects. Despite references to its therapeutic use, cannabis as a therapeutic drug has been controversial due to the negative perception of its use as a recreational drug. As a result, there have been challenges in changing the perception of healthcare authorities and clinicians on the use of cannabis as a therapeutic tool for pain relief. The stigma associated with cannabis could be responsible for the paucity of randomized controlled trials on the efficacy of medical cannabis, further decreasing the credibility of the few trials conducted.

Cannabis Unveiled: An Exploration of Marijuana's History, Active Compounds, Effects, Benefits, and Risks on Human Health

Marijuana, also known as cannabis, is a psychoactive drug that comes from the Cannabis plant. Marijuana can be smoked, vaporized, or consumed through edibles in a variety of ways. Perception changes, changes in mood, and problems with coordination are all possible side effects. Marijuana is used for both recreational and medical purposes to treat a variety of health conditions. The literature review on the effects of marijuana on the human body has increased in recent years as more states legalize its use. It is important to investigate the benefits and harmful effects of marijuana on individuals due to the widespread use of cannabis-derived substances like marijuana for medical, recreational, and combined purposes. The paper will review different aspects of marijuana in 4 main domains. A thorough discussion of marijuana's definition, history, mechanism of action, pharmacokinetics, and effects on human cells will be given in the first domain. The second domain will concentrate on marijuana's negative effects, while the third domain will look at marijuana's possible positive impacts, such as its usage in controlling multiple sclerosis, treating obesity, lowering social anxiety, and managing pain. The fourth domain will concentrate on marijuana's effects on anxiety, educational attainment, and social consequences. Additionally, this paper also will provide a highlight of the history of marijuana use and governmental legislation, both of which play a significant role in determining how the public views marijuana. In conclusion, this paper provides a comprehensive review of marijuana's effects, which may be of interest to a large readership. This review adds to the continuing discussion about the use of marijuana by analyzing the data that is currently available about the possible advantages and disadvantages of marijuana usage.

A cross-sectional survey of prospective healthcare professionals' knowledge, attitudes and perceptions of medical Cannabis

Background

Compounds isolated from Cannabis possess many beneficial effects creating a renewed worldwide interest in its therapeutic potential. With increased legalization for medicinal use globally, healthcare professionals must be familiar with the drug's uses and potential adverse effects.

Objective

To determine prospective healthcare providers' knowledge, attitude and perception to medical Cannabis.

Method

A self-administered online questionnaire comprising 21 questions to assess the knowledge, attitude and perception of medical Cannabis was distributed via google forms among students at the Faculty of Medical Sciences, the University of the West Indies, St Augustine Campus. Chi-square analysis was used to detect significant associations between demographics and measured variables. A p-value <0.05 was considered significant.

Results

Popular perceived therapeutic benefits of Cannabis were chronic pain (91.2%), anxiety (84.2%) and seizures (71.1%), and identification of the risks associated with the use of Cannabis was low. Users of Cannabis were able to identify indications and symptoms that can be treated with Cannabis but were less aware of the adverse effects of the drug than non-users (p < 0.001). More than three-quarters (87.3%) believed they could identify therapeutic uses and adverse effects but only 14.2% were ready to answer queries from patients. The main source of Cannabis information was the internet and information was lacking in the medical school curriculum.

Conclusion

The majority of students could not identify the drug's indications and adverse effects. There is a need to improve training for all prospective medical personnel to cater for the change in legislation status.

Cannabinoid Therapy: Attitudes and Experiences of People With Chronic Pain

OBJECTIVE

Clinical trials of cannabinoids for chronic pain have mixed and often inconclusive results. In contrast, many prospective observational studies show the analgesic effects of cannabinoids. This survey study aimed to examine the experiences/attitudes of individuals with chronic pain who are currently taking, have previously taken, or never taken cannabinoids for chronic pain to inform future research.

METHODS

This study is based on a cross-sectional, web-based survey of individuals with self-reported chronic pain. Participants were invited to participate through an email that was distributed to the listservs of patient advocacy groups and foundations that engage individuals with chronic pain.

RESULTS

Of the 969 respondents, 444 (46%) respondents reported currently taking, 213 (22%) previously taken, and 312 (32%) never taken cannabinoids for pain. Participants reported using cannabinoids to treat a wide variety of chronic pain conditions. Those currently taking cannabinoids (vs previously) more frequently reported: (1) large improvements from cannabinoids in all pain types, including particularly difficult-to-treat chronic overlapping pain conditions (eg, pelvic pain), (2) improvements in comorbid symptoms (eg, sleep), and (3) lower interference from side effects. Those currently taking cannabinoids reported more frequent and satisfactory communication with clinicians regarding cannabinoid use. Those never taken cannabinoids reported a lack of suggestion/approval of a clinician (40%), illegality (25%), and lack of FDA regulation (19%) as reasons for never trying cannabinoids.

CONCLUSION

These findings underscore the importance of conducting high-quality clinical trials that include diverse pain populations and clinically relevant outcomes that if successful, could support FDA approval of cannabinoid products. Clinicians could then prescribe and monitor these treatments similarly to other chronic pain medications.

Women are Taking the Hit: Examining the Unique Consequences of Cannabis Use Across the Female Lifespan

Cannabis use has risen dramatically in recent years due to global decriminalization and a resurgence in the interest of potential therapeutic benefits. While emerging research is shaping our understanding of the benefits and harms of cannabis, there remains a paucity of data specifically focused on how cannabis affects the female population. The female experience of cannabis use is unique, both in the societal context and because of the biological ramifications. This is increasingly important given the rise in cannabis potency, as well as the implications this has for the prevalence of Cannabis Use Disorder (CUD). Therefore, this scoping review aims to discuss the prevalence of cannabis use and CUD in women throughout their lifespan and provide a balanced prospective on the positive and negative consequences of cannabis use. In doing so, this review will highlight the necessity for continued research that goes beyond sex differences.

Using Medical Cannabis for Chronic Pain: A Social-Ecological Framework

Early studies suggest medical cannabis (MC) has the potential to benefit people who suffer from chronic pain by offering a less addictive alternative to opioids; however, most investigators agree more research is indicated. Today, in 2023, cannabis remains a Schedule I drug and is an illegal substance in the United States under the Controlled Substances Act of 1970. Despite this designation, as of February 2022, 37 states, three territories, and the District of Columbia allowed using cannabis products to treat certain painful medical conditions. The contradictory status of federal and state legislation regarding cannabis use has resulted in delays and restrictions on relevant research. As a result, an inadequate foundation of knowledge exists needed to inform policy, program, and practice decisions concerning MC to treat pain. Implementing and controlling access to MC is influenced by overlapping individual, interpersonal, community, and organizational influences that all fall under the umbrella of federal and state policies. Increasingly, the legalization and expanded access to MC necessitates the integration of evidence, policy, and social-ecological reality. To adequately delineate these complex factors to anticipate and plan future interventions at multiple levels, we propose a social-ecological framework (SEF) for using MC to treat pain. This SEF assumes the transactional relationship between the individual and the environment and that no single factor can predict behavior or health outcomes. Our framework illustrates five dynamic levels of analysis that interact between dimensions. Key elements and intersections are discussed at the intrapersonal, interpersonal, institutional, community, and policy levels.

Towards dsRNA-integrated protection of medical Cannabis crops: considering human safety, recent- and developing RNAi methods, and research inroads

Owing to the expanding industry of medical Cannabis, we discuss recent milestones in RNA interference (RNAi)-based crop protection research and development that are transferable to medical Cannabis cultivation. Recent and prospective increases in pest pressure in both indoor and outdoor Cannabis production systems, and the need for effective nonchemical pest control technologies (particularly crucial in the context of cultivating plants for medical purposes), are discussed. We support the idea that developing RNAi tactics towards protection of medical Cannabis could play a major role in maximizing success in this continuously expanding industry. However, there remain critical knowledge gaps, especially with regard to RNA pesticide biosafety from a human toxicological viewpoint, as a result of the medical context of Cannabis product use. Furthermore, efforts are needed to optimize transformation and micropropagation of Cannabis plants, examine cutting edge RNAi techniques for various Cannabis-pest scenarios, and investigate the combined application of RNAi- and biological control tactics in medical Cannabis cultivation. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A national population-based study of cannabis use and correlates among U.S. veterans prescribed opioids in primary care

BACKGROUND

Cannabis is marketed as a treatment for pain. There is limited data on the prevalence of cannabis use and its correlates among Veterans prescribed opioids.

OBJECTIVE

To examine the prevalence and correlates of cannabis use among Veterans prescribed opioids.

DESIGN

Cross-sectional study.

PARTICIPANTS

Veterans with a urine drug test (UDT) from Primary Care 2014-2018, in 50 states, Washington, D.C., and Puerto Rico. A total of 1,182,779 patients were identified with an opioid prescription within 90 days prior to UDT.

MAIN MEASURES

Annual prevalence of cannabis positive UDT by state. We used multivariable logistic regression to assess associations of demographic factors, mental health conditions, substance use disorders, and pain diagnoses with cannabis positive UDT.

RESULTS

Annual prevalence of cannabis positive UDT ranged from 8.5% to 9.7% during the study period, and in 2018 was 18.15% in Washington, D.C. and 10 states with legalized medical and recreational cannabis, 6.1% in Puerto Rico and 25 states with legalized medical cannabis, and 4.5% in non-legal states. Younger age, male sex, being unmarried, and marginal housing were associated with use (p < 0.001). Post-traumatic stress disorder (adjusted odds ratio [AOR] 1.17; 95% confidence interval [CI] 1.13-1.22, p < 0.001), opioid use disorder (AOR 1.14; CI 1.07-1.22, p < 0.001), alcohol use disorder or positive AUDIT-C (AOR 1.34; 95% CI 1.28-1.39, p < 0.001), smoking (AOR 2.58; 95% CI 2.49-2.66, p < 0.001), and other drug use disorders (AOR 1.15; 95% CI 1.03-1.29, p = 0.02) were associated with cannabis use. Positive UDT for amphetamines AOR 1.41; 95% CI 1.26-1.58, p < 0.001), benzodiazepines (AOR 1.41; 95% CI 1.31-1.51, p < 0.001) and cocaine (AOR 2.04; 95% CI 1.75-2.36, p < 0.001) were associated with cannabis positive UDT.

CONCLUSIONS

Cannabis use among Veterans prescribed opioids varied by state and by legalization status. Veterans with PTSD and substance use disorders were more likely to have cannabis positive UDT. Opioid-prescribed Veterans using cannabis may benefit from screening for these conditions, referral to treatment, and attention to opioid safety.

ASRA Pain Medicine consensus guidelines on the management of the perioperative patient on cannabis and cannabinoids

BACKGROUND

The past two decades have seen an increase in cannabis use due to both regulatory changes and an interest in potential therapeutic effects of the substance, yet many aspects of the substance and their health implications remain controversial or unclear.

METHODS

In November 2020, the American Society of Regional Anesthesia and Pain Medicine charged the Cannabis Working Group to develop guidelines for the perioperative use of cannabis. The Perioperative Use of Cannabis and Cannabinoids Guidelines Committee was charged with drafting responses to the nine key questions using a modified Delphi method with the overall goal of producing a document focused on the safe management of surgical patients using cannabinoids. A consensus recommendation required ≥75% agreement.

RESULTS

Nine questions were selected, with 100% consensus achieved on third-round voting. Topics addressed included perioperative screening, postponement of elective surgery, concomitant use of opioid and cannabis perioperatively, implications for parturients, adjustment in anesthetic and analgesics intraoperatively, postoperative monitoring, cannabis use disorder, and postoperative concerns. Surgical patients using cannabinoids are at potential increased risk for negative perioperative outcomes.

CONCLUSIONS

Specific clinical recommendations for perioperative management of cannabis and cannabinoids were successfully created.

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

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.

Measurement of Δ9THC and metabolites in the brain and peripheral tissues after intranasal instillation of a nanoformulation

BACKGROUND

Comparative bioavailability of cannabinoids following their administration by dosing routes has been studied previously, but there are no quantitative reports of distribution of Δ⁹THC, nor its metabolites, across various brain regions following intranasal (i.n.) administration. The aim of the present study was to determine the time course of Δ⁹THC transport from nose to brain and to quantify the distribution of Δ⁹THC and its metabolites in four brain regions.

METHODS

Δ⁹THC was formulated as a lipophilic nano-emulsion and instilled i.n. to three groups of adult mice and euthanized after 2, 4, and 8 h. Brains were dissected into 4 regions. Sensitive analytical methods (HPLC-MS) were utilized to quantify levels of Δ⁹THC and metabolites in brain regions and peripheral tissues. Data was expressed as mean concentrations (± SEM) of Δ⁹THC and metabolites in brain regions, blood, plasma, urine, and liver. Two-way analysis of variance was performed followed by post hoc multiple comparisons.

RESULTS

Peak concentrations of Δ⁹THC were reached at 2 h in the brain (15.9 ng/mg), blood (4.54 μg/mL), and plasma (4.56 μg /mL). The percentage of administered dose of Δ⁹THC transported to the brain (5.9%) was greater than in blood (1.7%), plasma (1.6%), urine (0.4%), and liver (0.1%). Concentrations of Δ⁹THC and its THC-COOH metabolite in the liver reached their highest levels at 8 h.

DISCUSSION

The present study is the first to report the uptake and distribution across brain regions of Δ⁹THC and its principal metabolites following i.n. administration. The systemic bioavailability (absorption into the blood) of intranasal Δ⁹THC was 1.7% of the administered dose, much lower than that reported by others after oral ingestion (7-10%) and inhalation (20-35%), but those prior studies did not measure the transport of Δ⁹THC into brain regions. Others have reported Δ⁹THC in the whole brain following i.n. instillation in a different species (rats) to be twice (5.9%) that following i.p. injections, while metabolites of Δ⁹THC in rat brain were lower after i.n. administration.

CONCLUSIONS

The intranasal route of a Δ⁹THC nanoformulation is an effective way to deliver cannabinoids to the brain, especially in those who cannot take the medication orally. Going forward, a metered dosing nasal spray will provide accurate and consistent doses.

Cannabinoids to Improve Health-Related Quality of Life in Patients with Neurological or Oncological Disease: A Meta-Analysis

Background: Cannabinoids have been suggested to alleviate frequently experienced symptoms of reduced mental well-being such as anxiety and depression. Mental well-being is an important subdomain of health-related quality of life (HRQoL). Reducing symptoms and maintaining HRQoL are particularly important in malignant primary brain tumor patients, as treatment options are often noncurative and prognosis remains poor. These patients frequently report unprescribed cannabinoid use, presumably for symptom relieve. As studies on brain tumor patients specifically are lacking, we performed a meta-analysis of the current evidence on cannabinoid efficacy on HRQoL and mental well-being in oncological and neurological patients. Methods: We performed a systematic PubMed, PsychINFO, Embase, and Web of Science search according to PRISMA guidelines on August 2 and 3, 2021. We included randomized controlled trials (RCTs) that assessed the effects of tetrahydrocannabinol (THC) or cannabidiol (CBD) on general HRQoL and mental well-being. Pooled effect sizes were calculated using Hedges g. Risk of bias of included studies was assessed using Cochrane's Risk of Bias tool. Results: We included 17 studies: 4 in oncology and 13 in central nervous system (CNS) disease. Meta-analysis showed no effect of cannabinoids on general HRQoL (g=-0.02 confidence interval [95% CI -0.11 to 0.06]; p=0.57) or mental well-being (g=-0.02 [95% CI -0.16 to 0.13]; p=0.81). Conclusions: RCTs in patients with cancer or CNS disease showed no effect of cannabinoids on HRQoL or mental well-being. However, studies were clinically heterogeneous and since many glioma patients currently frequently use cannabinoids, future studies are necessary to evaluate its value in this specific population.

The antinociceptive activity and mechanism of action of cannabigerol

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.

Functional consequences of short-term exposure to opioids versus cannabinoids in nonhuman primates

Opioids provide pain relief but are associated with several adverse effects. Researchers are exploring cannabis-based medicine as an alternative. However, little is known about the tendency for physical dependence on cannabinoids in comparison with that on opioids in primates. The aim of this study was to compare the potency of heroin and delta-9-tetrahydrocannabinol (THC) in eliciting analgesic effects and the development of physical dependence between opioids and cannabinoids in both male and female rhesus monkeys. Systemic administration of either heroin (0.03-0.18 mg/kg) or THC (0.3-1.8 mg/kg) in a dose-dependent manner produced antinociceptive effects against an acute thermal nociceptive stimulus. The μ-opioid receptor antagonist naltrexone (0.01 mg/kg) and the cannabinoid receptor antagonist SR141716A (0.3 mg/kg) produced the same degree of rightward shift in the dose-response curves for heroin- and THC-induced antinociception, respectively. Monkeys implanted with telemetry devices were subjected to short-term repeated administrations (two injections per day for 1-3 days) of either heroin (0.18 mg/kg), morphine (1.8 mg/kg), THC (1.8 mg/kg), or CP 55,940 (0.032 mg/kg). Administration of naltrexone (0.01 mg/kg) increased respiration, heart rate, and blood pressure in heroin- or morphine-treated monkeys. In contrast, administration of SR141716A (0.3 mg/kg) did not cause a significant change in these physiological parameters in THC- or CP 55,940-treated monkeys. Additionally, morphine, but not CP 55,940, enhanced the monkeys' hypersensitivity to the algogen capsaicin. Collectively, these results demonstrate that in nonhuman primates, both opioids and cannabinoids exert comparable antinociception; however, physical dependence on opioids, but not cannabinoids, at their antinociceptive doses, occurs following short-term exposures.

Intimate partner violence, substance use, and health comorbidities among women: A narrative review

Exposure to intimate partner violence (IPV), including physical, sexual, and psychological violence, aggression, and/or stalking, impacts overall health and can have lasting mental and physical health consequences. Substance misuse is common among individuals exposed to IPV, and IPV-exposed women (IPV-EW) are at-risk for transitioning from substance misuse to substance use disorder (SUD) and demonstrate greater SUD symptom severity; this too can have lasting mental and physical health consequences. Moreover, brain injury is highly prevalent in IPV-EW and is also associated with risk of substance misuse and SUD. Substance misuse, mental health diagnoses, and brain injury, which are highly comorbid, can increase risk of revictimization. Determining the interaction between these factors on the health outcomes and quality of life of IPV-EW remains a critical need. This narrative review uses a multidisciplinary perspective to foster further discussion and research in this area by examining how substance use patterns can cloud identification of and treatment for brain injury and IPV. We draw on past research and the knowledge of our multidisciplinary team of researchers to provide recommendations to facilitate access to resources and treatment strategies and highlight intervention strategies capable of addressing the varied and complex needs of IPV-EW.

Microglial Cannabinoid CB2 Receptors in Pain Modulation

Pain, especially chronic pain, can strongly affect patients' quality of life. Cannabinoids ponhave been reported to produce potent analgesic effects in different preclinical pain models, where they primarily function as agonists of G_i/o protein-coupled cannabinoid CB₁ and CB₂ receptors. The CB₁ receptors are abundantly expressed in both the peripheral and central nervous systems. The central activation of CB₁ receptors is strongly associated with psychotropic adverse effects, thus largely limiting its therapeutic potential. However, the CB₂ receptors are promising targets for pain treatment without psychotropic adverse effects, as they are primarily expressed in immune cells. Additionally, as the resident immune cells in the central nervous system, microglia are increasingly recognized as critical players in chronic pain. Accumulating evidence has demonstrated that the expression of CB₂ receptors is significantly increased in activated microglia in the spinal cord, which exerts protective consequences within the surrounding neural circuitry by regulating the activity and function of microglia. In this review, we focused on recent advances in understanding the role of microglial CB₂ receptors in spinal nociceptive circuitry, highlighting the mechanism of CB₂ receptors in modulating microglia function and its implications for CB₂ receptor- selective agonist-mediated analgesia.

Use of Marijuana to Promote Well-Being: Effects of Use and Prohibition in the Daily Lives of Brazilian Adults

Background

Marijuana is the most widely used illicit drug worldwide. From an occupational perspective, its use is paradoxical in that although it can be harmful to health and has criminal consequences, it can also promote well-being. This study examined predictors of well-being to determine the effects of marijuana use and its prohibition on the daily lives of Brazilian adults.

Methods

This cross-sectional study used an anonymous online questionnaire with a final sample of 2637 respondents. Utilizing logistic regression, variables were selected pertaining to use and prohibition risks, benefits of use, and harm reduction associated with the socioeconomic characteristics of the respondents.

Results

Using marijuana for fun was most likely among those self-identified as male, trans/non-binary people, college graduates, and those with higher incomes. Living with family members and using less frequently proved to be protective against the adverse effect of "getting high." Indigenous peoples and youth were more likely to report trouble with the police due to marijuana use; individuals with higher education and longer use of marijuana reported more frequent use of harm reduction strategies; people who identified their color as yellow were more likely to report daily use compared to people who identified their color as white; women and people with higher income were less likely to report daily use.

Conclusions

Social class, race, gender, and generation were predictors of well-being associated with marijuana use and its prohibition, indicating an interaction between different dimensions involving the use of illicit substances. Identifying the effects of the use and prohibition of marijuana in promoting well-being, from the conception of drug use as a non-sanctioned occupation, can broaden the understanding of this complex human phenomenon, with health and criminal repercussions, subsidizing the development of approaches more equitable and adequate into occupational therapy to reduce personal and social harm.

Prevention, Practice, and Policy: Older US Veterans' Perspectives on Cannabis Use

BACKGROUND AND OBJECTIVE

Veterans often struggle with disabling physical and mental health conditions that tend to worsen as they age. Current medications used to treat these conditions include opioids and benzodiazepines though they can have negative side effects. Looking for alternatives to these medications, many older Veterans use cannabis for medical purposes. We aimed to develop a deeper understanding of older Veterans' cannabis use.

METHODS

We used maximum variation sampling to select 32 Veterans who had completed baseline and follow-up surveys to participate in semi-structured interviews.

RESULTS

After applying a thematic analysis, results show older Veterans are using medical cannabis as a means of harm reduction as an adjunct or substitute for other medications and substances with limited guidance from their healthcare providers. Veterans also reported that there exists an inconsistency across the Veterans Health Administration system regarding the interpretation and application of cannabis policies.

CONCLUSIONS

Drawing from these findings, we explore medical cannabis as a harm reduction technique and discuss how a lack of physician engagement and current Veterans Health Administration policies discourage older Veterans from discussing and potentially benefiting from the use of medical cannabis.

The C4EB study-Transvamix (10% THC / 5% CBD) to treat chronic pain in epidermolysis bullosa: A protocol for an explorative randomized, placebo controlled, and double blind intervention crossover study

Patients with the genetic blistering skin condition epidermolysis bullosa (EB) report severe pain as a consequence of skin and mucous membrane lesions including blisters, wounds, and scars. Adequate symptom alleviation is not often achieved using conventional pharmacologic interventions. Finding novel approaches to pain care in EB is imperative to improve the quality of life of patients living with EB. There are several anecdotal reports on the use of cannabinoid-based medicines (CBMs) by EB patients to reduce the burden of symptoms. However, controlled clinical investigations assessing these reported effects are lacking. As the pain quality "unpleasantness" delineates EB pain, we hypothesize the modulation of affective pain processing in the brain by way of intervention with CBMs comprising the cannabinoids Δ-9-tetrahydrocannabinol and cannabidiol-objectified by functional magnetic resonance imaging (fMRI). The C4EB study is an investigator-initiated, single-centre, randomized, double-blind, placebo-controlled and crossover trial. Adult patients with the diagnosis epidermolysis bullosa, reporting chronic pain will be eligible to participate. Following baseline measurements, participants will be randomized to receive the sublingually administered interventions placebo and Transvamix® in forward or reversed orders, each for two weeks and separated by a washout. The primary outcome is the difference in numeric rating scale pain scores between grouped interventions, using affective descriptors within the Short-form McGill Pain Questionnaire-2. Secondary outcomes include pain self-efficacy, concomitant analgesic medication-use and adverse events. Additionally, fMRI will be employed to assess brain connectivity related to neuroanatomic pain circuits at baseline, placebo and Transvamix® interventions. The study was approved by the ethical committee at the University Medical Center of Groningen in the Netherlands. Results will be submitted for publication in a peer-reviewed journal. Trial registration number: Netherlands Trial Register: NL9347 (Acronym: C4EB).

A reliable quantitative method for determining CBD content and release from transdermal patches in Franz cells

INTRODUCTION

There are several cannabidiol (CBD) transdermal patches available on the market. However, none are FDA-approved. Furthermore, not much evidence has been published about CBD release and skin permeation from such patches, so the effectiveness and reliability remain unclear.

OBJECTIVES

We aimed to develop a method to determine the in vitro release and skin permeation of CBD from transdermal patches using Franz cell diffusion in combination with quantitative ¹ H-NMR (qNMR).

MATERIALS AND METHODS

The study was conducted on CBD patches with known CBD content and six different commercially available or market-ready CBD patches using a Franz cell with a Strat-M™ membrane and with samples taken directly from the transdermal patch for qNMR analysis.

RESULTS

The use of qNMR yielded an average recovery of 100% ± 7% when samples with known CBD content were tested. Results from the testing of six commercially available patches indicated that five out of six patches did not contain the CBD amount stated by the manufacturer according to a ± 10% variance margin, of which four patches were under-labeled and one was over-labeled. The release rate of patches was determined, and significant differences between the patches were shown. Maximum release of CBD was calculated to occur after 39 to 70 h.

CONCLUSION

The established method was proven to be a reliable means of determining the quantity and release of CBD from transdermal patches and can be used to verify CBD content and release rate in transdermal patches.

Association of cannabis and/or opioid with quality of life and healthcare utilization in patients with chronic pain

Background

Opioids have been commonly used to treat chronic pain, but they are associated with significant morbidity and mortality. Cannabis has been advocated as an alternative; however, a growing number of patients are now using a combination of opioid and cannabis and the impact of this combination is not well-studied.

Aim

We characterized use of opioid and/or cannabis in patients with chronic pain; and compared utilization of healthcare resources.

Methods

We conducted a cross-sectional study to determine if measures of physical, psychological and social functioning differed among patients according to whether they used opioids and/or cannabis. We used our learning healthcare system - CHOIR - to capture NIH Patient Reported Outcomes Measure Information System surveys, and legacy pain and treatment specific questions.

Results

Patients who report use of opioid and/or cannabis experience higher levels of physical, psychological and social distress. After adjusting for inversed weight of propensity scores, they have higher odds of visiting an emergency room, staying overnight at the hospital, and visiting a physician.

Conclusion

Our results show that use of opioid and/or cannabis is associated with worse baseline characteristics and outcomes. Our study however cannot determine if worse outcomes are due to the opioids and/or cannabis or simply that these patients are worse off before using opioids and/or cannabis. Thus, it is important to characterize the trajectory of these patients in a prospective longitudinal study.

Validation of the Motivational Inventory Underlying Substance Use Engagement (MI-USE)

Given the growing number of fatalities associated with the use of multiple types of drugs, there is an urgent need for a tool that allows clinicians and researchers to quickly assess diverse reasons for substance use. Here, we sought to validate the Motivational Inventory Underlying Substance Engagement (MI-USE), a new measure that assesses motivations for use across different types of substances. Participants were 538 adults ages 18-60 (48% women) who reported substance use problems and past-year drug or alcohol use. Analyses were conducted to discover and validate the factor structure of the MI-USE and evaluate its construct validity. A 30-item model best fit the MI-USE, with one General Factor capturing overall motivation to engage in substance use and eight motive-specific factors that indexed unique motivations for substance use: Emotional Coping (relief from unpleasant emotions), Pleasure-Seeking (feel pleasurable or exciting emotions and sensations), Dependence Severity (avoid withdrawal and cravings), Expansion (enhance self-insight and spirituality), Social Coping (increase confidence and attractiveness), Advantage (gain a physical or mental advantage), Physical Coping (relief from unpleasant bodily sensations), and Sleep (mitigate sleep problems). Evaluation of the measure's construct validity and internal consistency support the chosen model and interpretation of the motive-specific factors. Results provide initial validation of the MI-USE as a reliable and valid tool for assessing diverse substance use motivations. It improves upon existing measures by allowing clinicians and researchers to simultaneously evaluate motivations for multiple forms of substance use, which facilitates personalized treatment planning and research on polysubstance use.

Practical Considerations for the Use of Cannabis in Cancer Pain Management—What a Medical Oncologist Should Know

Pain is a highly debilitating emotional and sensory experience that significantly affects quality of life (QoL). Numerous chronic conditions, including cancer, are associated with chronic pain. In the setting of malignancy, pain can be a consequence of the tumor itself or of life-saving interventions, including surgery, chemotherapy, and radiotherapy. Despite significant pharmacological advances and awareness campaigns, pain remains undertreated in one-third of patients. To date, opioids have been the mainstay of cancer pain management. The problematic side effects and unsatisfactory pain relief of opioids have revived patients’ and physicians’ interest in finding new solutions, including cannabis and cannabinoids. The medical use of cannabis has been prohibited for decades, and it remains in Schedule 1 of the Misuse of Drugs Regulations. Currently, the legal context for its usage has become more permissive. Various preclinical and observational studies have aimed to prove that cannabinoids could be effective in cancer pain management. However, their clinical utility must be further supported by high-quality clinical trials.

Peroxisome proliferator-activated receptor gamma agonist ELB00824 suppresses oxaliplatin-induced pain, neuronal hypersensitivity, and oxidative stress

Chemotherapy-induced neuropathic pain (CINP) is a debilitating and difficult-to-treat side effect of chemotherapeutic drugs. CINP is marked with oxidative stress and neuronal hypersensitivities. The peroxisome proliferator-activated receptor gamma (PPARγ) is a transcription factor that regulates genes involved in oxidative stress and inflammation. We hypothesize that PPARγ agonists are protective against CIPN by reducing oxidative stress and inhibiting neuronal hypersensitivities. To test our hypothesis, acute or chronic CIPN was introduced by short or long-term treatment of oxaliplatin in BALB/c mice. CIPN mice were treated with either a novel blood-brain barrier (BBB) penetrable PPARγ agonist ELB00824, or a BBB non-penetrable PPARγ agonist pioglitazone, or vehicle. Cold allodynia, mechanical allodynia, motor coordination, sedation and addiction were measured with dry ice, von Frey filaments, beam-walking tests, and conditioned place preference, respectively. Oxidative stress was accessed by measuring byproducts of protein oxidation (carbonyl and 3-Nitrotyrosine) and lipid peroxidation [Thiobarbituric acid reactive substances (TBARS)], as wells as gene expression of Cat, Sod2, Ppargc1a. The effects of ELB00824 on nociceptor excitability were measured using whole-cell electrophysiology of isolated dorsal root ganglion neurons. Preemptive ELB00824, but not pioglitazone, reduced oxaliplatin-induced cold and mechanical allodynia and oxidative stress. ELB0824 suppressed oxaliplatin-induced firing in IB4^- neurons. ELB00824 did not cause motor discoordination or sedation/addiction or reduce the antineoplastic activity of oxaliplatin (measured with an MTS-based cell proliferation assay) in a human colon cancer cell line (HCT116) and a human oral cancer cell line (HSC-3). Our results demonstrated that ELB00824 prevents oxaliplatin-induced pain, likely via inhibiting neuronal hypersensitivities and oxidative stress.

Systematic reviews of randomized controlled trials of cannabinoid products in chronic pain conditions and for symptoms associated with multiple sclerosis: what do they tell us?

INTRODUCTION

: To investigate whether published systematic reviews of randomized controlled trials provide sufficient clarity to inform prescribing of cannabinoid products aimed for medicinal use, we examined their features and findings in two well-researched areas: chronic cancer/noncancer pain and multiple sclerosis (MS)-related symptoms.

AREAS COVERED

: Structured searches from January 2011 to 2 February 2021 identified 31 systematic reviews (with/without meta-analyses) that met the inclusion criteria. Support for the efficacy of cannabinoids was minimal in cancer pain, and somewhat stronger in noncancer (especially neuropathic) pain and MS spasticity. All systematic reviews and most meta-analyses grouped cannabinoid products together without appropriate consideration of their differential attributes (active constituent(s), concentration/strength, dosage forms, administration route), dosing regimens or treatment durations. Patient populations and efficacy outcome measures were inhomogeneous, particularly for studies in noncancer pain and MS. Separate results for specific cannabinoid formulations were rarely provided.

EXPERT OPINION

: The therapeutic effect of cannabinoids, as already demonstrated for some products, is not reflected clearly in the current range of systematic reviews and meta-analyses in chronic pain and MS. To truly inform evidence-based practice, future publications should aim to present results by individual product from well-conducted clinical trials using appropriate and homogeneous outcome measures in well-defined patient populations.

Cannabinoid receptor 1 antagonist genistein attenuates marijuana-induced vascular inflammation

Epidemiological studies reveal that marijuana increases the risk of cardiovascular disease (CVD); however, little is known about the mechanism. Δ⁹-tetrahydrocannabinol (Δ⁹-THC), the psychoactive component of marijuana, binds to cannabinoid receptor 1 (CB1/CNR1) in the vasculature and is implicated in CVD. A UK Biobank analysis found that cannabis was an risk factor for CVD. We found that marijuana smoking activated inflammatory cytokines implicated in CVD. In silico virtual screening identified genistein, a soybean isoflavone, as a putative CB1 antagonist. Human-induced pluripotent stem cell-derived endothelial cells were used to model Δ⁹-THC-induced inflammation and oxidative stress via NF-κB signaling. Knockdown of the CB1 receptor with siRNA, CRISPR interference, and genistein attenuated the effects of Δ⁹-THC. In mice, genistein blocked Δ⁹-THC-induced endothelial dysfunction in wire myograph, reduced atherosclerotic plaque, and had minimal penetration of the central nervous system. Genistein is a CB1 antagonist that attenuates Δ⁹-THC-induced atherosclerosis.

Serotonin mediates stress-like effects on responses to non-nociceptive stimuli in Hirudo

Noxious stimuli can elicit stress in animals that produce a variety of adaptations including changes in responses to nociceptive and non-nociceptive sensory input. One example is stress-induced analgesia that may be mediated, in part, by the endocannabinoid system. However, endocannabinoids can also have pro-nociceptive effects. In this study, the effects of electroshock, one experimental approach for producing acute stress, were examined on responses to non-nociceptive mechanical stimuli and nociceptive thermal stimuli in the medicinal leech (Hirudo verbana). The electroshock stimuli did not alter the leeches’ responses to nociceptive stimuli, but did cause sensitization to non-nociceptive stimuli, characterized by a reduction in response threshold. These experiments were repeated with drugs that either blocked synthesis of the endocannabinoid transmitter 2-arachidonoylglycerol (2-AG) or transient receptor potential vanilloid (TRPV) channel, which is known to act as an endocannabinoid receptor. Surprisingly, neither treatment had any effect on responses following electroshock. However, the electroshock stimuli reliably increased serotonin (5-hydroxytryptamine or 5HT) levels in the H. verbana CNS. Injection of 5HT mimicked the effects of the electroshocks, sensitizing responses to non-nociceptive stimuli and having no effect on responses to nociceptive stimuli. Injections of the 5HT receptor antagonist methysergide reduced the sensitization effect to non-nociceptive stimuli after electroshock treatment. These results indicate that electroshocks enhance response to non-nociceptive stimuli but do not alter responses to nociceptive stimuli. Furthermore, while 5HT appears to play a critical role in this shock-induced sensitizing effect, the endocannabinoid system seems to have no effect.

Summary: The role of serotonin and endocannabinoids in mediating the effects of potentially stress-inducing stimuli on Hirudo verbana’s response to nociceptive and non-nociceptive input.

Advances in the management of fibromyalgia: what is the state of the art?

INTRODUCTION

Fibromyalgia (FM) is a chronic pain syndrome associated with fatigue, insomnia, dyscognition, and emotional distress. Critical illness mechanisms include central sensitization to nociceptive and non-nociceptive stimuli often resulting in hypersensitivity to all sensory input.

AREAS COVERED

The clinical presentation of FM can vary widely and therefore requires therapies tailored to each patient's set of symptoms. This manuscript examines currently prescribed therapeutic approaches supported by empirical evidence as well as promising novel treatments. Although pharmacological therapy until now has been only moderately effective for FM symptoms, it represents a critical component of every treatment plan.

EXPERT OPINION

Currently approved pharmacological therapies for FM symptoms have limited but proven effectiveness. Novel therapies with cannabinoids and naltrexone appear promising. Recent functional imaging studies of FM have discovered multiple brain network abnormalities that may provide novel targets for mechanism-based therapies. Future treatment approaches, however, need to improve more than clinical pain but also other FM domains like fatigue, insomnia, and distress.

Effect of Fatty Acid Amide Hydrolase Inhibitor URB597 on Orofacial Pain Perception in Rats

Endocannabinoids act as analgesic agents in a number of headache models. However, their effectiveness varies with the route of administration and the type of pain. In this study, we assessed the role of the fatty acid amide hydrolase inhibitor URB597 in an animal model of orofacial pain based on tooth pulp stimulation. More specifically, we assessed the effects of intracerbroventricular (i.c.v.) and intraperitoneal (i.p.) administration of URB597 on the amplitude of evoked tongue jerks (ETJ) in rats. The levels of the investigated mediators anandamide (AEA), 2-arachidonyl glycerol (2-AG), Substance P (SP), calcitonin-gene-related peptide (CGRP), endomorphin-2 (EM-2) and fatty acid amide hydrolase (FAAH) inhibitor by URB597 and receptors cannabinoid type-1 receptors (CB1R), cannabinoid type-2 receptors (CB2R) and µ-opioid receptors (MOR) were determined in the mesencephalon, thalamus and hypothalamus tissues. We have shown that increasing endocannabinoid AEA levels by both central and peripheral inhibition of FAAH inhibitor by URB597 has an antinociceptive effect on the trigemino-hypoglossal reflex mediated by CB1R and influences the activation of the brain areas studied. On the other hand, URB597 had no effect on the concentration of 2-AG in the examined brain structures and caused a significant decrease in CB2R mRNA expression in the hypothalamus only. Tooth pulp stimulation caused in a significant increase in SP, CGRP and EM-2 gene expression in the midbrain, thalamus and hypothalamus. In contrast, URB597 administered peripherally one hour before stimulation decreased the mRNA level of these endogenous neuropeptides in comparison with the control and stimulation in all examined brain structures. Our results show that centrally and peripherally administered URB597 is effective at preventing orofacial pain by inhibiting AEA catabolism and reducing the level of CGRP, SP and EM-2 gene expression and that AEA and 2-AG have different species and model-specific regulatory mechanisms. The data presented in this study may represent a new promising therapeutic target in the treatment of orofacial pain.

Association between cannabis use and physical health problems in Norwegian adolescents: a cross-sectional study from the youth survey Ungdata

Background

Cannabis use is increasing among young Norwegians and several studies show a high incidence of common physical health problems. An association has previously been found between cannabis use and mental health problems. Since physical and mental health problems often co-occur, the aim of this study is to explore the relationship between cannabis use and physical health problems.

Methods

In 2017–2019, the Norwegian youth survey Ungdata collected data from 249,100 Norwegian adolescents, which equalled around 80% of all lower secondary school pupils (13–15 years) and about 50% of upper secondary pupils (16–19 years) in Norway. Descriptive analysis was used to calculate the prevalence of cannabis use and bi- and multivariate logistic regression analysis to examine the association between cannabis use and physical health problems, controlled for sociodemographics and mental health problems.

Results

Almost 10% of Norwegian adolescents had used cannabis once or more in the previous 12 months. The use of cannabis increased with age and it was more prevalent among boys. There is a clear connection between physical health problems and cannabis use (OR = 1.582 (CI: 1.527–1.638)) even after adjusting for sociodemographic variables and mental health problems (OR = 1.366 (CI: 1.312–1.423)).

Conclusion

More studies are needed to explore if there might a bidirectional relationship between cannabis use and physical health problems where physical problems increase cannabis use and cannabis use increases the risk of physical health problems. More knowledge on the effect of and motivation for cannabis use are important for policy makers and health care professionals involved in young people.

Approaches to studying injury-induced sensitization and the potential role of an endocannabinoid transmitter

Endocannabinoids are traditionally thought to have an analgesic effect. However, it has been shown that while endocannabinoids can depress nociceptive signaling, they can also enhance non-nociceptive signaling. Therefore, endocannabinoids have the potential to contribute to non-nociceptive sensitization after an injury. Using Hirudo verbana (the medicinal leech), a model of injury-induced sensitization was developed in which a reproducible piercing injury was delivered to the posterior sucker of Hirudo. Injury-induced changes in the non-nociceptive threshold of Hirudo were determined through testing with Von Frey filaments and changes in the response to nociceptive stimuli were tested by measuring the latency to withdraw to a nociceptive thermal stimulus (Hargreaves apparatus). To test the potential role of endocannabinoids in mediating injury-induced sensitization, animals were injected with tetrahydrolipstatin (THL), which inhibits synthesis of the endocannabinoid transmitter 2-arachidonoylglycerol (2-AG). Following injury, a significant decrease in the non-nociceptive response threshold (consistent with non-nociceptive sensitization) and a significant decrease in the response latency to nociceptive stimulation (consistent with nociceptive sensitization) were observed. In animals injected with THL, a decrease in non-nociceptive sensitization in injured animals was observed, but no effect on nociceptive sensitization was observed.