Cannabis for Rheumatic Disease Pain: a Review of Current Literature

The emerging role of endocannabinoid system modulation in human fibroblast-like synoviocytes: Exploring new biomarkers and potential therapeutic targets

Human fibroblast-like synoviocytes (HFLS) are the predominant cellular component of the joint synovium. Their inflammation, known as synovitis, may contribute to the development of osteoarthritis (OA). HFLS secrete signaling factors that regulate joint function in response to mechanical trauma or OA progression. Among these factors, prostaglandin E2 (PGE2) is a key pro-inflammatory mediator, whereas prostamides, such as prostamide E2 (PME2), are synthesized from anandamide (AEA) by the same enzymes that produce PGE2. HFLS were isolated from both control subjects and OA patients (HFLS-OA) and stimulated with lipopolysaccharide (LPS, 10 ng/mL). Liquid chromatography-tandem mass spectrometry (LC-MS) was used to analyze PGE2 and PME2 secretion. Additionally, transcriptome and miRNA sequencing were conducted to identify changes in gene expression between HFLS and HFLS-OA cells. Five endocannabinoid-related genes were further validated by qPCR. Baseline PGE2 secretion differed between HFLS and HFLS-OA, with OA-related cells showing increased levels, while control cells primarily produced PME2. Upon pro-inflammatory stimulation, both cell types secreted PGE2. Changes in endocannabinoid levels and expression of endocannabinoid-related genes were observed in HFLS-OA following stimulation. miRNA sequencing revealed significant differences in miRNA expression between HFLS and HFLS-OA. Notably, HFLS-OA exhibited upregulation of Diacylglycerol lipase B (DAGLB) and downregulation of Fatty Acid-Binding Protein 4 and 5 (FABP4 and FABP5) gene expression compared to controls. The study suggests a reorganization of the endocannabinoid system in HFLS from OA patients, leading to altered cellular responses to pro-inflammatory stimuli. The molecular changes observed may drive or regulate the inflammatory response in OA synoviocytes, highlighting potential therapeutic targets. These findings provide insights into the potential mechanisms underlying OA pathogenesis and support the hypothesis of altered endocannabinoid system reactivity in HFLS in the context of inflammation.

The Elusive Truth of Cannabinoids for Rheumatic Pain

PURPOSE OF REVIEW

Medical cannabis (MC) has entered mainstream medicine by a unique route. Regulatory acceptance as a medical product in many jurisdictions has bypassed the traditional evidence-based pathway required for therapies. Easier access to MC, especially related to recreational legalization of cannabis, has led to widespread use by patients for symptom relief of a variety of medical conditions and often without medical oversight. Musculoskeletal pain remains the most common reason for MC use. This review examines real-world issues pertaining to MC and offers some guidance for clinical care of patients with rheumatic diseases being treated with MC.

RECENT FINDINGS

Controlled clinical studies of cannabis products in patients with rheumatic diseases have been small and tested a range of compounds, routes of administration, and clinical populations, limiting our ability to generate conclusions on MC's effectiveness in this population. Observational cohort studies and surveys suggest that use of MC and related products in patients with rheumatic diseases improves pain and associated symptoms but is commonly accompanied by mild to moderate side effects. Conflicting evidence contributes to practitioner and patient uncertainty regarding the use of MC for rheumatic disease-related pain. Despite promising preclinical and observational evidence that MC and cannabis-derived compounds are useful in the management of rheumatic disease-related pain, there remains limited high-quality clinical evidence to substantiate these findings. There are a significant number of clinical trials on this topic currently planned or underway, however, suggesting the next decade may yield more clarity. Nevertheless, given that many people with rheumatic diseases are using cannabis products, healthcare professionals must remain apprised of the evidence pertaining to cannabinoids, communicate such evidence to patients in a meaningful way that is free from personal bias and stigma, and maintain strong collaborative clinical care pertaining to MC.

Evidence for the use of cannabis-based medicines in osteoarthritis: a scoping review

The purpose of this study was to conduct a scoping review to describe the evidence on the efficacy and safety of using cannabis-based medicines for osteoarthritis. The review was conducted following the framework proposed by Arksey and O'Malley and reported following PRISMA extension for scoping reviews guidelines. We conducted a comprehensive search across various databases including MEDLINE, Embase, Cochrane Library, CINAHL, Scopus, and Proquest, spanning from inception of each database to March 2023. We retrieved 2533 citations, and after deduplication, title and abstract screening, and full-text screening, 10 articles were included for analysis. These studies were composed of randomized-controlled trials (n = 4/10), cross-sectional surveys (n = 3/10), case studies (n = 2/10), and a cohort study (n = 1/10). Evidence for using cannabis-based medicines was mixed, with just 60% (n = 6/10) of included studies reporting statistically significant improvements in pain. Studies with larger samples sizes and longer durations of exposure did not find significant benefits for pain. The few adverse effects reported were generally mild and affected a minority of participants. Several studies also discovered that cannabis-based medicines were associated with a reduction in opioid use. Currently available data on the use of cannabis-based medicines in osteoarthritis is insufficient to make recommendations. Future research should address concerns regarding small sample sizes and short treatment durations to provide a more robust evidence base. Key Points • Current evidence remains mixed; studies that found a positive benefit with using cannabis-based medicines had limitations with small sample sizes and short durations of exposure • The use of cannabis-based medicines in osteoarthritis appears to be generally well tolerated, adverse effects are mild and experienced by a minority of participants • Cannabis-based medicines may decrease the use of opioids in patients with osteoarthritis • Future research should address the gaps in long-term efficacy and safety data.

Significant use of non-evidence-based therapeutics in a cohort of Australian fibromyalgia patients

BACKGROUND

Fibromyalgia is a common condition characterised by chronic widespread musculoskeletal pain and central sensitivity features. Appropriate management requires a multidisciplinary approach prioritising non-pharmacological strategies. Evidence-based fibromyalgia medications are not always easily available, effective or tolerated.

AIM

To characterise actual medication usage in Australian fibromyalgia patients.

METHODS

Demographic and clinical data, including medication use information, were gathered by chart review from patients attending the Monash Fibromyalgia Clinic between January 2019 and June 2022. Eligible patients were invited to complete an anonymous questionnaire between June and August 2022 to assess current therapeutic use. The questionnaire assessed fibromyalgia clinical features by using the Revised Fibromyalgia Impact Questionnaire and the 2016 modified American College of Rheumatology Fibromyalgia criteria.

RESULTS

The chart review included 474 patients, and 108 participants completed the questionnaire. Most chart review (78.7%) and questionnaire participants (85.2%) reported using at least one medication for their fibromyalgia. 48.5% of chart review patients and 58.3% of questionnaire participants reported using at least one evidence-based medication, usually amitriptyline, duloxetine or pregabalin. However, the most common individual medications for questionnaire participants were non-steroidal anti-inflammatory drugs (48.2%), paracetamol (59.3%) and opioids (34.3%), with most opioids being typical opioids. Among questionnaire participants, 14.8% reported using cannabinoids, and 70.4% reported using at least one supplement, vitamin or herbal/naturopathic preparation. Not all medication or substance use was recorded during clinic appointments.

CONCLUSION

Fibromyalgia patients engage in various pharmacotherapeutic strategies that are not always evidence-based or disclosed to their treating clinicians.

Inflammatory rheumatic diseases and the risk of drug use disorders: a register-based cohort study in Sweden

To investigate the association between chronic inflammatory rheumatic diseases (CIRD) and drug use disorder (DUD). Individuals aged ≥ 30 years in 2009 that met the following conditions were included: residing in the Skåne region, Sweden, with at least one healthcare contact in person and no history of DUD (ICD-10 codes F11-F16, F18-F19) during 1998-2009 (N = 649,891). CIRD was defined as the presence of rheumatoid arthritis (RA), ankylosing spondylitis (AS), psoriatic arthritis (PsA), or systemic lupus erythematosus. Treating CIRD as a time-varying exposure, we followed people from January 1, 2010 until a diagnosis of DUD, death, relocation outside the region, or December 31, 2019, whichever occurred first. We used flexible parametric survival models adjusted for attained age, sociodemographic characteristics, and coexisting conditions for data analysis. There were 64 (95% CI 62-66) and 104 (88-123) incident DUD per 100,000 person-years among those without and with CIRD, respectively. CIRD was associated with an increased risk of DUD in age-adjusted analysis (hazard ratio [HR] 1.77, 95% CI 1.49-2.09). Almost identical HR (1.71, 95% CI 1.45-2.03) was estimated after adjustment for sociodemographic characteristics, and it slightly attenuated when coexisting conditions were additionally accounted for (1.47, 95% CI 1.24-1.74). Fully adjusted HRs were 1.49 (1.21-1.85) for RA, 2.00 (1.38-2.90) for AS, and 1.58 (1.16-2.16) for PsA. More stringent definitions of CIRD didn't alter our findings. CIRD was associated with an increased risk of DUD independent of sociodemographic factors and coexisting conditions. Key Points • A register-based cohort study including 649,891 individuals aged≥30 residing in the Skåne region, Sweden, was conducted. • Chronic inflammatory rheumatic diseases were associated with higher risks of drug use disorder independent of sociodemographic factors and coexisting conditions.

Supporting Machine Learning Model in the Treatment of Chronic Pain

Conventional therapy options for chronic pain are still insufficient and patients most frequently request alternative medical treatments, such as medical cannabis. Although clinical evidence supports the use of cannabis for pain, very little is known about the efficacy, dosage, administration methods, or side effects of widely used and accessible cannabis products. A possible solution could be given by pharmacogenetics, with the identification of several polymorphic genes that may play a role in the pharmacodynamics and pharmacokinetics of cannabis. Based on these findings, data from patients treated with cannabis and genotyped for several candidate polymorphic genes (single-nucleotide polymorphism: SNP) were collected, integrated, and analyzed through a machine learning (ML) model to demonstrate that the reduction in pain intensity is closely related to gene polymorphisms. Starting from the patient's data collected, the method supports the therapeutic process, avoiding ineffective results or the occurrence of side effects. Our findings suggest that ML prediction has the potential to positively influence clinical pharmacogenomics and facilitate the translation of a patient's genomic profile into useful therapeutic knowledge.

Medical Cannabis in Hand Surgery: A Review of the Current Evidence

Acute and chronic pain management remains an ongoing challenge for hand surgeons. This has been compounded by the ongoing opioid epidemic in the United States. With the increasing legalization of medical and recreational cannabis throughout the United States and other countries, previous societal stigmas about this substance keep evolving, and recognition of medical cannabis as an opioid-sparing pain management alternative is growing. A review of the current literature demonstrates a strong interest from patients regarding the use of medical cannabis for pain control. Current evidence demonstrates its efficacy and safety for chronic musculoskeletal and neuropathic pain. However, definitive conclusions regarding the efficacy of cannabis for pain control in hand and upper extremity conditions require continued investigation. The purpose of this article is to provide a general review of the mechanism of medical cannabis and a scoping review of the current evidence for its efficacy, safety, and potential applicability in hand and upper extremity conditions.