Long-term observational studies with cannabis-based medicines for chronic non-cancer pain: A systematic review and meta-analysis of effectiveness and safety

Cannabis constituents for chronic neuropathic pain; reconciling the clinical and animal evidence

Chronic neuropathic pain is a debilitating pain syndrome caused by damage to the nervous system that is poorly served by current medications. Given these problems, clinical studies have pursued extracts of the plant Cannabis sativa as alternative treatments for this condition. The vast majority of these studies have examined cannabinoids which contain the psychoactive constituent delta-9-tetrahydrocannabinol (THC). While there have been some positive findings, meta-analyses of this clinical work indicates that this effectiveness is limited and hampered by side-effects. This review focuses on how recent preclinical studies have predicted the clinical limitations of THC-containing cannabis extracts, and importantly, point to how they might be improved. This work highlights the importance of targeting channels and receptors other than cannabinoid CB1 receptors which mediate many of the side-effects of cannabis.

Clinical Benefits and Safety of Medical Cannabis Products: A Narrative Review on Natural Extracts

Interest in medical cannabis and cannabis-based medicinal products (CBMPs) has increased greatly in recent years. Two cannabinoids are of principal importance; delta-9-tetrahydrocannabinol (∆9-THC), the primary psychoactive component, and also cannabidiol (CBD), considered non-intoxicating. Each has distinct mechanisms of action and different therapeutic potentials. CBMPs differ in their ∆9-THC and CBD components; predominantly ∆9-THC, balanced formulations with equivalent ∆9-THC and CBD elements, and CBD-predominant products. In this narrative review, we evaluate the published evidence for the clinical benefits of CBMPs and overall benefits in well-being. We also review the overall safety profile and discuss the potential for dependence with CBMPs. Evidence can be drawn from a wide range of randomized and other controlled studies and from observational real-world studies. Most data from observational registry studies are supportive of ∆9-THC-based products (∆9-THC-predominant or balanced CBMPs) in the management of chronic neuropathic pain. Balanced products are also effective in reducing spasticity in multiple sclerosis. Most CBMPs show benefit in providing symptomatic benefits in reducing anxiety, nausea, and in improving sleep, but the place of specific products is more subtle, and choice guided by specific circumstances. Symptomatic improvements are accompanied by improved quality of life and well-being. Safety data indicate that CBMPs are generally well tolerated in most patients without specific contraindications. The majority of adverse effects are non-serious, and transient; most are principally associated with ∆9-THC and are dose-dependent. In contrast to recreational cannabis use, there is little evidence from clinical studies that CBMPs have any potential for dependence.

Patient out-of-pocket costs for cannabis use during cancer treatment

BACKGROUND

We assessed patient costs associated with cannabis use during cancer treatment.

METHODS

Adults treated for cancer at a large, comprehensive center completed an anonymous survey regarding their thoughts and experiences with cannabis and cancer. Bivariate and weighted multivariable logistic regression assessed clinical and sociodemographic factors associated with patient-reported out-of-pocket costs for cannabis products.

RESULTS

Overall, 248 cannabis users provided data on cost and were analyzed. Median monthly out-of-pocket cost for cannabis was $80 (interquartile range = $25-$150). On regression analysis, male gender (odds ratio = 2.5, 95% confidence interval = 1.2 to 5.5, P = .026) and being 45 years of age or older (odds ratio = 7.5, 95% confidence interval = 1.9 to 30.0, P = .0042) were associated with spending $100 a month or more on cannabis. Of the 166 patients who stopped using cannabis early or used less than preferred, 28% attributed it to cost and 26% to lack of insurance coverage.

CONCLUSION

Cannabis use during cancer treatment may contribute to significant out-of-pocket costs, with men and younger patients more likely to pay higher costs.

[Benefits and harms of cannabis-based medicines from the viewpoint of patients with chronic pain and their physicians : A cohort study in three pain centers of the German federal state Saarland]

BACKGROUND

There are no studies available that have simultaneously assessed the benefits and harms of cannabis-based medicines from the viewpoint of patients and their physicians.

METHODS

All chronic pain patients at three pain centres in the German federal state of Saarland who had received at least one prescription of cannabis-based medicines (CbMs) in the past from the study centre were included in a cross-sectional study from January 1 to December 31, 2021. Patients and their physicians completed a self-developed questionnaire separately.

RESULTS

All 187 contacted patients participated in the study. Since the start of CbM therapy, 44.9% of patients reported to be much or very much, 43.3% to be moderately and 8.0% to be slightly improved overall. A total of 2.7% reported no change and 1.1% a moderate deterioration of overall wellbeing. From the patients' point of view, the symptoms most frequently reported to have substantially improved were sleep problems (36.4%), muscle tension (25.1%) and appetite problems (22.1%). The most frequent bothersome side effects were sweating (6.4%), concentration problems (4.2%) and nausea (4.1%). Physicians noted substantial pain relief in 60.7%, improvement of sleep in 65.7% and of mental well-being in 34.3%. A complete cessation of opioids was achieved in 64.7%, of anticonvulsants in 57.9% and of antidepressants in 60% of patients that had received these medications before the start of CbM therapy.

CONCLUSIONS

CbMs can contribute to a clinically relevant reduction in pain, sleep problems and muscle tension and can improve daily functioning in carefully selected and supervised patients with chronic pain. CbM can contribute to the reduction or complete cessation of other pain medications (antidepressants, anticonvulsants, opioids).

[Patient-reported outcomes in chronic diseases under treatment with cannabis medicines : Analysis of the results of the Copeia survey]

BACKGROUND

The survey of Copeia captured early 2022 patient-reported outcomes (PRO) in Germany under cannabis medicinal product (CAM) therapy, with particular attention to symptoms, symptom changes, indications, side effects, dosages, and cost bearers.

GOAL

This study investigated the question of whether associations emerge from the results that could play a role in the indication and treatment monitoring of CAM in chronically ill patients.

MATERIALS AND METHODS

A standardized questionnaire was administered online nationwide in dialogue form over a 15-week period to collect itemized symptoms and PRO. Recruitment was supported by pharmacies, prescribing physicians, and patient associations. Inclusion criteria included physician-prescribed CAM therapy.

RESULTS AND DISCUSSION

Of 1582 participants, 1030 data sets (65%) could be completely analyzed. There was a heterogeneous patient population, whose common feature was disease chronicity. The frequency distribution of symptoms showed a homogeneous pattern for the respective indications, in which the most frequent six (pain 71%, sleep disturbance 64%, stress/tension 52%, inner restlessness 52%, depressive mood 44% and muscle tension 43%) seem to have a special significance. According to subjective assessment, quality of life improved significantly in 84% of all participating patients.

CONCLUSION

A symptom matrix (SMX) composed of different symptoms seems to play a special role in CAM therapy to improve the quality of life of chronically ill patients, regardless of the underlying disease. The SMX could contribute to the identification of an indication and to targeted treatment monitoring.

Suicidal Ideation in Medicinal Cannabis Patients: A 12-Month Prospective Study

OBJECTIVE

To document the prevalence and correlates of suicidal ideation (SI) among individuals seeking cannabis-based medicinal products (CBMPs); to test whether SI declines or intensifies after three months of CBMP treatment and to document 12-month trajectories of depression in those reporting SI and other patients.

METHOD

Observational data were available for 3781 patients at entry to treatment, 2112 at three months and 777 for 12 months. Self-reported depressed mood and SI were assessed using items from the PHQ-9. Additional data included sociodemographic characteristics and self-reported well-being.

RESULTS

25% of the sample reported SI at treatment entry and those with SI had higher levels of depressed mood (mean = 17.4 vs. 11.3; F(1,3533) = 716.5, p < .001) and disturbed sleep (mean = 13.8 vs. 12.2, F(1,3533) = 125.9, p < .001), poorer general health (mean = 43.6 vs. 52.2, F(1,3533) = 118.3, p < .001) and lower quality of life (mean = 0.44 vs. 0.56 (F(1,3533) = 118.3, p < .001). The prevalence of SI reduced from 23.6% to 17.6% (z = 6.5, p < .001) at 3 months. Twelve-month follow-up indicated a substantial reduction in depressed mood with this reduction being more pronounced in those reporting SI (mean (baseline) = 17.7 vs. mean (12 months) = 10.3) than in other patients (mean (baseline) = 11.1 vs. mean (12 months) = 7.0).

CONCLUSIONS

SI is common among individuals seeking CBMPs to treat a range of chronic conditions and is associated with higher levels of depressed mood and poorer quality of life. Treatment with CBMPs reduced the prevalence and intensity of suicidal ideation.

The Use of Compounds Derived from Cannabis sativa in the Treatment of Epilepsy, Painful Conditions, and Neuropsychiatric and Neurodegenerative Disorders

Neurological disorders present a wide range of symptoms and challenges in diagnosis and treatment. Cannabis sativa, with its diverse chemical composition, offers potential therapeutic benefits due to its anticonvulsive, analgesic, anti-inflammatory, and neuroprotective properties. Beyond cannabinoids, cannabis contains terpenes and polyphenols, which synergistically enhance its pharmacological effects. Various administration routes, including vaporization, oral ingestion, sublingual, and rectal, provide flexibility in treatment delivery. This review shows the therapeutic efficacy of cannabis in managing neurological disorders such as epilepsy, neurodegenerative diseases, neurodevelopmental disorders, psychiatric disorders, and painful pathologies. Drawing from surveys, patient studies, and clinical trials, it highlights the potential of cannabis in alleviating symptoms, slowing disease progression, and improving overall quality of life for patients. Understanding the diverse therapeutic mechanisms of cannabis can open up possibilities for using this plant for individual patient needs.

Overview: Chronic Pain and Cannabis-Based Medicines

Chronic pain is primarily conceptualized as a disease in its own right when it is associated with emotional distress and functional impairment. Pathophysiologically, dysfunction of the cortico-mesolimbic connectome is of major importance, with overlapping signals in the nociceptive and stress systems. The endocannabinoid system plays an important role in the central processing of nociceptive signals and regulates the central stress response. Clinically, there is moderate evidence that cannabis-based medicines (CBM) can contribute to a significant reduction in pain, especially the associated pain affect, and improvement in physical function and sleep quality in a proportion of patients with chronic pain. The analgesic effect appears to be largely independent of the cause of pain. In this context, CBM preferentially regulates stress-associated pain processing.

Cannabis medicine for chronic pain

In the last decade, patients with chronic pain have expressed increasing interest in cannabis-derived products for adjuvant therapy when treatment is deemed refractory to conventional analgesics. At present, clinical evidence to support this treatment approach appears to be sparse. Not because clinical studies as such are lacking, but rather as a result of methodological bias in relation to study design, patient populations, and treatment protocols. In this review, research in cannabis medicine for relief of chronic pain is reviewed, mainly with reference to published meta-analytic studies.

Cannabis oil extracts for chronic pain: what else can be learned from another structured prospective cohort?

Introduction

The use of medicinal cannabis for managing pain expands, although its efficacy and safety have not been fully established through randomized controlled trials.

Objectives

This structured, prospective questionnaire-based cohort was aimed to assess long-term effectiveness and safety of cannabis oil extracts in patients with chronic pain.

Methods

Adult Israeli patients licensed to use cannabis oil extracts for chronic pain were followed prospectively for 6 months. The primary outcome measure was change from baseline in average weekly pain intensity, and secondary outcomes were changes in related symptoms and quality of life, recorded before treatment initiation and 1, 3, and 6 months thereafter. Generalized linear mixed model was used to analyze changes over time. In addition, "responders" (≥30% reduction in weekly pain at any time point) were identified.

Results

The study included 218 patients at baseline, and 188, 154, and 131 at 1, 3, and 6 months, respectively. At 6 months, the mean daily doses of cannabidiol and Δ9-tetrahydrocannabinol were 22.4 ± 24.0 mg and 20.8 ± 30.1 mg, respectively. Pain decreased from 7.9 ± 1.7 at baseline to 6.6 ± 2.2 at 6 months (F(3,450) = 26.22, P < 0.0001). Most secondary parameters also significantly improved. Of the 218 participants, 24% were "responders" but could not be identified by baseline parameters. "Responders" exhibited higher improvement in secondary outcomes. Adverse events were common but mostly nonserious.

Conclusion

This prospective cohort demonstrated a modest overall long-term improvement in chronic pain and related symptoms and a reasonable safety profile with the use of relatively low doses of individually titrated Δ9-tetrahydrocannabinol and cannabidiol.

Natural Products Derived from Cannabis sativa for Pain Management

Cannabis sativa is one of the oldest medicinal plants in human history. Even ancient physicians from hundreds of years ago used Cannabis sativa to treat several conditions like pain. In the modern era, the research community, including health-care providers, have witnessed wide-scale changes in cannabis policy, legislation, and marketing, with a parallel increase in patient interest. A simple search in PubMed using "cannabis and pain" as keywords provides more than 2,400 articles, about 80% of which were published in the last 8-10 years. Several advancements have been achieved in understanding the complex chemistry of cannabis along with its multiple pharmacological activities. Preclinical data have demonstrated evidence for the promising potential of cannabis for pain management, and the continuous rise in the prevalence of pain increases the urgency to translate this into clinical practice. Despite the large body of cannabis literature, researchers still need to find rigorous answers for the questions about the efficacy and safety of cannabis in treatment of certain disorders such as pain. In the current chapter, we seek to present a critical overview about the current knowledge on cannabis with special emphasis on pain-related disorders.

Therapeutic use of medical Cannabis in neurological diseases: a clinical update

The use of medical Cannabis has increased in recent years due to changing legal circumstances in many countries. Approval exists only for a few neurological conditions such as rare forms of epilepsy or spasticity in multiple sclerosis. Beyond that, however, medical Cannabis is used for a wide range of neurological conditions and symptoms. In Germany, in parallel with new legislation that has simplified the prescription of medical Cannabis, an accompanying survey has been implemented for which initial data are now available. In this context, our review provides an overview of the evidence for the therapeutic use of medical Cannabis in neurology, the potential benefits, and side effects.

An observational study of pain severity, cannabis use, and benefit expenditures in work disability

OBJECTIVE

This study pools two cohorts of workers in Ontario interviewed 18 months following a disabling work-related injury to estimate the association between pain severity, cannabis use, and disability benefit expenditures.

METHODS

Among 1650 workers, disability benefit expenditures obtained from administrative records were combined with self-reported measures of pain symptoms and cannabis use. Disability benefit expenditures comprised wage replacement benefits and expenditures on healthcare services.

RESULTS

Past-year cannabis use was reported by 31% of participants, with approximately one third of cannabis use attributed to the treatment of conditions arising from the work-related injury. Condition-related cannabis use was elevated among the 34% of participants reporting severe pain symptoms. In regression models adjusted for age, sex, nature of injury, opioid prescription, and pre-injury chronic conditions, participants reporting condition-related cannabis use had equivalent wage replacement benefit expenditures (β = 0.254, ns) and higher healthcare benefit expenditures (β = 0.433, p = 0.012) compared to participants who did not use cannabis. Participants reporting cannabis use unrelated to conditions arising from their work-related injury had lower wage replacement benefit expenditures (β =  - 0.309, p = 0.002) and equivalent healthcare benefit expenditures (β =  - 0.251, ns) compared to participants not using cannabis.

CONCLUSION

This novel study of workers' compensation claimants interviewed at 18 months post-injury did not observe a substantial relationship between cannabis use and disability benefit expenditures, suggesting that neither harm nor significant benefit is associated with cannabis use. These findings contribute to understanding the potential benefits and risks associated with cannabis use in settings that have legalized cannabis use.

A Descriptive Analysis of Adverse Event Reports from the Quebec Cannabis Registry

INTRODUCTION

Published data on the safety of natural medical cannabis (MC) when used in the real-world clinical practice setting are lacking. This study aimed to describe adverse events (AEs) reported across three years following MC initiation.

METHODS

The Quebec Cannabis Registry (QCR) was a prospective registry of adults enrolled through participating physicians when they initiated MC between May 2015 and October 2018. Follow-up ended at MC discontinuation, loss to follow-up, three years, or end of data collection (May 2019). Data were collected at baseline and at follow-up visits every three months for the first two years, then once in the third year. Physicians filled adverse event (AE) reports, which were coded using MedDRA® preferred terms (PTs), and descriptive analyses were conducted.

RESULTS

A total of 2991 patients were enrolled (mean age 50.9 years, 50.2% females). During follow-up, 108 patients (3.6%) experienced moderate or severe AEs, yielding 111 AE reports (three patients had two reports) and 214 AEs (average 1.9 AEs per report). Mild AEs were recorded as a reason for MC discontinuation for nine patients, but no AE reports were available. The most common PTs for ingested MC (62 reports) were dizziness (12.9%), nausea (11.3%), somnolence (9.7%), and vomiting (8.1%), and for inhaled MC (23 reports), headache (13.0%) was the most common. The most frequent PTs associated with tetrahydrocannabinol (THC)-dominant MC (25 reports) were dizziness and somnolence (12.0% each); for cannabidiol (CBD)-dominant MC (20 reports), vomiting (20.0%) was most common; and dizziness (17.2%), nausea (13.8%), somnolence (10.3%), and headache (8.6%) were the most frequent for balanced MC (58 reports).

CONCLUSION

No new safety concerns were identified relative to the published literature, although notable differences in AE profile between modes of administration and cannabinoid content ratios should be considered by health professionals. Further work identifying and managing risk factors for AEs is warranted to maintain a favorable benefit-risk balance for MC.

Medical Cannabis Prescription Practices and Quality of Life in Thai Patients: A Nationwide Prospective Observational Cohort Study

Introduction

The legalization of cannabis in Thailand has renewed interest in its traditional medical use. This study aimed to explore the prescribing patterns of traditional practitioners and assess the impact of cannabis oil on patients' quality of life, with a specific focus on comparing outcomes between cancer and non-cancer patients.

Methods

We conducted a prospective observational cohort study across 30 sites in 21 Thai provinces to analyze the use of "Ganja Oil," a cannabis extract in 10% coconut oil, prescribed for symptoms like pain, anorexia, and insomnia across a diverse patient group, including cancer and migraines. Quality of life was assessed using the Edmonton Symptom Assessment Scale (ESAS) and EQ-5D-5L at baseline, 1, 2, and 3 months. The study included a predefined subgroup analysis to compare the effects on cancer versus non-cancer patients. Data management was facilitated through Research Electronic Data Capture (REDCap), with statistical analysis performed using Stata/MP.

Results

Among 21,284 participants, the mean age was 54.10 ± 15.32 years, with 52.49% being male. The baseline EQ-5D-5L index was 0.85 ± 0.24. Significant differences in EQ-5D-5L indices were seen between cancer patients (0.79 ± 0.32) and non-cancer patients (0.85 ± 0.23; p < 0.001). ESAS scores also differed significantly between these groups for all symptoms, except anxiety. The most frequent prescription of Ganja Oil was oral administration at bedtime (88.26%), with the predominant dosage being three drops daily, approximately 0.204 mg of tetrahydrocannabinol in total. Posttreatment, significant improvements were noted: the EQ-5D-5L index increased by 0.11 points (95% CI: 0.11, 0.11; p < 0.001) overall, 0.13 points (95% CI: 0.12, 0.14; p < 0.001) for cancer patients, and 0.11 points (95% CI: 0.10, 0.11; p < 0.001) for non-cancer patients. ESAS pain scores improved by -2.66 points (95% CI: -2.71, -2.61; p < 0.001) overall, -2.01 points (95% CI: -2.16, -1.87; p < 0.001) for cancer patients, and -2.75 points (95% CI: -2.80, -2.70; p < 0.001) for non-cancer patients, with similar significant improvements in other symptoms.

Conclusion

Our study indicates potential benefits of Ganja Oil for improving quality of life among Thai patients, as a complementary treatment. These findings must be viewed in light of the study's design limitations. Further controlled studies are essential to ascertain its efficacy and inform dosing guidelines.

Drug Interactions of Tetrahydrocannabinol and Cannabidiol in Cannabinoid Drugs

BACKGROUND

Cannabinoid drugs containing tetrahydrocannabinol (THC), or its structural analogues, as monotherapeutic agents or as extracts or botanical preparations with or without cannabidiol (CBD) are often prescribed to multimorbid patients who are taking multiple drugs. This raises the question of the risk of drug interactions.

METHODS

This review of the pharmacokinetics and pharmacodynamics of interactions with cannabinoid drugs and their potential effects is based on pertinent publications retrieved by a selective literature search.

RESULTS

As THC and CBD are largely metabolized in the liver, their bioavailability after oral or oral-mucosal administration is low (6-8% and 11-13%, respectively). The plasma concentrations of THC and its active metabolite 11-OH-THC can be increased by strong CYP3A4 inhibitors (verapamil, clarithromycin) and decreased by strong CYP3A4 inductors (rifampicin, carbamazepine). The clinical significance of these effects is unclear because of the variable plasma level and therapeutic spectrum of THC. The metabolism of CBD is less dependent on cytochrome P450 enzymes than that of THC. THC and CBD inhibit CYP2C and CYP3A4; the corresponding clinically relevant drug interactions probably are likely to arise only with THC doses above 30 mg/day and CBD doses above 300 mg/day.

CONCLUSION

Potential drug interactions with THC and CBD are probably of little importance at low or moderate doses. Strong CYP inhibitors or inductors can intensify or weaken their effect. Slowly ramping up the dose of oral cannabinoid drugs can lessen their pharmacodynamic interactions, which can generally be well controlled. Administration by inhalation can worsen the interactions.

Medical Cannabis Is Not Associated with a Decrease in Activities of Daily Living in Older Adults

The proportion of older adults using medical cannabis is rising. Therefore, we aimed to assess the effects of herbal medical cannabis on the functional status of older adults. We conducted a prospective observational study of patients aged 65 years or older that initiated cannabis treatment for different indications, mostly chronic non-cancer pain, during 2018-2020 in a specialized geriatric clinic. The outcomes assessed were activities of daily living (ADL), instrumental activities of daily living (IADL), pain intensity, geriatric depression scale, chronic medication use, and adverse events at six months. A cohort of 119 patients began cannabis treatment: the mean age was 79.3 ± 8.5 and 74 (62.2%) were female. Of the cohort, 43 (36.1%) experienced adverse effects due to cannabis use and 2 (1.7%) required medical attention. The mean ADL scores before and after treatment were 4.4 ± 1.8 and 4.5 ± 1.8, respectively (p = 0.27), and the mean IADL scores before and after treatment were 4.1 ± 2.6 and 4.7 ± 3, respectively (p = 0.02). We concluded that medical cannabis in older adults has a number of serious adverse events, but was not associated with a decrease in functional status, as illustrated by ADL and IADL scores after six months of continuous treatment.

What Do We Know about Nociplastic Pain?

Nociplastic pain is a recently distinguished type of pain, distinct from neuropathic and nociceptive pain, and is well described in the literature. It is often mistaken for central sensitization. Pathophysiology has not been clearly established with regard to alteration of the concentration of spinal fluid elements, the structure of the white and gray matter of the brain, and psychological aspects. Many different diagnostic tools, i.e., the painDETECT and Douleur Neuropathique 4 questionnaires, have been developed to diagnose neuropathic pain, but they can also be applied for nociplastic pain; however, more standardized instruments are still needed in order to assess its occurrence and clinical presentation. Numerous studies have shown that nociplastic pain is present in many different diseases such as fibromyalgia, complex regional pain syndrome type 1, and irritable bowel syndrome. Current pharmacological and nonpharmacological treatments for nociceptive and neuropathic pain are not entirely suitable for treating nociplastic pain. There is an ongoing effort to establish the most efficient way to manage it. The significance of this field has led to several clinical trials being carried out in a short time. The aim of this narrative review was to discuss the currently available evidence on pathophysiology, associated diseases, treatment possibilities, and clinical trials. It is important that physicians widely discuss and acknowledge this relatively new concept in order to provide optimized pain control for patients.

Sleep disorders in chronic pain and its neurochemical mechanisms: a narrative review

Chronic pain (CP) is a prevalent problem, and more than half of patients with CP have sleep disorders. CP comorbidity with sleep disorders imposes immense suffering and seriously affects the patient's quality of life, which is a challenging issue encountered by clinicians. Although the reciprocal interactions between pain and sleep have been studied to some degree, there is still a lack of awareness and comprehensive description of CP comorbidity with sleep disorders. In this narrative review article, we summarize the current knowledge about the present estimates of the prevalence of comorbid sleep disorders in CP patients, sleep detection methods, sleep characterization in CP, and the effect of sleep disorders on CP and current therapies. We also summarize current knowledge of the neurochemical mechanisms of CP comorbidity with sleep disorders. In conclusion, insufficient attention has been paid to the role of sleep disorders in CP patients, and CP patients should be screened for sleep disorders in the clinic. Special attention should be given to a possible risk of drug-drug interaction when using two types of drugs targeting pain and sleep simultaneously. The current insight into the neurobiological mechanisms underlying CP comorbidity with sleep disorders is still rather limited.

[Complementary and alternative medicine-An option for chronic pain patients?]

The interest of patients with chronic pain in complementary and alternative medicine (CAM) is high. The aim of an accompanying complementary therapy is to strengthen the patient's self-efficacy, the ability to make decisions and the autonomy. The best evidence exists for physical activity and a balanced diet. Exercise combinations of strength and endurance as well as targeted strengthening of the muscles in the area of the pain are particularly suitable. When choosing the form of exercise, low-threshold training options are recommended. There is no reliable evidence for kinesio taping, homeopathy, neural therapy and draining procedures. The extensive data on acupuncture must be interpreted taking methodological limitations into account. Heat applications can support multimodal pain therapy. In the case of anti-inflammatory phytotherapeutic agents, there are good rationales from basic research and reliable empirical knowledge regarding the dosage. The evidence on cannabis is low.

Influence of Cannabinoid Treatment on Trajectories of Patient-Related Outcomes in Chronic Pain: Pain Intensity, Emotional Distress, Tolerability and Physical Disability

The treatment of chronic pain with cannabinoids is becoming more widespread and popular among patients. However, studies show that only a few patients experience any benefit from this treatment. It also remains unclear which domains are affected by cannabinoid treatment. Therefore, the present study is novel in that it explores the effects of cannabinoid treatment on four patient-related outcome measures (PROMs), and includes patients with chronic refractory pain conditions who have been given the option of cannabinoid treatment. A retrospective design was used to evaluate the impact of cannabinoid treatment on patients with refractory pain in two German outpatient pain clinics. The present study shows that pain intensity (mean relative reduction (-14.9 ± 22.6%), emotional distress (-9.2 ± 43.5%), pain-associated disability (-7.0 ± 46.5%) and tolerability of pain (-11 ± 23.4%)) improved with cannabinoid treatment. Interestingly, the trajectories of the PROMs seemed to differ between patients, with only 30% of patients responding with respect to pain intensity, but showing improvements in other PROMs. Although the mean treatment effects remained limited, the cumulative magnitude of change in all dimensions may affect patients' quality of life. In summary, a singular evaluation with pain intensity as the sole outcome does not cover the multidimensional effects of cannabinoids. Therefore, the treatment effects of cannabinoids should be evaluated with different PROMs.

Safety and effectiveness of cannabinoids to Danish patients with treatment refractory chronic pain-A retrospective observational real-world study

BACKGROUND

Cannabinoids are considered a therapeutic option to patients suffering from treatment refractory chronic pain (TRCP) insufficiently relieved by conventional analgesics or experiencing intolerable adverse events (AEs) from those. This study aimed to explore safety and effectiveness of oral cannabinoids among patients with TRCP.

METHODS

A retrospective study was conducted among Danish patients with TRCP being prescribed oral cannabinoids. Data on AEs and changes in pain intensity by numeric rating scale (NRS) before and after initiation of oral cannabinoid therapy were analysed.

RESULTS

Among 826 eligible patients ≥18 years old, 529 (64%) were included for data analysis at first follow-up (F/U1) (median 56 days from baseline) and 214 (26%) for second follow-up (F/U2) (median 126 days from F/U1). Mean age was 60 ± 15.9 years and 70% were females. AEs were in general reported mild to moderate by 42% of patients at F/U1 and 34% at F/U2. AEs were mainly related to gastrointestinal (F/U1: 17% and F/U2: 13%) and nervous system disorders (F/U1: 14% and F/U2: 11%). Reduction in NRS was significantly different at both follow-up consultations compared with baseline (<0.0001). Clinically relevant pain reduction (NRS ≥30%) was reported by 17% at F/U1 and 10% of patients at F/U2 in intention-to-treat analysis whereas the figures were 32% and 45% respectively, in per-protocol analysis.

CONCLUSION

Oral cannabinoid therapy seems to be safe and mildly effective in patients with TRCP. Randomized controlled trials with focus on comparable pain characteristics in diagnostical homogenous patient subgroups are needed for further improvement of evidence level for relief of chronic pain using oral cannabinoids.

SIGNIFICANCE

The findings in this retrospective study conducted in a real-world clinical setting suggest a favourable safety profile of cannabinoids. Moreover, one-sixth (intention-to-treat) and one-third (per-protocol) of patients with chronic pain refractory to conventional analgesics, or experiencing intolerable adverse effects, benefited significantly from therapy with oral cannabinoid regimens. Combination of THC and CBD seems overall more effective than cannabinoid monotherapy. Conduction of randomized controlled trials investigating safety and efficacy of cannabinoid therapy to diagnosis specific patient subgroups with comparable clinical and pathophysiological chronic pain characteristics is warranted, hence contributing further to the process of clinical evidence clarification currently in progress.

Systematic Review and Meta-analysis Seem to Indicate that Cannabinoids for Chronic Primary Pain Treatment Have Limited Benefit

INTRODUCTION

The IASP ICD-11 chronic primary pain (CPP) definition includes 19 different painful conditions. In recent years, interest in the potential role of cannabinoids in the management of CPP has increased, since they demonstrated a possible efficacy in treating pain, especially in secondary pain conditions. However, limited evidence is available for patients with CPP. The aim of this systematic review and meta-analysis is to evaluate the efficacy and safety of cannabinoid administration in CPP.

METHODS

PubMed, EMBASE, and Cochrane Library were searched form the beginning up to 31 October 2021 to retrieve published articles of randomized controlled trials (RCTs) or observational, retrospective or prospective, studies, investigating cannabinoids in CPP. The study screening process was completed during November 2021. The primary outcome was pain reduction by means of the visual analogue scale (VAS). Secondary outcomes were quality of life by means of the fibromyalgia impact questionnaire (FIQ) or other available scales, appetite, anxiety, depression, and sleep by means of any available scales. Safety was assessed with the reporting of serious adverse events (SAE) and discontinuation due to adverse events. Risk of bias was assessed. The weighted generic inverse variance method and Mantel-Haenszel method were used to estimate the mean difference (MD) and odds ratios (OR) with 95% confidence intervals (CI) for continuous and dichotomous outcomes, respectively. For outcome measures reported with different scales (pain, anxiety, depression), we used the standardized MD (SMD) as the effect measure and then converted it into units of the VAS scale for pain, the Beck Anxiety Inventory (BAI) for anxiety, and the Beck Depression Inventory (BDI) for depression. Summary of findings was produced using GRADEproGDT.

RESULTS

From 3007 identified records, we included eight articles reporting the results of eight different RCTs (four parallel and four crossover studies; seven compared to placebo and one to amitriptyline), with a total population of 240 patients. VAS pain reduction was non-significant for cannabinoids against placebo (MD = - 0.64; 95% CI - 1.30 to 0.02) or amitriptyline (MD = - 0.19; 95% CI - 0.58 to 0.19). More than 4 weeks cannabinoid treatment significantly reduced pain compared to placebo in parallel studies with more than 4 weeks of treatment duration (MD = - 1.28; 95% CI - 2.33 to - 0.22). Differences for the FIQ (MD = - 21.69; 95% CI - 46.20 to 2.82), BAI (MD = - 2.32; 95% CI - 7.99 to 3.08), and BDI (MD = 2.32; 95% CI - 1.71 to 6.35) were non-significant, likewise for discontinuation due to adverse events (OR = 2.15; 95% CI 0.44-10.65), when comparing cannabinoids to placebo. The quality of the evidence was generally low mainly as a result of imprecision and risk of bias.

CONCLUSION

Cannabinoid treatment in patients with CPP had limited benefit on pain relief; however, it might improve pain with long-term administration.