The Effect of Medicinal Cannabis on Pain and Quality-of-Life Outcomes in Chronic Pain: A Prospective Open-label Study

Changes in health-related quality of life over the first three months of medical marijuana use

BACKGROUND

The psychosocial impact of medical marijuana use is not yet known. This study evaluated short-term changes in health-related quality of life (HRQoL) over the first three months of medical marijuana use.

METHODS

This prospective, observational, longitudinal study followed adults newly recommended for medical marijuana by a physician for any of the more than 20 qualifying medical conditions in Pennsylvania. Participants (N = 438) provided their clinical status and demographic information, and completed semi-structured interviews prior to medical marijuana initiation (baseline) and at three months. HRQoL was assessed by the Short Form-36 (SF-36). Paired-samples t-tests evaluated changes in HRQoL over time.

RESULTS

Participants (M age = 46.4 years [15.6]; 66.4% female) were mostly commonly referred for medical marijuana to treat anxiety disorders (61.9%) or severe chronic or intractable pain (53.6%). Participants reported rapid and significant improvements in all of the domains of HRQoL from baseline to three months after initiating medical marijuana use (physical functioning, role limitations due to physical health problems, emotional well-being, role limitations due to emotional problems, bodily pain, social functioning, energy/fatigue and general health, P < .001 for all). Age was negatively predictive of level of improvement over time for the physical functioning (P < .0001), role limitations due to physical health problems (P < .001), and pain (P < .0001) domains after controlling for baseline, with older participants displaying less improvement than younger participants.

CONCLUSIONS

Gains were observed in all HRQoL domains assessed after three months of medical marijuana use. In several domains, age was a significant predictor of degree of improvement.

Substituting Medical Cannabis for Medications Among Patients with Rheumatic Conditions in the United States and Canada

OBJECTIVE

There are numerous reports of people substituting medical cannabis (MC) for medications. Our obejctive was to investigate the degree to which this substitution occurs among people with rheumatic conditions.

METHODS

In a secondary analysis from a cross-sectional survey conducted with patient advocacy groups in the US and Canada, we investigated MC use and medication substitution among people with rheumatic conditions. We subgrouped by whether participants substituted MC for medications and investigated differences in perceived symptom changes and use patterns, including methods of ingestion, cannabinoid content (cannabidiol vs delta-9-tetrahydrocannabinol [THC]), and use frequency.

RESULTS

Among 763 participants, 62.5% reported substituting MC products for medications, including nonsteroidal anti-inflammatory drugs (54.7%), opioids (48.6%), sleep aids (29.6%), and muscle relaxants (25.2%). Following substitution, most participants reported decreases or cessation in medication use. The primary reasons for substitution were fewer adverse effects, better symptom management, and concerns about withdrawal symptoms. Substitution was associated with THC use and significantly higher symptom improvements (including pain, sleep, anxiety, and joint stiffness) than nonsubstitution, and a higher proportion of substitutors used inhalation routes than those who did not.

CONCLUSION

Although the determination of causality is limited by our cross-sectional design, these findings suggest that an appreciable number of people with rheumatic diseases substitute medications with MC for symptom management. Inhalation of MC products containing some THC was most commonly identified among those substituting, and disease characteristics did not differ by substitution status. Further study is needed to better understand the role of MC for symptom management in rheumatic conditions.

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.

Understanding the epidemiology and perceived efficacy of cannabis use in patients with chronic musculoskeletal pain

BACKGROUND

The belief that cannabis has analgesic and anti-inflammatory properties continues to attract patients with chronic musculoskeletal (MSK) pain towards its use. However, the role that cannabis will play in the management of chronic MSK pain remains to be determined. This study examined 1) the rate, patterns of use, and self-reported efficacy of cannabis use among patients with chronic MSK pain and 2) the interest and potential barriers to cannabis use among patients with chronic MSK pain not currently using cannabis.

METHODS

Self-reported cannabis use and perceived efficacy were prospectively collected from chronic MSK pain patients presenting to the Orthopaedic Clinic at the University Health Network, Toronto, Canada. The primary dependent variable was current or past use of cannabis to manage chronic MSK pain; bivariate and multivariable logistic regression were used to identify patient characteristics independently associated with this outcome. Secondary outcomes were summarized descriptively, including self-perceived efficacy among cannabis users, and interest as well as barriers to cannabis use among cannabis non-users.

RESULTS

The sample included 629 patients presenting with chronic MSK pain (mean age: 56±15.7 years; 56% female). Overall, 144 (23%) reported past or present cannabis use to manage their MSK pain, with 63.7% perceiving cannabis as very or somewhat effective and 26.6% considering it as slightly effective. The strongest predictor of cannabis use in this study population was a history of recreational cannabis use (OR 12.7, p<0.001). Among cannabis non-users (N=489), 65% expressed interest in using cannabis to manage their chronic MSK pain, but common barriers to use included lack of knowledge regarding access, use and evidence, and stigma.

CONCLUSIONS

One in five patients presenting to an orthopaedic surgeon with chronic MSK pain are using or have used cannabis with the specific intent to manage their pain, and most report it to be effective. Among non-users, two-thirds reported an interest in using cannabis to manage their MSK pain, but common barriers to use existed. Future double-blind placebo-controlled trials are required to understand if this reported efficacy is accurate, and what role, if any, cannabis may play in the management of chronic MSK pain.

Exploring Twitter chatter to assess the type and availability of cannabis-related products in Thailand

Cannabis-related tweets were collected between January and April 2022 to estimate the availability and characteristics of cannabis products advertised on Twitter amid the legalization of recreational cannabis in Thailand. The Twitter API was called using the tweepy Python library to collect cannabis-related tweets in the Thai language. A total of 185,558 unique tweets were collected over the duration of the data collection period based on 83 search terms. Twenty thousand random tweets were manually coded by four Thai native speakers to assess the volume and characteristics of tweets proposing cannabis. 72.6% of collected tweets from the 20,000 random samples were coded as relevant to the study. 54.6% of relevant tweets were advertising cannabis products, 29.8% were personal communications, and 15.6% were related to news or media content. Among the tweets that advertised cannabis products, 94.4% proposed cannabis flower, 2.4% cannabis edibles and 1.8% cannabis concentrates. Consumption of potent forms of cannabis such as cannabis edibles and concentrates increase the risk of harmful side-effects, especially in a population with limited knowledge about these products. Our findings call for additional monitoring efforts and for increasing the public awareness on potent cannabis products emerging in Thailand.

Comparing Cannabis Use Motivations and Dependence Across Regular Cannabis Users Who Have or Have Not Recently Used Psilocybin

Introduction: In Colorado, both cannabis and psilocybin are legal and becoming more commonly used. However, there is almost no research detailing the public health concerns regarding negative outcomes (e.g., dependence) of cannabis and psilocybin co-use and motives that may perpetuate these negative outcomes (e.g., coping, boredom). Methods: Using data from a larger observational study on cannabis and metabolic processes, regular cannabis users (use ≥7 times/month; n = 97, 35.1% female, 89.7% WHITE) who used psilocybin in the past 3 months (n = 34) were compared with those who had not used psilocybin in the past 3 months (n = 63) on cannabis dependence as measured by the Marijuana Dependence Scale and endorsement of 12 cannabis motives from the Comprehensive Marijuana Motives Questionnaire. Correlations between motives and dependence were also examined and compared across groups. Results: Findings revealed that individuals who had recently used psilocybin had greater cannabis dependence scores than those who had not used recently [F (1, 95) = 5.53, p = 0.02], and more strongly endorsed that their cannabis use was motivated by enjoyment [F (1, 91) = 4.31, p = 0.04], boredom [F (1, 91) = 9.10, p < 0.01], and availability [F (1, 91) = 9.46, p < 0.01]. Correlations between dependence scores and coping and boredom motives were also significantly positive for both groups (all p values <0.05) whereas positive correlations with experimentation, celebration, and availability motives were only significant for recent psilocybin users (all p values <0.05). Discussion: These results suggest there are motivational differences for cannabis use among those who co-use cannabis and psilocybin, and there may be a greater risk for harm for these individuals.

Assessment of Clinical Outcomes in Patients With Osteoarthritis: Analysis From the UK Medical Cannabis Registry

Osteoarthritis accounts for 0.6% of disability-adjusted life years globally. There is a paucity of research focused on cannabis-based medicinal products (CBMPs) for osteoarthritic chronic pain management. This study aims to assess changes in validated patient-reported outcome measures (PROMs) and CBMP clinical safety in patients with osteoarthritis. A prospective case series from the UK Medical Cannabis Registry was analyzed. Primary outcomes were changes in the Brief Pain Inventory (BPI), McGill Pain Questionnaire (MPQ2), EQ-5D-5L, Generalized Anxiety Disorder-7 (GAD-7) questionnaire, and Single-Item Sleep Quality Scale (SQS) at 1-, 3-, 6-, and 12-month follow-ups from baseline. Common Terminology Criteria for Adverse Events v.4.0 was used for adverse event (AE) analysis. Statistical significance was defined as p < 0.050. Seventy-seven patients met inclusion criteria. CBMP initiation correlated with BPI pain severity (p = 0.004), pain interference (p = 0.005), and MPQ2 (p = 0.017) improvements at all follow-ups compared to baseline. There were improvements in the EQ-5D-5L index (p = 0.026), SQS (p < 0.001), and GAD-7 (p = 0.038) up to 6 and 3 months, respectively. Seventeen participants (22.08%) recorded 76 mild AEs (34.86%), 104 moderate AEs (47.71%), and 38 severe AEs (17.43%). Though causality cannot be assumed in this observational study, results support development of randomized control trials for osteoarthritis pain management with CBMPs.

Oral Delta-9-Tetrahydrocannabinol (THC) Increases Parasympathetic Activity and Supraspinal Conditioned Pain Modulation in Chronic Neuropathic Pain Male Patients: A Crossover, Double-Blind, Placebo-Controlled Trial

BACKGROUND

Disordered autonomic nervous system regulation and supraspinal pain inhibition have been repeatedly described in chronic pain. We aimed to explore the effects of δ-9-tetrahydrocannabinol (THC), an emerging treatment option, on autonomic nervous system and central pain modulation measures in patients with chronic pain.

METHODS

Twelve male patients with chronic radicular neuropathic pain participated in a randomized, double-blind, crossover, placebo-controlled, single-administration trial. Low/high frequency (LF/HF) heart rate variability (HRV) ratio and conditioned pain modulation (CPM) response were measured and resting-state functional magnetic resonance imaging (MRI) was performed at baseline and after sublingual administration of either 0.2 mg/kg oral THC or placebo.

RESULTS

THC significantly reduced the LF/HF ratio compared with placebo (interaction effect F(1,11) = 20.5; p < 0.005) and significantly improved CPM responses (interaction effect F(1,9) = 5.2; p = 0.048). The THC-induced reduction in LF/HF ratio correlated with increased functional connectivity between the rostral ventrolateral medulla and the dorsolateral prefrontal cortex [T(10) = 6.4, cluster p-FDR < 0.005].

CONCLUSIONS

THC shifts the autonomic balance towards increased parasympathetic tone and improves inhibitory pain mechanisms in chronic pain. The increase in vagal tone correlates with connectivity changes in higher-order regulatory brain regions, suggesting THC exerts top-down effects. These changes may reflect a normalizing effect of THC on multiple domains of supraspinal pain dysregulation.

CLINICAL TRIAL REGISTRY NUMBER

NCT02560545.

Medicinal cannabis in neurodegenerative disorders: an open label, dose finding, safety and efficacy study

Aim: Currently, there exist no curative treatments for neurodegenerative disorders. Recently, there has been a resurgence of interest in the use of medicinal cannabis to improve neurological conditions. Methods: A 12-month, open label, dose-finding, safety and efficacy study was conducted including 48 subjects with a variety of neurodegenerative disorders. Results: In our participants, we observed a reduction in pain, improved sleep, enhanced well-being and less agitation. Conclusion: Our findings suggest that medicinal cannabis might be useful in patients with neurodegenerative disorders in controlling pain, enhancing sleep, reducing difficult behaviors, controlling unusual and complex symptoms when other treatments have failed - this offers medicinal cannabis a role in palliation.

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.

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.

Relationship Between Nociplastic Pain Involvement and Medication Use, Symptom Relief, and Adverse Effects Among People Using Medical Cannabis for Chronic Pain

OBJECTIVES

Cannabis is increasingly being used for chronic pain management, but cannabis' effects remain poorly characterized in chronic nociplastic pain (NPP), which is posited to be caused by disturbances in nervous system pain processing. In this cross-sectional study (n=1213), we used the 2011 Fibromyalgia (FM) Survey Criteria as a surrogate measure for degree of NPP among individuals using medical cannabis for chronic pain.

METHODS

Using a quartile-split, we investigated associations between the degree of NPP and medication use, cannabis use characteristics, and symptom relief. Continuous variables were assessed using one-way analysis of variance and categorical variables with Pearson χ 2 test and binomial logistic regression for calculation of odds ratios.

RESULTS

Participants were predominately female (59%), with a mean ± SD age of 49.4±13.6 years. Higher FM scores were associated with less self-reported improvement in pain and health since initiating medical cannabis use, as well as more cannabis-related side effects. Paradoxically, higher FM scores were also associated with higher usage of concomitant medication use (including opioids and benzodiazepines) but also with substituting cannabis for significantly more medication classes, including opioids and benzodiazepines.

DISCUSSION

This article presents evidence that individuals in higher NPP quartiles have higher analgesic intake, higher odds of substituting cannabis for medications, higher side effect burden, and lower therapeutic effect from cannabis. These seemingly contradictory findings may reflect higher symptom burden, polypharmacy at baseline, or that NPP may be challenging to treat with cannabis. Further research is necessary to further explain cannabinoid effects in NPP.

Understanding the Orthopedic Conditions for Which Patients Are Seeking Medical Cannabis Certification

BACKGROUND

Amid the ongoing national crisis of opioid misuse in the United States, medical cannabis (MC) has emerged as a potential alternative for chronic pain conditions. This study was performed to understand which orthopedic conditions patients are seeking MC certification for.

METHODS

This prospective study was conducted at the Department of Medical Cannabis, Rothman Orthopaedic Institute, Philadelphia, PA, USA. It included consecutive patients with chronic musculoskeletal noncancer pain who were certified for MC, following the Pennsylvania state certification process. Data collected included demographic data, diagnoses, anatomic site of pain, and Patient-Reported Outcomes Measurement Information System (PROMIS) global health scale. The outcome measures from the PROMIS global health scale were used to generate Global Physical Health (GPH) quality of life (QoL) T scores and Global Mental Health (GMH) QoL T scores.

RESULTS

A total of 78 patients were available for analysis following initial MC certification, with 50 (64%) being female and 28 (36%) male. The average age was 63 years with 60% of patients in the 65+ age group. Ethnically, 73 (92%) identified as White, and 70 (90%) were not of Hispanic or Latino origin. The most common reason for seeking MC certification was low back pain (56%), followed by neck pain (21%) and then extremity complaints. The mean GPH QoL T score was 43.71 with a standard deviation of ± 9.86 (p-value = 0.001), while the mean GMH QoL T score was 46.85 with a standard deviation of 8.28 (p-value = 0.0015).

CONCLUSION

MC cannabis certification was more often sought by women than men and most common for spinal complaints, specifically lower back followed by cervical spine concerns.. This cohort of patients had lower GPH QoL and GMH QoL T scores compared the US general population, representing a significant reduction in the overall physical and mental health.

Thoughtfully Integrating Cannabis Products Into Chronic Pain Treatment

Cannabis products (CPs) and cannabis-based medicines (CBMs) are becoming increasingly available and are commonly used for pain management. The growing societal acceptance of cannabis and liberalization of cannabis laws allows patients to access CPs with minimal clinical oversight. While there is mechanistic plausibility that CPs and CBMs may be useful for pain management, the clinical trial literature is limited and does not refute or support the use of CBMs for pain management. Complicating matters, a large and growing body of observational literature shows that many people use CPs for pain management and in place of other medications. However, products and dosing regimens in existing trials are not generalizable to the current cannabis market, making it difficult to compare and reconcile these 2 bodies of literature. Given this complexity, clinicians need clear, pragmatic guidance on how to appropriately educate and work with patients who are using CBMs for pain management. In this review, we narratively synthesize the evidence to enable a clear view of current landscape and provide pragmatic advice for clinicians to use when working with patients. This advice revolves around 3 principles: (1) maintaining the therapeutic alliance; (2) harm reduction and benefit maximization; and (3) pragmatism, principles of patient-centered care, and use of best clinical judgment in the face of uncertainty. Despite the lack of certainty CPs and chronic pain management use, we believe that following these principles can make most of the clinical opportunity presented by discussions around CPs and also enhance the likelihood of clinical benefit from CPs.

A preliminary study evaluating self-reported effects of cannabis and cannabinoids on neuropathic pain and pain medication use in people with spinal cord injury

Approximately 60% of individuals with a spinal cord injury (SCI) experience neuropathic pain, which often persists despite the use of various pharmacological treatments. Increasingly, the potential analgesic effects of cannabis and cannabinoid products have been studied; however, little research has been conducted among those with SCI-related neuropathic pain. Therefore, the primary objective of the study was to investigate the perceived effects of cannabis and cannabinoid use on neuropathic pain among those who were currently or had previously used these approaches. Additionally, the study aimed to determine if common pain medications are being substituted by cannabis and cannabinoids. Participants (N = 342) were recruited from existing opt-in listserv sources within the United States. Of those, 227 met the inclusion criteria and were enrolled in the study. The participants took part in an anonymous online survey regarding past and current use of cannabis and their perceived effects on neuropathic pain, including the use of pain medication. Those in the sample reported average neuropathic pain intensity scores over the past week of 6.8 ± 2.1 (0 to 10 scale), reflecting a high moderate to severe level of pain. Additionally, 87.9% noted that cannabis reduced their neuropathic pain intensity by more than 30%, and 92.3% reported that cannabis helped them to better deal with their neuropathic pain symptoms. Most participants (83.3%) also reported substituting their pain medications with cannabis, with the most substituted medication categories being opioids (47.0%), gabapentinoids (42.8%) and over-the-counter pain medications (42.2%). These preliminary results suggest that cannabis and cannabinoids may be effective in reducing neuropathic pain among those with SCI and may help to limit the need for certain pain medications.

Opioid and healthcare service use in medical cannabis patients with chronic pain: a prospective study

BACKGROUND

Various jurisdictions have legalised medical cannabis (MC) for use in chronic pain treatment. The objective of this study was to determine if the use of MC is related to a reduction in the use of prescription opioids and other prescription medications and healthcare services.

METHODS

A retrospective cohort study was conducted using the medical files of 68 Israeli patients with chronic pain using MC. Number of prescription medications filled and healthcare services used were recorded separately for the baseline period (6 months prior to the start of MC treatment) and 6 months' follow-up. Paired t-tests were used to compare each individual to himself/herself from baseline to follow-up.

RESULTS

Patients filled less opioid prescription medication at follow-up compared with baseline, and the reduction was of small effect size. There were no significant changes in the use of other medications or use of healthcare services from pre-MC treatment to follow-up.

CONCLUSIONS

MC may be related to a significant yet small reduction in opioid prescription medication. Further prospective studies with representative samples are warranted to confirm the potential small opioid-sparing effects of MC treatment, its clinical importance, if any, and potential lack of association with other healthcare-related services and medication use. Due to methodological limitations of the data used in this study, results may be regarded as preliminary and causal inferences cannot be made.

Impact of Low-Dose Dronabinol Therapy on Cognitive Function in Cancer Patients Receiving Palliative Care: A Case-Series Intervention Study

Background

Cannabis may offer therapeutic benefits to patients with advanced cancer not responding adequately to conventional palliative treatment. However, tolerability is a major concern. Cognitive function is a potential adverse reaction to tetrahydrocannabinol containing regimens. The aim of this study was to test cognitive function in patients being prescribed dronabinol as an adjuvant palliative therapy.

Methods

Adult patients with advanced cancer and severe related pain refractory to conventional palliative treatment were included in this case-series study. Patients were examined at baseline in conjunction with initiation of dronabinol therapy and at a two-week follow-up using three selected Wechsler's adult intelligence scale III neurocognitive tests: Processing Speed Index (PSI), Perceptual Organization Index (POI), and Working Memory Index (WMI). Patients were also assessed using pain visual analog scale, Major Depression Inventory, and Brief Fatigue Inventory.

Results

Eight patients consented to take part in the study. Two patients discontinued dronabinol therapy, one due to a complaint of dizziness and another critical progression of cancer disease, respectively. The remaining six patients were successfully treated with a daily dosage of 12.5 mg dronabinol (p = 0.039). PSI (p = 0.020), POI (p = 0.034.), and WMI (p = 0.039).

Conclusions

Cognitive function improved in this group of patients with advanced cancer in conjunction with low-dose dronabinol therapy. The cause is likely multifactorial including reported relief of cancer-associated symptoms. Further clinical investigation is required.

Medical Cannabis and Its Efficacy/Effectiveness for the Treatment of Low-Back Pain: a Systematic Review

PURPOSE OF REVIEW

This systematic review aims to inform the current state of evidence about the efficacy and effectiveness of medical cannabis use for the treatment of LBP, specifically on pain levels and overall opioid use for LBP. Searches were conducted in MEDLINE (PubMed), Embase, and CINAHL. The search was limited to the past 10 years (2011-2021). Study inclusion was determined by the critical appraisal process using the Joanna Briggs Institute framework. Only English language articles were included. Participant demographics included all adult individuals with LBP who were prescribed medical cannabis for LBP and may be concurrently using opioids for their LBP. Study quality and the risk of bias were both evaluated. A narrative synthesis approach was used.

RECENT FINDINGS

A total of twelve studies were included in the synthesis: one randomized controlled trial (RCT), six observational studies (one prospective, four retrospective, and one cross-over), and five case studies. All study results, except for the RCT, indicated a decrease in LBP levels or opioid use over time after medical cannabis use. The RCT reported no statistically significant difference in LBP between cannabis and placebo groups. Low back pain (LBP) affects 568 million people worldwide. In the United States, LBP treatment represents more than half of regular opioid users. With the opioid epidemic, alternative methods, particularly medical cannabis, is now increasingly sought by practicing physicians and patients. Due to its infancy, there is minimal high-quality evidence to support medical cannabis use as a first line treatment for LBP.

The holistic effects of medical cannabis compared to opioids on pain experience in Finnish patients with chronic pain

BACKGROUND

Medical cannabis (MC) is increasingly used for chronic pain, but it is unclear how it aids in pain management. Previous literature suggests that MC could holistically alter the pain experience instead of only targeting pain intensity. However, this hypothesis has not been previously systematically tested.

METHOD

A retrospective internet survey was used in a sample of Finnish chronic pain patients (40 MC users and 161 opioid users). The patients evaluated statements describing positive and negative phenomenological effects of the medicine. The two groups were propensity score matched to control for possible confounding factors.

RESULTS

Exploratory factor analysis revealed three experience factors: Negative Side Effects, Positive Holistic Effects, and Positive Emotional Effects. The MC group (matched n = 39) received higher scores than the opioid group (matched n = 39) in Positive Emotional Effects with large effect size (Rank-Biserial Correlation RBC = .71, p < .001), and in Holistic Positive Effects with medium effect size (RBC = .47, p < .001), with no difference in Negative Side Effects (p = .13). MC and opioids were perceived as equally efficacious in reducing pain intensity. Ratings of individual statements were exploratively examined in a post hoc analysis.

CONCLUSION

MC and opioids were perceived to be equally efficacious in reducing pain intensity, but MC additionally positively affected broader pain-related factors such as emotion, functionality, and overall sense of wellbeing. This supports the hypothesis that MC alleviates pain through holistically altering the pain experience.

Cannabis and Pain Control After Total Hip and Knee Arthroplasty

Cannabis use among the elderly has increased over the previous 2 decades. This has translated to a greater proportion of orthopedic procedures being undertaken on these patients. This review provides clinicians with evidence-based information on the effects of cannabis on pain control in THA and TKA, to help counsel these patients and facilitate their perioperative management. The review specifically focuses on the following: origins of cannabis; biochemistry of cannabis; medical versus recreational cannabis; pharmacology of cannabis; effects of cannabis on bone metabolism; preoperative pain control; preoperative systemic considerations; intraoperative considerations; postoperative pain control, postoperative systemic considerations; and scope for future work.

Effect of Preoperative Marijuana on Patient Outcomes and Opioid Use after Lumbar Decompression

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

Our study aims to analyze the effect of preoperative marijuana use on outcomes and postoperative opioid use in patients who have undergone lumbar decompression without fusion.

METHODS

All patients >18 years of age who underwent lumbar decompression from 2017-2022 with documented preoperative marijuana use at our academic institution were retrospectively identified. A 3:1 propensity match incorporating demographics, procedure type, and levels decompressed was performed to compare preoperative marijuana users and non-users. 1-year preoperative and postoperative opioid consumption in milligrams of morphine equivalents and postoperative outcomes including readmissions, reoperations, and complications, were obtained. A multivariate regression model was performed to measure the effect of marijuana use on the likelihood of a spine reoperation.

RESULTS

Of the 340 included patients, 85 were preoperative marijuana users. There were no significant differences in medical complications, 90-day readmissions, or opioid consumption preoperatively or postoperatively (P > .05). We identified a trend towards patients who used marijuana having more reoperations for any cause (20.0% vs 11.37%, P = .067). Multivariate logistic regression analysis suggested that preoperative marijuana use was a significant predictor of all-spine reoperations (OR = 2.06, P = .036).

CONCLUSIONS

In lumbar decompression patients, preoperative marijuana use does not impact opioid consumption, readmissions, or medical complications, but is a significant predictor of future postoperative reoperations. Additional research is necessary to further explore the role of marijuana use in spine surgery.

"I still partly think this is bullshit": A qualitative analysis of cannabinoid hyperemesis syndrome perceptions among people with chronic cannabis use and cyclic vomiting

BACKGROUND

Cannabis is the most widely used psychoactive substance in the United States (US), with reported use patterns increasing among adults in recent years. Cannabinoid hyperemesis syndrome (CHS) has been one concern related to increased cannabis use patterns. US emergency departments have reported an increase of CHS cases over the last decade, yet little is known about CHS. This study explores the experiences of people with chronic cannabis use and cyclic vomiting and their perceptions of CHS.

METHODS

Semi-structured interviews were conducted with 24 people recruited from a prospective cohort of patients presenting to Rhode Island emergency departments with symptomatic cyclic vomiting and chronic cannabis use. Data were analyzed thematically using NVivo.

FINDINGS

Participants characterized their cyclic vomiting as related to food and alcohol consumption patterns, stress, and existing gastrointestinal issues. Despite recurrent episodes of cyclic vomiting, nausea, and abdominal pain, many participants remained uncertain whether their symptoms were driven by cannabis. Many participants relied on at-home research to assess their symptoms and seek out management approaches. Clinical treatment recommendations focused on cannabis cessation. However, most participants felt clinical recommendations failed to consider the complexity and challenge of stopping cannabis use given the chronicity of use and therapeutic benefits some perceived cannabis to have.

CONCLUSIONS

Although cannabis cessation is the only reported CHS cure to date, additional clinical and non-clinical treatment approaches are needed to better support people with chronic cannabis use and cyclic vomiting to meet their ongoing needs.

Assessment of Medical Cannabis and Health-Related Quality of Life

Importance

The use of cannabis as a medicine is becoming increasingly prevalent. Given the diverse range of conditions being treated with medical cannabis, as well as the vast array of products and dose forms available, clinical evidence incorporating patient-reported outcomes may help determine safety and efficacy.

Objective

To assess whether patients using medical cannabis report improvements in health-related quality of life over time.

Design, Setting, and Participants

This retrospective case series study was conducted at a network of specialist medical clinics (Emerald Clinics) located across Australia. Participants were patients who received treatment for any indication at any point between December 2018 and May 2022. Patients were followed up every mean (SD) 44.6 (30.1) days. Data for up to 15 follow-ups were reported. Statistical analysis was conducted from August to September 2022.

Exposure

Medical cannabis. Product types and cannabinoid content varied over time in accordance with the treating physician's clinical judgement.

Main Outcomes and Measures

The main outcome measure was health-related quality of life as assessed using the 36-Item Short Form Health Survey (SF-36) questionnaire.

Results

In this case series of 3148 patients, 1688 (53.6%) were female; 820 (30.2%) were employed; and the mean (SD) age was 55.9 (18.7) years at baseline before treatment. Chronic noncancer pain was the most common indication for treatment (68.6% [2160 of 3148]), followed by cancer pain (6.0% [190 of 3148]), insomnia (4.8% [152 of 3148]), and anxiety (4.2% [132 of 3148]). After commencing treatment with medical cannabis, patients reported significant improvements relative to baseline on all 8 domains of the SF-36, and these improvements were mostly sustained over time. After controlling for potential confounders in a regression model, treatment with medical cannabis was associated with an improvement of 6.60 (95% CI, 4.57-8.63) points to 18.31 (95% CI, 15.86-20.77) points in SF-36 scores, depending on the domain (all P < .001). Effect sizes (Cohen d) ranged from 0.21 to 0.72. A total of 2919 adverse events were reported, including 2 that were considered serious.

Conclusions and Relevance

In this case series study, patients using medical cannabis reported improvements in health-related quality of life, which were mostly sustained over time. Adverse events were rarely serious but common, highlighting the need for caution with prescribing medical cannabis.

Medical Cannabis for Chronic Nonmalignant Pain Management

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

Development of cannabis use disorder in medical cannabis users: A 9-month follow-up of a randomized clinical trial testing effects of medical cannabis card ownership

Background

Evidence for long-term effectiveness of commercial cannabis products used to treat medical symptoms is inconsistent, despite increasingly widespread use.

Objective

To prospectively evaluate the effects of using cannabis on self-reported symptoms of pain, insomnia, anxiety, depression, and cannabis use disorder (CUD) after 12 months of use.

Methods

This observational cohort study describes outcomes over 9 months following a 12-week randomized, waitlist-controlled trial (RCT: NCT03224468) in which adults (N = 163) who wished to use cannabis to alleviate insomnia, pain, depression, or anxiety symptoms were randomly assigned to obtain a medical marijuana card immediately (immediate card acquisition group) or to delay obtaining a card for 12 weeks delay (delayed card acquisition group). During the 9-month post-randomization period, all participants could use cannabis as they wished and choose their cannabis products, doses, and frequency of use. Insomnia, pain, depression, anxiety, and CUD symptoms were assessed over the 9-month post-randomization period.

Results

After 12 months of using cannabis for medical symptoms, 11.7% of all participants (n = 19), and 17.1% of those using cannabis daily or near-daily (n = 6) developed CUD. Frequency of cannabis use was positively correlated with pain severity and number of CUD symptoms, but not significantly associated with severity of self-reported insomnia, depression, or anxiety symptoms. Depression scores improved throughout the 9 months in all participants, regardless of cannabis use frequency.

Conclusions

Frequency of cannabis use was not associated with improved pain, anxiety, or depression symptoms but was associated with new-onset cannabis use disorder in a significant minority of participants. Daily or near-daily cannabis use appears to have little benefit for these symptoms after 12 months of use.

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.

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.

Wellness of patients with chronic pain is not only about pain intensity

OBJECTIVE

Attaining good outcomes in the management of chronic pain remains a clinical challenge. This study aimed to investigate the relationships between - and the contribution of - pain and related conditions to the wellness of these patients.

DESIGN

A secondary analysis of database of patients with chronic pain treated with medical cannabis (MC) to carry out a one-year prospective follow-up study was conducted. Questionnaires were completed before (T₀ ), six (T₆ ), and twelve (T₁₂ ) months after MC initiation. Data included patients' demographics and questionnaires related to three latent factors: pain intensity measures, related conditions (catastrophizing, sleep disturbance, anxiety, and depression), and wellness parameters (quality-of-life, disability, subjective-health-state). Weighted average of the observed variables (WOBs) were calculated for each latent factor. Longitudinal structural equation modeling (SEM) and mediation analyses were performed to identify predictors and interrelations between the WOBs, respectively.

RESULTS

Participants included 510 patients. All variables were significantly improved from T₀ to T₆ and T₁₂ . SEM revealed that related conditions, and to a lesser extent pain, predicted wellness at T₀ , T₆ , and T₁₂ (related conditions: β₀  = 0.55, p < 0.001; β₆  = 0.54, p < 0.001; and β₁₂  = 0.51, p < 0.001; pain: β₀  = 0.42, p < 0.001; β₆  = 0.18, p < 0.001; and β₁₂  = 0.25, p < 0.001). Mediation analyses demonstrated that the effect of WOB-related conditions was greater than WOB-pain on wellness.

CONCLUSION

Wellness of patients with chronic pain can be determined not only by pain itself but even more so by the severity of related conditions. Thus, considering a broad spectrum of pain measures and related conditions seems relevant for improving the wellness of patients with chronic pain.

Quality of Life in Patients Receiving Medical Cannabis

INTRODUCTION

Medical cannabis has been used to relieve the symptoms of people with various chronic diseases. Despite of this, it has been stigmatized, even after its legalization in many countries.

AIM

The purpose of this study was to investigate the quality of life of patients receiving medical cannabis.

MATERIAL AND METHOD

One hundred patients receiving medical cannabis were given (a) a socio-demographic and clinical questionnaire, and (b) the SF-36 Health Survey scale for assessing quality of life.

RESULTS

The majority of our patients who received medical cannabis to treat their neurological disorders (58%) reported decrease in their symptoms (96%), better energy and vitality (68%), ability to perform their professional duties (88%), and an improvement in sleeping and appetite (79% and 71%, respectively) after receiving medical cannabis. Our participants exhibited very few restrictions in activities due to emotional difficulties, a moderate general health status as well as moderate vitality and energy. Participants, who reported a longer period of receiving medical cannabis, reported statistically significant more energy and vitality (p = 0.000), but also better mental (p = 0.000) and general health status (p = 0.001). Furthermore, the majority of patients have disclosed medical cannabis use to their family members (85%) and enjoyed their support (93%), but they haven't revealed their medication treatment to their social environment (81%).

CONCLUSIONS

Appropriate knowledge could significantly help health professionals in the field of planning and implementation of personalized nursing care in order to achieve optimal therapeutic outcomes.

Perceived Efficacy, Reduced Prescription Drug Use, and Minimal Side Effects of Cannabis in Patients with Chronic Orthopedic Pain

Introduction: Although cannabis is widely used for the treatment of chronic pain, most research relies on patient self-report and few studies have objectively quantified its efficacy and side effects. Extant inventories for measuring cannabis use were not designed to capture the medically relevant features of cannabis use, but rather were designed to detect problematic use or cannabis use disorder. Thus, we sought to capture the medically relevant features of cannabis use in a population of patients with orthopedic pain and pair these data with objective measures of pain and prescription drug use. Materials and Methods: In this prospective observational study, orthopedic pain patients were enrolled in Pennsylvania's medical cannabis program by their treating pain management physician, received cannabis education from their physician at the time of certification, and purchased products from state-licensed cannabis retailers. Results: Medical cannabis use was associated with clinical improvements in pain, function, and quality of life with reductions in prescription drug use; 73% either ceased or decreased opioid consumption and 31% discontinued benzodiazepines. Importantly, 52% of patients did not experience intoxication as a side effect of cannabis therapy. Significant clinical benefits of cannabis occurred within 3 months of initiating cannabis therapy and plateaued at the subsequent follow-ups. Conclusions: This work provides a direct relationship between the initiation of cannabis therapy and objectively fewer opioid and benzodiazepine prescriptions. Our work also identifies specific subpopulations of patients for whom cannabis may be most efficacious in reducing opioid consumption, and it highlights the importance of both physician involvement and patient self-titration in symptom management with cannabis.

Marijuana Use and its Effect on Clinical Outcomes and Revision Rates in Patients Undergoing Anterior Cervical Discectomy and Fusion

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To determine if (1) preoperative marijuana use increased complications, readmission, or reoperation rates following anterior cervical discectomy and fusion (ACDF), (2) identify if preoperative marijuana use resulted in worse patient-reported outcome measures (PROMs), and (3) investigate if preoperative marijuana use affects the quantity of opioid prescriptions in the perioperative period.

SUMMARY OF BACKGROUND DATA

A growing number of states have legalized recreational and/or medical marijuana, thus increasing the number of patients who report preoperative marijuana use. The effects of marijuana on clinical outcomes and PROMs in the postoperative period are unknown.

METHODS

All patients 18 years of age and older who underwent primary one- to four-level ACDF with preoperative marijuana use at our academic institution were retrospectively identified. A 3:1 propensity match was conducted to compare patients who used marijuana versus those who did not. Patient demographics, surgical characteristics, clinical outcomes, and PROMs were compared between groups. Multivariate regression models measured the effect of marijuana use on the likelihood of requiring a reoperation and whether marijuana use predicted inferior PROM improvements at the one-year postoperative period.

RESULTS

Of the 240 patients included, 60 (25.0%) used marijuana preoperatively. Multivariate logistic regression analysis identified marijuana use (odds ratio=5.62, P <0.001) as a predictor of a cervical spine reoperation after ACDF. Patients who used marijuana preoperatively had worse one-year postoperative Physical Component Scores of the Short-Form 12 (PCS-12) ( P =0.001), Neck Disability Index ( P =0.003), Visual Analogue Scale (VAS) Arm ( P =0.044) and VAS Neck ( P =0.012). Multivariate linear regression found preoperative marijuana use did not independently predict improvement in PCS-12 (β=-4.62, P =0.096), Neck Disability Index (β=9.51, P =0.062), Mental Component Scores of the Short-Form 12 (MCS-12) (β=-1.16, P =0.694), VAS Arm (β=0.06, P =0.944), or VAS Neck (β=-0.44, P =0.617).

CONCLUSION

Preoperative marijuana use increased the risk of a cervical spine reoperation after ACDF, but it did not significantly change the amount of postoperative opioids used or the magnitude of improvement in PROMs.

LEVEL OF EVIDENCE

Levwl III.

Pilot clinical and pharmacokinetic study of Δ9-Tetrahydrocannabinol (THC)/Cannabidiol (CBD) nanoparticle oro-buccal spray in patients with advanced cancer experiencing uncontrolled pain

This pilot study aimed to assess the safety, tolerability, pharmacokinetics and exploratory analgesic effect of a novel water-soluble oro-buccal nanoparticle spray of a cannabis-based medicine (MDCNS-01) in patients with advanced incurable malignancy with unrelieved pain from opioid analgesic. The study was a non-blinded single arm 2 stage study. Stage I was a single escalating dose (n = 5) [2.5 mg Δ9-THC and 2.5 mg CBD) versus a 3-fold escalated dose. Stage II was an up-titrated dose in patients with advanced cancers and intractable pain (n = 25). During Stage I with an increased cannabis-based medicine dose, maximum observed plasma concentrations of cannabinoids were dose dependant. The water-soluble formulation in the current study resulted in a higher median (min, max) systemic exposure of Δ9-THC than CBD (AUC from 2.5 mg each of Δ9-THC and CBD, was 1.71 ng mL.h-1 (1.1, 6.6) and 0.65 ng mL.h-1 (0.49, 4.1), respectively). During stage II a subgroup of patients diagnosed with breast and prostate cancers with bone metastases, had the highest mean pain score improvement from baseline of 40% (unadjusted) and 33% (adjusted for rescue medication use). For all patients the most reported adverse events were mild or moderate drowsiness affecting 11 (44%) and 4 (6%) patients, respectively, and nausea and vomiting that affected 18 (72%) patients. The water-soluble cannabis-based medicine provided acceptable bioavailability for Δ9-THC/CBD, appeared safe and tolerable in advanced incurable cancers with uncontrolled pain with preliminary evidence of analgesic efficacy.

Brain Penetrant, but not Peripherally Restricted, Synthetic Cannabinoid 1 Receptor Agonists Promote Morphine-Mediated Respiratory Depression

Introduction: Cannabis acceptance and use continues to rise despite the gaps in knowledge regarding the mechanisms of cannabinoids and the endocannabinoid system in many physiological functions, including respiratory influence. Methods: With recent evidence of cannabinoid receptor 1 (CB1R) presence in the collection of respiratory neurons in the brainstem, as well as in the peripheral lung tissue, it is vital that the mechanisms involved in central and peripheral CB1R modulation of respiratory function be delineated. In this study we sought to define the roles of central versus peripheral CB1R activation on respiratory depression alone and in combination with morphine using whole body plethysmography. Results: We show that the peripherally restricted CB1 agonist (4-{2-[-(1E)-1[(4-propylnaphthalen-1-yl)methylidene]-1H-inden-3yl]ethyl}morpholine [PrNMI] 0.3, 0.6, and 1 mg/kg) does not induce respiratory depression, while our previous studies showed that a central penetrating synthetic cannabinoid does induce respiratory depression. Significantly, the combination of morphine with the peripheral CB1 agonist, PrNMI, attenuated morphine-induced respiratory depression. Conclusions: These studies support that a peripherally restricted CB1R agonist may be a unique strategy to attenuate the respiratory depression associated with opioid therapy.

Assessment of delta-9-tetrahydrocannabinol (THC) in saliva and blood after oral administration of medical cannabis with respect to its effect on driving abilities

Medical cannabis has recently been legalized in many countries, and it is currently prescribed with increasing frequency, particularly for treatment of chronic pain resistant to conventional therapy. The psychoactive substance delta-9-tetrahydro-cannabinol (THC) contained in cannabis may affect driving abilities. Therefore, the aims of this study (open-label, monocentric, nonrandomized) were to evaluate blood and saliva concentrations of THC after oral administration of medical cannabis and to assess the time needed for THC levels to decline below a value ensuring legal driving. The study involved 20 patients with documented chronic pain using long-term medical cannabis therapy. They were divided into two groups and treated with two different doses of cannabis in the form of gelatin capsules (62.5 mg or 125 mg). In all patients, the amount of THC was assessed in saliva and in blood at pre-defined time intervals before and after administration. THC levels in saliva were detected at zero in all subjects following administration of both doses at all-time intervals after administration. Assessment of THC levels in blood, however, showed positive findings in one subject 9 h after administration of the lower dose and in one patient who had been given a higher dose 7 h after administration. Our finding suggested that for an unaffected ability to drive, at least 9-10 h should elapse from the last cannabis use.

The association between cannabis and codeine use: a nationally representative cross-sectional study in Canada

Background

Due to the growing use of cannabis for the purposes of pain relief, evidence is needed on the impact of cannabis use on concurrent analgesic use. Therefore, our objective was to evaluate the association between the use of cannabis and codeine.

Methods

We conducted a cross-sectional study using data from the nationally representative Canadian Tobacco, Alcohol and Drugs Survey (2017). The primary explanatory variable was self-reported use of cannabis within the past year. The outcome was the use of codeine-containing product(s) within the past year. We used multivariable binomial logistic regression models.

Results

Our study sample comprised 15,459 respondents including 3338 individuals who reported cannabis use within the past year of whom 955 (36.2%) used it for medical purposes. Among individuals who reported cannabis use, the majority were male (N = 1833, 62.2%). Self-reported use of cannabis was associated with codeine use (adjusted odds ratio [aOR] 1.89, 95% CI 1.36 to 2.62). Additionally, when limited to cannabis users only, we found people who used cannabis for medical purposes to be three times more likely to also report codeine use (adjusted odds ratio [aOR] 2.96, 95% CI 1.72 to 5.09).

Discussion

The use of cannabis was associated with increased odds of codeine use, especially among individuals who used it for medical purposes. Our findings suggest a potential role for healthcare providers to be aware of or monitor patients’ use of cannabis, as the long-term adverse events associated with concurrent cannabis and opioid use remain unknown.

The Use of Cannabidiol in Patients With Low Back Pain Caused by Lumbar Spinal Stenosis: An Observational Study

Background Spinal stenosis is a degenerative narrowing of the spinal canal with encroachment on the neural structures by surrounding bone and soft tissue. This chronic low back condition can cause restrictions in mobility, impairment of daily activities, opioid dependence, anxiety, depression, and reduced quality of life. Spinal stenosis can be treated through surgical and nonsurgical methods, but neither has proven consistently reliable. Cannabidiol (CBD) has also been observed to have anxiolytic, anti-inflammatory, antiemetic, and antipsychotic behaviors. CBD may provide greater nonsurgical treatment options for the pain associated with spinal stenosis while minimizing the need for opioids. An observational study was undertaken to assess the effects of CBD on patients suffering from chronic spinal stenosis. Methodology This observational study was investigator-initiated and designed to determine the effect of hemp-derived CBD gel caps for patients with spinal stenosis related to low back pain and leg pain relative to patient outcomes, medication utilization, and quality of life outcome measures. A total of six physician visits would be required where a set of surveys would be filled out each four weeks apart. Results The study population consisted of 48 patients. The patient population's age ranged from 63 to 95 years and was normally distributed, with a mean age of 75 ± 7.13 years. The sex distribution was 33% male and 67% female patients. The pain was broken down between the six visits for each of the following four questions: pain right now, usual pain level during the week, best pain level during the week, and worst pain level during the week. Usual pain levels (p < 0.001) and worst pain levels (p < 0.005) demonstrated statistically significant improvement over time, while pain right now (p > 0.05) and best pain level (p > 0.05) stayed consistent throughout without statistical significance. Conclusions This open-label, prospective, observational study found that treatment with hemp-derived CBD gel caps was associated with significant improvements in pain scores and several quality-of-life measures for patients with lumbar spinal stenosis.

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.

Long-term and serious harms of medical cannabis and cannabinoids for chronic pain: a systematic review of non-randomised studies

OBJECTIVE

To establish the prevalence of long-term and serious harms of medical cannabis for chronic pain.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, EMBASE, PsycINFO and CENTRAL from inception to 1 April 2020.

STUDY SELECTION

Non-randomised studies reporting on harms of medical cannabis or cannabinoids in adults or children living with chronic pain with ≥4 weeks of follow-up.

DATA EXTRACTION AND SYNTHESIS

A parallel guideline panel provided input on the design and interpretation of the systematic review, including selection of adverse events for consideration. Two reviewers, working independently and in duplicate, screened the search results, extracted data and assessed risk of bias. We used random-effects models for all meta-analyses and the Grades of Recommendations, Assessment, Development and Evaluation approach to evaluate the certainty of evidence.

RESULTS

We identified 39 eligible studies that enrolled 12 143 adult patients with chronic pain. Very low certainty evidence suggests that adverse events are common (prevalence: 26.0%; 95% CI 13.2% to 41.2%) among users of medical cannabis for chronic pain, particularly any psychiatric adverse events (prevalence: 13.5%; 95% CI 2.6% to 30.6%). Very low certainty evidence, however, indicates serious adverse events, adverse events leading to discontinuation, cognitive adverse events, accidents and injuries, and dependence and withdrawal syndrome are less common and each typically occur in fewer than 1 in 20 patients. We compared studies with <24 weeks and ≥24 weeks of cannabis use and found more adverse events reported among studies with longer follow-up (test for interaction p<0.01). Palmitoylethanolamide was usually associated with few to no adverse events. We found insufficient evidence addressing the harms of medical cannabis compared with other pain management options, such as opioids.

CONCLUSIONS

There is very low certainty evidence that adverse events are common among people living with chronic pain who use medical cannabis or cannabinoids, but that few patients experience serious adverse events.

Predictors of Pain Reduction Among Fibromyalgia Patients Using Medical Cannabis: A Long-Term Prospective Cohort Study

OBJECTIVE

Many patients with fibromyalgia (FM) report using cannabis as a strategy to improve pain. Given that pain often co-occurs with symptoms of anxiety and depression (i.e., negative affect) and sleep problems among patients with FM, improvements in these symptoms might indirectly contribute to reductions in pain intensity following cannabis use. The main objective of the study was to examine whether changes in pain intensity following initiation of medical cannabis among patients with FM could be attributed to concurrent changes (i.e., reductions) in negative affect and sleep problems.

METHODS

This was a 12-month prospective cohort study among patients with FM (n = 323) initiating medical cannabis under the care of physicians. Patients were assessed at baseline, and follow-up assessment visits occurred every 3 months after initiation of medical cannabis. Patients' levels of pain intensity, negative affect, and sleep problems were assessed across all visits.

RESULTS

Multilevel mediation analyses indicated that reductions in patients' levels of pain intensity were partly explained by concurrent reductions in sleep problems and negative affect (both P < 0.001). This remained significant even when accounting for patients' baseline characteristics or changes in medical cannabis directives over time (all P > 0.05).

CONCLUSION

Our findings provide preliminary insight into the potential mechanisms of action underlying pain reductions among patients with FM who are using medical cannabis. Given the high attrition rate (i.e., 75%) observed in the present study at 12 months, our findings cannot be generalized to all patients with FM who are using medical cannabis.

Opioid-sparing effect of cannabinoids for analgesia: an updated systematic review and meta-analysis of preclinical and clinical studies

Cannabinoid co-administration may enable reduced opioid doses for analgesia. This updated systematic review on the opioid-sparing effects of cannabinoids considered preclinical and clinical studies where the outcome was analgesia or opioid dose requirements. We searched Scopus, Cochrane Central Registry of Controlled Trials, Medline, and Embase (2016 onwards). Ninety-two studies met the search criteria including 15 ongoing trials. Meta-analysis of seven preclinical studies found the median effective dose (ED₅₀) of morphine administered with delta-9-tetrahydrocannabinol was 3.5 times lower (95% CI 2.04, 6.03) than the ED₅₀ of morphine alone. Six preclinical studies found no evidence of increased opioid abuse liability with cannabinoid administration. Of five healthy-volunteer experimental pain studies, two found increased pain, two found decreased pain and one found reduced pain bothersomeness with cannabinoid administration; three demonstrated that cannabinoid co-administration may increase opioid abuse liability. Three randomized controlled trials (RCTs) found no evidence of opioid-sparing effects of cannabinoids in acute pain. Meta-analysis of four RCTs in patients with cancer pain found no effect of cannabinoid administration on opioid dose (mean difference -3.8 mg, 95% CI -10.97, 3.37) or percentage change in pain scores (mean difference 1.84, 95% CI -2.05, 5.72); five studies found more adverse events with cannabinoids compared with placebo (risk ratio 1.13, 95% CI 1.03, 1.24). Of five controlled chronic non-cancer pain trials; one low-quality study with no control arm, and one single-dose study reported reduced pain scores with cannabinoids. Three RCTs found no treatment effect of dronabinol. Meta-analyses of observational studies found 39% reported opioid cessation (95% CI 0.15, 0.64, I² 95.5%, eight studies), and 85% reported reduction (95% CI 0.64, 0.99, I² 92.8%, seven studies). In summary, preclinical and observational studies demonstrate the potential opioid-sparing effects of cannabinoids in the context of analgesia, in contrast to higher-quality RCTs that did not provide evidence of opioid-sparing effects.

The Effectiveness and Safety of Medical Cannabis for Treating Cancer Related Symptoms in Oncology Patients

The use of medical cannabis (MC) to treat cancer-related symptoms is rising. However, there is a lack of long-term trials to assess the benefits and safety of MC treatment in this population. In this work, we followed up prospectively and longitudinally on the effectiveness and safety of MC treatment. Oncology patients reported on multiple symptoms before and after MC treatment initiation at one-, three-, and 6-month follow-ups. Oncologists reported on the patients' disease characteristics. Intention-to-treat models were used to assess changes in outcomes from baseline. MC treatment was initiated by 324 patients and 212, 158 and 126 reported at follow-ups. Most outcome measures improved significantly during MC treatment for most patients (p < 0.005). Specifically, at 6 months, total cancer symptoms burden declined from baseline by a median of 18%, from 122 (82-157) at baseline to 89 (45-138) at endpoint (-18.98; 95%CI= -26.95 to -11.00; p < 0.001). Reported adverse effects were common but mostly non-serious and remained stable during MC treatment. The results of this study suggest that MC treatment is generally safe for oncology patients and can potentially reduce the burden of associated symptoms with no serious MC-related adverse effects.

The phytochemical diversity of commercial Cannabis in the United States

The legal status of Cannabis is changing, fueling an increasing diversity of Cannabis-derived products. Because Cannabis contains dozens of chemical compounds with potential psychoactive or medicinal effects, understanding this phytochemical diversity is crucial. The legal Cannabis industry heavily markets products to consumers based on widely used labeling systems purported to predict the effects of different "strains." We analyzed the cannabinoid and terpene content of commercial Cannabis samples across six US states, finding distinct chemical phenotypes (chemotypes) which are reliably present. By comparing the observed phytochemical diversity to the commercial labels commonly attached to Cannabis-derived product samples, we show that commercial labels do not consistently align with the observed chemical diversity. However, certain labels do show a biased association with specific chemotypes. These results have implications for the classification of commercial Cannabis, design of animal and human research, and regulation of consumer marketing-areas which today are often divorced from the chemical reality of the Cannabis-derived material they wish to represent.

Sex differences in medical cannabis-related adverse effects

ABSTRACT

Studies have shown that women are more susceptible to adverse effects (AEs) from conventional drugs. This study aimed to investigate the differences of medical cannabis (MC)-related AEs between women and men in patients with chronic noncancer pain (CNCP). This is a cross-sectional study of adult patients licensed for MC treatment who were also diagnosed as patients with CNCP by a physician. Data included self-reported questionnaires and comprehensive MC treatment information. Simultaneously, identification and quantification of phytocannabinoids and terpenoids from the MC cultivars were performed. Comparative statistics were used to evaluate differences between men and women. Four hundred twenty-nine patients with CNCP (64% males) reported fully on their MC treatment. Subgrouping by sex demonstrated that the weight-adjusted doses were similar between men and women (0.48 [0.33-0.6] gr for men and 0.47 [0.34-0.66] gr for women). Nonetheless, women reported more than men on MC-related AEs. Further analysis revealed that women consumed different MC cultivar combinations than men, with significantly higher monthly doses of the phytocannabinoids CBD and CBC and significantly lower monthly doses of the phytocannabinoid 373-15c and the terpenoid linalool. Our findings demonstrate sex differences in MC-related AEs among patients with CNCP. Women are more susceptible to MC-related AEs, presumably because of both the inherent sex effect and the consumption of specific phytocannabinoid compositions in the MC cultivar(s). The understanding of these differences may be crucial for planning MC treatments with safer phytocannabinoid and terpenoid compositions and to better inform patients of expected AEs.

Developing a real-world evidence base for prescribed cannabis in the United Kingdom: preliminary findings from Project Twenty21

The therapeutic potential of medical cannabis to treat a variety of conditions is becoming increasingly recognised. Globally, a large number of countries have now legalised cannabis for medical uses and a substantial number of patients are able to access their medications. Yet in the UK, where medical cannabis was legalised in November 2018, only a handful of NHS prescriptions have been written, meaning that most patients are unable to access the medicine. Reasons for this are manyfold and include the perceived lack of clinical evidence due to the challenges of studying medical cannabis through randomised controlled trials. In order to develop the current evidence base, the importance of incorporating real-world data (RWD) to assess the effectiveness and efficacy of medical cannabis has gradually become recognised. The current paper provides a detailed outline of Project Twenty21 (T21), the UK's first medical cannabis registry, launched in August 2020. We provide the rationale for T21 and describe the methodology before reporting the characteristics of the 'first patients' enrolled in the registry. We describe the health status of all patients enrolled into the project during its first 7 months of operation and the sociodemographic characteristics and primary presenting conditions for these patients, as well as details of the medical cannabis prescribed to these individuals. By 12th March 2021, 678 people had been enrolled into T21; the majority (64%) were male and their average age was 38.7 years (range = 18-80). The most commonly reported primary conditions were chronic pain (55.6%) and anxiety disorders (32.0%) and they reported high levels of multi-morbidity, including high rates of insomnia and depression. We also present preliminary evidence from 75 patients followed up after 3 months indicating that receipt of legal, prescribed cannabis was associated with a significant increase in self-reported health, assessed using the visual analogue scale of the EQ-5D-5L (Cohen's d = .77, 95% CI = .51-1.03). Our initial findings complement reports from other large-scale databases globally, indicating that the current RWD is building up a pattern of evidence. With many clinicians demanding better and faster evidence to inform their decisions around prescribing medical cannabis, the current and future results of T21 will expand the existing evidence base on the effectiveness of cannabis-based medical products (CBMPs).

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

BACKGROUND AND OBJECTIVE

This systematic review evaluated the effectiveness, tolerability and safety of cannabis-based medicines (CbMs) for chronic non-cancer pain (CNCP) in long-term observational studies.

DATABASES AND DATA TREATMENT

CENTRAL, EMBASE and MEDLINE were searched to December 2021. We included prospective observational studies with a study duration ≥ 26 weeks. Pooled estimates of event rates of categorical data and standardized mean differences (SMD) of continuous variables were calculated using a random effects model.

RESULTS

Six studies were included with 2686 participants, with study duration ranging between 26 and 52 weeks. Pain conditions included were nociceptive, nociplastic, neuropathic and mixed pain. The certainty of evidence for every outcome was very low. The weighted mean difference of mean pain reduction was 1.75 (95% Confidence interval [CI] 0.72 to 2.78) on a 0-10 scale. 20.8 % (95% CI 10.2 % to 34.0 %) of patients reported pain relief of 50% or greater. The effect size for sleep problems was moderate and for depression and anxiety was low. Study completions was reported for 53.3% (95% CI 26.8% to 79.9%) of patients, with dropouts of 6.8 % (95% CI 4.3% to 9.7%) due to adverse events. Serious adverse events occurred in 3.0% (95 CI 0.02 % to 12.8%) and 0.3 % (95% CI 0.1% to 0.6%) of patients died.

CONCLUSIONS

Information included in observational studies should be regarded with caution.Within the context of observational studies, CbMs had positive effects on multiple symptoms for some CNCP patients and were generally well tolerated and safe.

Medicinal Cannabis and Central Nervous System Disorders

Cannabinoids, including those found in cannabis, have shown promise as potential therapeutics for numerous health issues, including pathological pain and diseases that produce an impact on neurological processing and function. Thus, cannabis use for medicinal purposes has become accepted by a growing majority. However, clinical trials yielding satisfactory endpoints and unequivocal proof that medicinal cannabis should be considered a frontline therapeutic for most examined central nervous system indications remains largely elusive. Although cannabis contains over 100 + compounds, most preclinical and clinical research with well-controlled dosing and delivery methods utilize the various formulations of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), the two most abundant compounds in cannabis. These controlled dosing and delivery methods are in stark contrast to most clinical studies using whole plant cannabis products, as few clinical studies using whole plant cannabis profile the exact composition, including percentages of all compounds present within the studied product. This review will examine both preclinical and clinical evidence that supports or refutes the therapeutic utility of medicinal cannabis for the treatment of pathological pain, neurodegeneration, substance use disorders, as well as anxiety-related disorders. We will predominately focus on purified THC and CBD, as well as other compounds isolated from cannabis for the aforementioned reasons but will also include discussion over those studies where whole plant cannabis has been used. In this review we also consider the current challenges associated with the advancement of medicinal cannabis and its derived potential therapeutics into clinical applications.

Medicinal Cannabis and Central Nervous System Disorders

Cannabinoids, including those found in cannabis, have shown promise as potential therapeutics for numerous health issues, including pathological pain and diseases that produce an impact on neurological processing and function. Thus, cannabis use for medicinal purposes has become accepted by a growing majority. However, clinical trials yielding satisfactory endpoints and unequivocal proof that medicinal cannabis should be considered a frontline therapeutic for most examined central nervous system indications remains largely elusive. Although cannabis contains over 100 + compounds, most preclinical and clinical research with well-controlled dosing and delivery methods utilize the various formulations of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), the two most abundant compounds in cannabis. These controlled dosing and delivery methods are in stark contrast to most clinical studies using whole plant cannabis products, as few clinical studies using whole plant cannabis profile the exact composition, including percentages of all compounds present within the studied product. This review will examine both preclinical and clinical evidence that supports or refutes the therapeutic utility of medicinal cannabis for the treatment of pathological pain, neurodegeneration, substance use disorders, as well as anxiety-related disorders. We will predominately focus on purified THC and CBD, as well as other compounds isolated from cannabis for the aforementioned reasons but will also include discussion over those studies where whole plant cannabis has been used. In this review we also consider the current challenges associated with the advancement of medicinal cannabis and its derived potential therapeutics into clinical applications.

Efficacy of interventions to reduce long term opioid treatment for chronic non-cancer pain: systematic review and meta-analysis

OBJECTIVE

To review interventions to reduce long term opioid treatment in people with chronic non-cancer pain, considering efficacy on dose reduction and discontinuation, pain, function, quality of life, withdrawal symptoms, substance use, and adverse events.

DESIGN

Systematic review and meta-analysis of randomised controlled trials and non-randomised studies of interventions.

DATA SOURCES

Medline, Embase, PsycINFO, CINAHL, and the Cochrane Library searched from inception to July 2021. Reference lists and previous reviews were also searched and experts were contacted.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Original research in English. Case reports and cross sectional studies were excluded.

DATA EXTRACTION AND SYNTHESIS

Two authors independently selected studies, extracted data, and used the Cochrane risk-of-bias tools for randomised and non-randomised studies (RoB 2 and ROBINS-I). Authors grouped interventions into five categories (pain self-management, complementary and alternative medicine, pharmacological and biomedical devices and interventions, opioid replacement treatment, and deprescription methods), estimated pooled effects using random effects meta-analytical models, and appraised the certainty of evidence using GRADE (grading of recommendations, assessment, development, and evaluation).

RESULTS

Of 166 studies meeting inclusion criteria, 130 (78%) were considered at critical risk of bias and were excluded from the evidence synthesis. Of the 36 included studies, few had comparable treatment arms and sample sizes were generally small. Consequently, the certainty of the evidence was low or very low for more than 90% (41/44) of GRADE outcomes, including for all non-opioid patient outcomes. Despite these limitations, evidence of moderate certainty indicated that interventions to support prescribers' adherence to guidelines increased the likelihood of patients discontinuing opioid treatment (adjusted odds ratio 1.5, 95% confidence interval 1.0 to 2.1), and that these prescriber interventions as well as pain self-management programmes reduced opioid dose more than controls (intervention v control, mean difference -6.8 mg (standard error 1.6) daily oral morphine equivalent, P<0.001; pain programme v control, -14.31 mg daily oral morphine equivalent, 95% confidence interval -21.57 to -7.05).

CONCLUSIONS

Evidence on the reduction of long term opioid treatment for chronic pain continues to be constrained by poor study methodology. Of particular concern is the lack of evidence relating to possible harms. Agreed standards for designing and reporting studies on the reduction of opioid treatment are urgently needed.

REVIEW REGISTRATION

PROSPERO CRD42020140943.