Cannabis and Pain Treatment-A Review of the Clinical Utility and a Practical Approach in Light of Uncertainty

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.

The Association of Medical Cannabis Use with Pain Levels and Opioid Use in Illinois' Opioid Alternative Pilot Program

OBJECTIVE

The state of Illinois' Opioid Alternative Pilot Program (OAPP) is the first and only official harm-reduction program in the US to address the opioid crisis via facilitation of safe and legal access to medical cannabis. This study evaluates the association of medical cannabis use with pain level and frequency of opioid use in the first cohort of OAPP participants in 2019.

METHODS

A survey was sent OAPP enrollees between February and July 2019. Cannabis users (n = 626) were compared to non-users (n = 234) to determine whether there was an association between cannabis use and self-reported (a) pain level and (b) frequency of opioid use. Backward stepwise regression models were used.

RESULTS

A total of 860 participants was included in the analysis. Overall, 75% of the study sample reported pain as their primary medical symptom, and 67% of cannabis users reported having a disability. The mean difference in pain level between cannabis users and non-users was 4.5 units (on a 100-point scale) higher among cannabis users than non-users (p = 0.03); and cannabis use was statistically associated with pain level. High-frequency opioid users had lower odds of reporting cannabis use within the past year than low/no opioid users.

CONCLUSIONS

Although there was a statistical association between cannabis use and pain, the difference of 4.5 points in pain level between users and non-users was too small to reflect a clinically meaningful relative difference. This study may provide useful information to providers and clinicians about how the OAPP and similar programs may reduce opioid use and improve health outcomes.

Medical cannabis and its efficacy/effectiveness on the management of osteoarthritis pain and function

OBJECTIVE

Despite pharmacological treatments for osteoarthritis (OA), more individuals are choosing medical cannabis for OA symptom management and for mitigating opioid prescriptions for OA. This systematic review examines the global evidence of medical cannabis use on OA pain and function.

METHODS

The search was completed in MEDLINE (PubMed), Embase, and CINAHL within the past 10 years (2012-2022). We limited the search to English language articles. We did not include grey literature or case studies. Participant demographics included all adult individuals with OA who were using medical cannabis for OA. Study quality and risk of bias were evaluated using the Grading of Recommendations, Assessment, Development and Evaluations framework; and the Risk of Bias in Non-randomized Studies of Interventions tool. We used a narrative synthesis approach.

RESULTS

Overall, 7 studies were included: 2 randomized controlled trials (RCT) and 5 observational studies. Only 1 of the 2 RCTs reported improvements in pain for cannabis users. All 5 observational studies reported an improvement in pain levels, reduction of opioid use, and/or improvement in overall OA function. Despite high risk of bias ratings and low study quality, the consensus across studies was that medical cannabis use was effective for a subgroup of individuals suffering from OA pain.

CONCLUSIONS

There is low quality evidence to support medical cannabis use as a substitute for primary pharmacological treatment of OA. However, this does not negate the observations that medical cannabis may provide therapeutic relief for a subset of patients.

SYSTEMATIC REVIEW PROPSERO REGISTRATION

CRD42022354026.

The Impact of Chronic Cannabis Use on Esophageal Motility in Patients Referred for Esophageal Manometry

BACKGROUND

Tetrahydrocannabinol, the main psychoactive compound in cannabis, binds with high affinity to the cannabinoid 1 receptor. Small randomized controlled studies using conventional manometry have shown that the cannabinoid 1 receptor can modulate esophageal function, namely transient lower esophageal sphincter relaxation frequency and lower esophageal sphincter tone. The effect of cannabinoids on esophageal motility in patients referred for esophageal manometry has not been fully elucidated using high-resolution esophageal manometry (HREM). We aimed to characterize the clinical effect of chronic cannabis use on esophageal motility utilizing HREM.

METHODS

Patients who underwent HREM from 2009 to 2019 were identified at 4 academic medical centers. The study group consisted of patients with a noted history of chronic cannabis use, a diagnosis of cannabis-related disorder, or a positive urine toxicology screen. Age and gender-matched patients with no history of cannabis use were selected to form the control group. Data on HREM metrics based on the Chicago classification V3, and the prevalence of esophageal motility disorders were compared. Confounding effects of BMI and medications on esophageal motility were adjusted for.

RESULTS

Chronic cannabis use was found to be an independent negative predictor of weak swallows (β=-8.02, P =0.0109), but not a predictor of failed swallows ( P =0.6890). The prevalence of ineffective esophageal motility was significantly lower in chronic cannabis users compared with nonusers (OR=0.44, 95% CI 0.19-0.93, P =0.0384). There was no significant difference in the prevalence of other esophageal motility disorders between the 2 cohorts. In patients with dysphagia as their primary indication for HREM, chronic cannabis use was found to be independently associated with increased median integrated relaxation pressure (β=6.638, P =0.0153) and increased mean lower esophageal sphincter resting pressure (β=10.38, P =0.0084).

CONCLUSIONS

Chronic cannabis use is associated with decreased weak swallows and reduced prevalence of ineffective esophageal motility in patients referred for esophageal manometry. In patients referred for dysphagia, chronic cannabis use is associated with increased integrated relaxation pressure and lower esophageal sphincter resting pressure, though not to levels above the normal range.

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

Objectives

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

Methods

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

Results

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

Conclusions

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

Cannabis Policy and Consumption: Taking into account Substitution Effects

Background: Previous studies examining the cannabis-alcohol substitution effect have found that medical cannabis policies may result in substituting the use of cannabis in place of alcohol use. Objectives: This study adds to the literature on cannabis-alcohol substitution by analyzing the effect of decriminalization, medicinal cannabis, and adult-use legalization cannabis policies (2002-2019) on cannabis and alcohol use and substance substitution for all 50 states and the District of Columbia (N=867). Results: Results support the notion that liberalized cannabis policies can increase the prevalence of cannabis use. An adult-use legalization specific analysis yielded findings suggesting a complex and heterogenous effect of such laws on cannabis-alcohol complementation. Conclusion: Given the lack of clarity and heterogenous effects of cannabis laws, policy makers should carefully take into consideration the benefits of medical cannabis laws, along with the risks of decriminalization and adult-use legalization.

Medical Cannabis Patients Report Improvements in Health Functioning and Reductions in Opiate Use

Purpose: Opioid use rates have dropped as North American patients gain access to medical cannabis, indicating a harm reduction role, yet health outcomes remain mostly unexplored. This study presents self-reported medical cannabis use, perceptions of health functioning, and changes in opioid pain medication use in Florida medical cannabis patients.Methods: Patients (n = 2,183) recruited from medical dispensaries across Florida completed a 66-item cross-sectional survey that included demographic, health, and medication usage items, along with items from the Medical Outcomes Survey (SF-36) to assess health functioning before and after cannabis initiation.Results: Most participants were between the ages of 20 and 70 years of age (95%), over 54% were female, 47% were employed, and most (85%) were white. Commonly reported ailment groups were Pain and Mental Health combined (47.92%), Mental Health (28.86%) or Pain (9.07%). Health domains of bodily pain, physical functioning, and social functioning improved while limitations due to physical and emotional problems were unchanged. Most patients rated medical cannabis as being important to their quality of life. Many (60.98%) reported using pain medications prior to medical cannabis, 93.36% of these reported a change in pain medication after medical cannabis. The majority of participants (79%) reported either cessation or reduction in pain medication use following initiation of medical cannabis and 11.47% described improved functioning.Conclusions: The findings suggest that some medical cannabis patients decreased opioid use without harming quality of life or health functioning, soon after the legalization of medical cannabis. The public health implications of medical cannabis as an alternative pain medication are discussed.

Medical Cannabis Use and Pain: An Experience Sampling Study

Background: Little research has tested associations of pain and MC use after long-term treatment and through methods that have external validity outside experimental settings. The study examined associations of pain, associated painful experiences, and long-term medical cannabis (MC) use in chronic pain (CP) patients using a naturalistic daily diary study that provided novel and externally valid data. Methods: Data were obtained from 78 MC users with CP three times daily over a 10-day period (n_observations = 1,688). Mixed-effects models were used to test the associations between MC use and momentary experiences of pain, affect, and fatigue. Results: Within persons, elevated experiences of pain intensity were associated with greater intention to use MC within the next hour. No evidence was found that the time lapse since last MC use was associated with pain levels, negative affect, or fatigue. Conclusions: The results imply that after long-term use, CP patients intend to use MC in response to pain experiences. Yet, they may not actually achieve the pain relief. More research is needed to examine whether continued MC use despite lack of pain relief is related to relief of other symptoms (e.g., dependence, withdrawal) or positive benefits (e.g., general sense of well-being) or tolerance.