Buccally Absorbed Cannabidiol Shows Significantly Superior Pain Control and Improved Satisfaction Immediately After Arthroscopic Rotator Cuff Repair: A Placebo-Controlled, Double-Blinded, Randomized Trial

Cannabinoids for Acute Pain Management: Approaches and Rationale

PURPOSE OF THE REVIEW

Acute pain management remains a challenge and postoperative pain is often undermanaged despite many available treatment options, also including cannabinoids.

RECENT FINDINGS

In the light of the opioid epidemic, there has been growing interest in alternative care bundles for pain management, including cannabinoids as potential treatment to decrease opioid prescribing. Despite the lack of solid evidence on the efficacy of cannabinoids, their use among patients with pain, including those using opioids, is currently increasing. This use is supported by data suggesting that cannabinoids could potentially contribute to a better pain management and to a reduction in opioid doses while maintaining effective analgesia with minimum side effects. The scientific basis for supporting the use of cannabis is extensive, although it does not necessarily translate into relevant clinical outcomes. The use of cannabinoids in acute pain did not always consistently show statistically significant results in improving acute pain. Large randomized, controlled trials evaluating diverse cannabis extracts are needed in different clinical pain populations to determine safety and efficacy.

Cannabidiol (CBD) Products for Pain: Ineffective, Expensive, and With Potential Harms

Cannabidiol (CBD) attracts considerable attention for promoting good health and treating various conditions, predominantly pain, often in breach of advertising rules. Examination of available CBD products in North America and Europe demonstrates that CBD content can vary from none to much more than advertised and that potentially harmful other chemicals are often included. Serious harm is associated with chemicals found in CBD products and reported in children, adults, and the elderly. A 2021 International Association for the Study of Pain task force examined the evidence for cannabinoids and pain but found no trials of CBD. Sixteen CBD randomized trials using pharmaceutical-supplied CBD or making preparations from such a source and with pain as an outcome have been published subsequently. The trials were conducted in 12 different pain states, using 3 oral, topical, and buccal/sublingual administration, with CBD doses between 6 and 1,600 mg, and durations of treatment between a single dose and 12 weeks. Fifteen of the 16 showed no benefit of CBD over placebo. Small clinical trials using verified CBD suggest the drug to be largely benign; while large-scale evidence of safety is lacking, there is growing evidence linking CBD to increased rates of serious adverse events and hepatotoxicity. In January 2023, the Food and Drug Administration (FDA) announced that a new regulatory pathway for CBD was needed. Consumers and health care providers should rely on evidence-based sources of information on CBD, not just advertisements. Current evidence is that CBD for pain is expensive, ineffective, and possibly harmful. PERSPECTIVE: There is no good reason for thinking that CBD relieves pain, but there are good reasons for doubting the contents of CBD products in terms of CBD content and purity.

Cannabinoids and endocannabinoids as therapeutics for nervous system disorders: preclinical models and clinical studies

Cannabinoids are lipophilic substances derived from Cannabis sativa that can exert a variety of effects in the human body. They have been studied in cellular and animal models as well as in human clinical trials for their therapeutic benefits in several human diseases. Some of these include central nervous system (CNS) diseases and dysfunctions such as forms of epilepsy, multiple sclerosis, Parkinson's disease, pain and neuropsychiatric disorders. In addition, the endogenously produced cannabinoid lipids, endocannabinoids, are critical for normal CNS function, and if controlled or modified, may represent an additional therapeutic avenue for CNS diseases. This review discusses in vitro cellular, ex vivo tissue and in vivo animal model studies on cannabinoids and their utility as therapeutics in multiple CNS pathologies. In addition, the review provides an overview on the use of cannabinoids in human clinical trials for a variety of CNS diseases. Cannabinoids and endocannabinoids hold promise for use as disease modifiers and therapeutic agents for the prevention or treatment of neurodegenerative diseases and neurological disorders.

The Association of Cannabis Use After Discharge From Surgery With Opioid Consumption and Patient-reported Outcomes

OBJECTIVE

To compare outcomes of patients using versus not using cannabis as a treatment for pain after discharge from surgery.

BACKGROUND

Cannabis is increasingly available and is often taken by patients to relieve pain. However, it is unclear whether cannabis use for pain after surgery impacts opioid consumption and postoperative outcomes.

METHODS

Using Michigan Surgical Quality Collaborative registry data at 69 hospitals, we analyzed a cohort of patients undergoing 16 procedure types between January 1, 2021, and October 31, 2021. The key exposure was cannabis use for pain after surgery. Outcomes included postdischarge opioid consumption (primary) and patient-reported outcomes of pain, satisfaction, quality of life, and regret to undergo surgery (secondary).

RESULTS

Of 11,314 included patients (58% females, mean age: 55.1 years), 581 (5.1%) reported using cannabis to treat pain after surgery. In adjusted models, patients who used cannabis consumed an additional 1.0 (95% CI: 0.4-1.5) opioid pills after surgery. Patients who used cannabis were more likely to report moderate-to-severe surgical site pain at 1 week (adjusted odds ratio: 1.7, 95% CIL 1.4-2.1) and 1 month (adjusted odds ratio: 2.1, 95% CI: 1.7-2.7) after surgery. Patients who used cannabis were less likely to endorse high satisfaction (72.1% vs 82.6%), best quality of life (46.7% vs 63.0%), and no regret (87.6% vs 92.7%) (all P < 0.001).

CONCLUSIONS

Patient-reported cannabis use, to treat postoperative pain, was associated with increased opioid consumption after discharge from surgery that was of clinically insignificant amounts, but worse pain and other postoperative patient-reported outcomes.

Cannabidiol for Postoperative Pain Control After Arthroscopic Rotator Cuff Repair Demonstrates No Deficits in Patient-Reported Outcomes Versus Placebo: 1-Year Follow-up of a Randomized Controlled Trial

Background

Cannabidiol (CBD) has been shown recently to positively affect patient pain and satisfaction immediately after arthroscopic rotator cuff repair (ARCR). However, it is unclear whether the addition of CBD to a perioperative regimen could affect postoperative outcomes.

Purpose

To evaluate patient-reported outcomes among patients who underwent ARCR and received buccally absorbed CBD or an identical placebo for early postoperative pain management at 1-year follow-up.

Study Design

Randomized controlled trial; Level of evidence, 2.

Methods

Eligible patients had previously participated in a multicenter, placebo-controlled, randomized, double-blinded trial that evaluated the analgesic effects of CBD in the immediate postoperative period after ARCR. The experimental group received 25 mg of CBD 3 times/day if <80 kg and 50 mg of CBD 3 times/day if >80 kg for 14 days, with the control group receiving an identical placebo. The following outcomes were assessed at minimum 1-year follow-up: visual analog scale (VAS) for pain, American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE), and patient satisfaction. The rates of achievement of the Patient Acceptable Symptom State (PASS) were compared based on ASES at latest follow-up. Continuous and categorical variables were compared with the Mann-Whitney U test and Fisher exact test, respectively.

Results

Follow-up was obtained from 83 of 99 patients (83.8%) who completed the original trial. There were no significant differences between the CBD and control groups with respect to age, sex, body mass index, rate of concomitant procedures, or number of anchors used intraoperatively. At 1-year follow-up, there were no significant differences between the CBD and control groups in VAS pain (0.8 vs 1.2, P = .38), ASES (93.0 vs 91.1, P = .71), SANE (87.6 vs 90.1, P = .24), or satisfaction (97.4 vs 95.4, P = .41). A majority of patients achieved the PASS (81.0% [CBD] vs 77.5% [control]; P = .79).

Conclusion

Perioperative use of CBD for pain control among patients undergoing ARCR did not result in any significant deficits in pain, satisfaction, or patient-reported outcomes at 1-year postoperatively compared with a placebo control group. These findings suggest that CBD can be considered in a postoperative multimodal pain management regimen without detrimental effects on outcome.

Registration

NCT04672252 (ClinicalTrials.gov identifier).

An Overview of Cannabidiol

Cannabidiol (CBD) is one of the most interesting constituents of cannabis, garnering significant attention in the medical community in recent years due to its proven benefit for reducing refractory seizures in pediatric patients. Recent legislative changes in the United States have made CBD readily available to the general public, with up to 14% of adults in the United States having tried it in 2019. CBD is used to manage a myriad of symptoms, including anxiety, pain, and sleep disturbances, although rigorous evidence for these indications is lacking. A significant advantage of CBD over the other more well-known cannabinoid delta-9-tetrahydroncannabinol (THC) is that CBD does not produce a "high." As patients increasingly self-report its use to manage their medical conditions, and as the opioid epidemic continues to drive the quest for alternative pain management approaches, the aims of this narrative review are to provide a broad overview of the discovery, pharmacology, and molecular targets of CBD, its purported and approved neurologic indications, evidence for its analgesic potential, regulatory implications for patients and providers, and future research needs.

Perceptions of Orthopaedic Sports Medicine Surgeons About Medical Cannabidiol Use: A Survey Study

INTRODUCTION

Multiple studies exist identifying cannabidiol (CBD) as an effective part of an orthopaedic patient's pain regimen; however, there is a paucity of studies elucidating orthopaedic surgeons' perception of the use and prescription of CBD in the medical setting. This study surveys orthopaedic sports medicine surgeons about their previous education on and current perceptions and usage of CBD in their medical practice.

METHODS

Between April 2023 and July 2023, orthopaedic sports medicine surgeons from across the country were surveyed. This survey was designed in hopes of identifying physician perceptions and current use of CBD as well as their previous education and training on its use.

RESULTS

Overall, 75 orthopaedic surgeons responded. More than three-fourths of responders had not received formal education on medical CBD use, nor did they have partners or colleagues who used CBD in their practice. More than half of all surgeons believed that there is a stigma associated with CBD use. A higher proportion of surgeons from CBD legal states recommended CBD to help patients control their pain (53.7% vs. 37.5%). Less than 15% of responders believed that CBD can adversely affect surgical outcomes. Finally, four-fifths of all responders believed that CBD is easy to legally access and affordable to buy by patients who desire it.

DISCUSSION

The relative novelty of CBD inclusion in medicine has led to a lack of early education and overall experience with its use among orthopaedic sports medicine surgeons. Still, surgeons believe that CBD is a safe and effective option to control pain. As surgeons continue to gain more familiarity and trust with CBD's medical uses over time, it has the potential to be a mainstay in orthopaedic multimodal pain regimens.

Oral cannabidiol (CBD) as add-on to paracetamol for painful chronic osteoarthritis of the knee: a randomized, double-blind, placebo-controlled clinical trial

Background

Painful knee osteoarthritis (KOA) is common, pharmacological treatment, however, is often hampered by limited tolerability. Cannabidiol, which preclinically showed anti-inflammatory, analgesic activity, could supplement established analgesics, but robust clinical trials are lacking. The aim of our study was to investigate the effects of oral high-dose CBD administered over 8 weeks on pain, function and patient global assessment as an add-on to continued paracetamol in chronic symptomatic KOA.

Methods

Prospective, randomized, placebo-controlled, double-blind, parallel-group study. Single center, Outpatient Clinic, Department of Special Anaesthesia and Pain Therapy at Medical University of Vienna, Austria. Eligibility criteria included: age: 18-98 years; painful KOA; score ≥5 on the pain subscale of the Western Ontario and McMasters Universities Osteoarthritis (WOMAC) Index; KOA confirmed by imaging. Participants were on continued dosage of paracetamol 3 g/d and randomly assigned by web-based software 1:1 to oral cannabidiol 600 mg/d (n = 43) or placebo (n = 43). Study period: 8 weeks. Primary outcome: Change in WOMAC pain subscale scores (0 = no pain, 10 = worst possible pain) from baseline to week 8 of treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT04607603. Trial is completed.

Findings

The trial was conducted from October 1, 2020 to March 29, 2022. 159 patients screened, 86 randomized. Among 86 participants (mean age, 62.8 [SD 20.3] years; 60 females [69.8%]), 58 (67.4%) completed the trial. Mean baseline WOMAC pain subscale was 6.0 ± 1.1. Analysis: Intention-to-treat principal. Mean reduction in WOMAC pain subscale was 2.5 (95% CI: 1.8-3.3) in the cannabidiol group and 2.4 (95% CI: 1.7-3.2) in the placebo group with no significant group difference (p = 0.80). Adverse events were significantly more frequent with cannabidiol (cannabidiol: 135 [56%]; placebo: 105 [44%]) (p = 0.008). Rise above baseline of liver aminotransferases and gamma-glutamyltransferase was significantly more common in the cannabidiol (n = 15) than the placebo group (n = 5) (p = 0.02).

Interpretation

In KOA patients, oral high-dose add-on cannabidiol had no additional analgesic effect compared to adding placebo to continued paracetamol. Our results do not support the use of cannabidiol as an analgesic supplement in KOA.

Funding

Trigal Pharma GmbH.

Perceptions and Opinions on Cannabidiol in the Orthopaedic Sports Medicine Community

Background

Cannabidiol (CBD) is a known pain modulator that is garnering increased attention in the orthopaedic world. There may be a considerable knowledge gap among orthopaedic sports medicine providers and their perception of its therapeutic value.

Purpose

To (1) examine the knowledge and beliefs of sports medicine orthopaedic providers with respect to CBD, (2) deliver an educational component, and (3) elucidate potential barriers to its widespread application.

Study Design

Cross-sectional study.

Methods

A 3-component, 25-question online survey was distributed to members of the American Orthopaedic Society for Sports Medicine and the Arthroscopy Association of North America between July and October 2022. The first 20 questions assessed baseline knowledge and opinions regarding CBD, followed by an educational component, and then 5 questions assessing whether the respondents' opinions had changed after learning more about CBD. Responses were compared according to age, practice setting, and state's cannabinoid legalization status using the chi-square test, and changes in opinions from before to after the educational component were compared using the paired t test.

Results

There were 101 survey responses, for a response rate of approximately 1%. Most respondents believed that there is a role for CBD in postoperative pain management (76%), acute pain and inflammation after an injury (62%), and chronic pain (94%). Most respondents admitted that they were not knowledgeable about the mechanism of action (89%) or their state's laws (66%) concerning CBD. A minority (25%) believed that CBD has psychoactive properties. While most respondents (76%) did not believe that they would be stigmatized if they were to suggest CBD to a patient, only 48% had ever suggested CBD. Notably, 94% of respondents had encountered patients who reported trying CBD to treat pain. After reading the fact sheet, 51% of respondents stated that their opinion on CBD had changed, and 63% felt inclined to investigate the topic further.

Conclusion

Most survey respondents believed that CBD has a role in postoperative and chronic pain management. Although there was a relative familiarity with CBD, there was a knowledge gap, suggesting that increased attention, education, and research are necessary.

Cannabis Use Disorder Not Associated With Opioid Analgesic Use or Patient-Reported Outcomes After ACL Reconstruction: A Retrospective Matched-Cohort Analysis

BACKGROUND

The purpose of this study was to compare opioid analgesic use and patient-reported outcomes (PROs) after anterior cruciate ligament reconstruction (ACLR) between patients with and without cannabis use disorder (CUD).

HYPOTHESIS

We hypothesized that patients with CUD would have greater postoperative opioid usage with comparable improvement in PROs.

STUDY DESIGN

Retrospective matched-cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

We identified patients with CUD who underwent primary ACLR at a single center and had minimum 3-month follow-up. Patients with CUD were propensity score matched 1:1 to non-CUD controls with respect to age, sex, and follow-up time. Total refills, days supply, and morphine milligram equivalents (MMEs) of opioid analgesics prescribed were calculated for up to 1 year postoperatively. Patient-Reported Outcome Information System (PROMIS) instruments were used to assess PROs. Opioid use and outcomes were compared between CUD and control groups using Mann-Whitney U test and Fisher's exact test. P values <0.05 were considered significant.

RESULTS

A total of 104 patients with CUD were matched to 104 controls. Both groups were majority male (65.4% male, 34.6% female). The CUD group had a mean age of 29.9 years and mean follow-up time of 16.1 months. There was no significant intergroup difference in opioid prescription rates (CUD 82.7% vs control 83.7%, P ≥ 0.99). Among patients prescribed opioids, there were no significant intergroup differences in total days supply (P = 0.67), total MMEs (P = 0.71), or MMEs per day (P = 0.65). There were no significant differences in pre- to postoperative improvement in PROMIS Pain Intensity (P = 0.51), Pain Interference (P = 0.81), Mobility (P = 0.90), Mental Health (P = 0.74), or Physical Health (P = 0.94).

CONCLUSION

There were no significant differences detected in opioid usage or PRO improvement after ACLR between patients with CUD and those without. However, because a sample size was not determined a priori, a larger sample may show a difference.

CLINICAL RELEVANCE

CUD does not appear to correlate with inferior outcomes after ACLR.

Cannabidiol inhibits Nav channels through two distinct binding sites

Cannabidiol (CBD), a major non-psychoactive phytocannabinoid in cannabis, is an effective treatment for some forms of epilepsy and pain. At high concentrations, CBD interacts with a huge variety of proteins, but which targets are most relevant for clinical actions is still unclear. Here we show that CBD interacts with Nav1.7 channels at sub-micromolar concentrations in a state-dependent manner. Electrophysiological experiments show that CBD binds to the inactivated state of Nav1.7 channels with a dissociation constant of about 50 nM. The cryo-EM structure of CBD bound to Nav1.7 channels reveals two distinct binding sites. One is in the IV-I fenestration near the upper pore. The other binding site is directly next to the inactivated "wedged" position of the Ile/Phe/Met (IFM) motif on the short linker between repeats III and IV, which mediates fast inactivation. Consistent with producing a direct stabilization of the inactivated state, mutating residues in this binding site greatly reduced state-dependent binding of CBD. The identification of this binding site may enable design of compounds with improved properties compared to CBD itself.

Update on Cannabidiol Clinical Toxicity and Adverse Effects: A Systematic Review

BACKGROUND

Compelling evidence from preclinical and clinical studies supports the therapeutic role of cannabidiol (CBD) in several medical disorders. We reviewed the scientific evidence on CBD-related toxicity and adverse events (AEs) in 2019, at the beginning of the spike in clinical studies involving CBD. However, CBD safety remained uncertain.

OBJECTIVE

With the benefit of hindsight, we aimed to provide an update on CBD-related toxicity and AEs in humans.

METHODS

A systematic literature search was conducted following PRISMA guidelines. PubMed, Cochrane, and Embase were accessed in October 2022 to identify clinical studies mentioning CBDrelated toxicity/AEs from February 2019 to September 2022. Study design, population characteristics, CBD doses, treatment duration, co-medications, and AEs were compiled.

RESULTS

A total of 51 reports were included. Most studies investigated CBD efficacy and safety in neurological conditions, such as treatment-resistant epilepsies, although a growing number of studies are focusing on specific psychopathological conditions, such as substance use disorders, chronic psychosis, and anxiety. Most studies report mild or moderate severity of AEs. The most common AEs are diarrhea, somnolence, sedation, and upper respiratory disturbances. Few serious AEs have been reported, especially when CBD is co-administered with other classes of drugs, such as clobazam and valproate.

CONCLUSION

Clinical data suggest that CBD is well tolerated and associated with few serious AEs at therapeutic doses both in children and adults. However, interactions with other medications should be monitored carefully. Additional data are needed to investigate CBD's long-term efficacy and safety, and CBD use in medical conditions other than epilepsy syndromes.