A Systematic Review With Meta-Analysis of the Efficacy of Cannabis and Cannabinoids for Inflammatory Bowel Disease: What Can We Learn From Randomized and Nonrandomized Studies?

Cannabinoids for Inflammatory Bowel Disease: A Scoping Review

Purpose: Inflammatory bowel disease (IBD) has two main variants, ulcerative colitis (UC) and Crohn's disease (CD), which are characterized by a cycle of remission and relapse. The aim of this scoping review is to understand the landscape of unprescribed and prescribed cannabis use among patients with IBD and investigate objective clinical benefits. Methodology: A literature search was performed across Medline, Embase via Ovid, Scopus, and Cochrane Library databases. We included 40 studies (14 abstracts/letters, 7 randomized controlled trials [RCTs], 6 cohort studies [2 case-matched], 10 cross-sectional surveys, and 3 meta-analyses) in the review. Results: Between 11% and 17.6% of surveyed patients used cannabis for symptom control with a lifetime prevalence of 39.8-78.2%. Patients reported reduced abdominal pain, emotional distress, stool frequency, and anorexia. There was a higher rate of depression, tobacco, and alcohol use among patients with IBD who used cannabis. Individual studies showed patients who were prescribed cannabis were more likely to have had surgery for IBD (14.5% vs. 4.7%, p = 0.0008), require future abdominal surgery (odds ratio = 5.03), report a lower quality of life (p = 0.0001), currently be on corticosteroids (18.1% vs. 10.4%, p = 0.04) and opioids (27.7% vs. 6.4%, p = 0.0001). RCTs of cannabinoids reported mild reductions in disease activity and variable endoscopic inflammation improvement. Conclusions: Patients who use cannabis for IBD are a cohort with refractory disease and lower quality of life who report improvements in symptom management. However, the ability to reduce underlying disease activity appears very modest. Further trials using refined cannabinoid formulations may define a use in IBD.

Systematic reviews and meta-analyses in regional anesthesia and pain medicine (Part II): guidelines for performing the systematic review

In Part I of this series, we provide guidance for preparing a systematic review protocol. In this article, we highlight important steps and supplement with exemplars on conducting and reporting the results of a systematic review. We suggest how authors can manage protocol violations, multiplicity of outcomes and analyses, and heterogeneity. The quality (certainty) of the evidence and strength of recommendations should follow the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. It is our goal that Part II of this series provides valid guidance to authors and peer reviewers who conduct systematic reviews to adhere to important constructs of transparency, structure, reproducibility, and accountability. This will likely result in more rigorous systematic reviews being submitted for publication to the journals like Regional Anesthesia & Pain Medicine and Anesthesia & Analgesia.

Narrative bias ("spin") is common in randomised trials and systematic reviews of cannabinoids for pain

ABSTRACT

We define narrative bias as a tendency to interpret information as part of a larger story or pattern, regardless of whether the facts support the full narrative. Narrative bias in title and abstract means that results reported in the title and abstract of an article are done so in a way that could distort their interpretation and mislead readers who had not read the whole article. Narrative bias is often referred to as "spin." It is prevalent in abstracts of scientific papers and is impactful because abstracts are often the only part of an article read. We found no extant narrative bias instrument suitable for exploring both efficacy and safety statements in randomized trials and systematic reviews of pain. We constructed a 6-point instrument with clear instructions and tested it on randomised trials and systematic reviews of cannabinoids and cannabis-based medicines for pain, with updated searches to April 2021. The instrument detected moderate or severe narrative bias in the title and abstract of 24% (8 of 34) of randomised controlled trials and 17% (11 of 64) of systematic reviews; narrative bias for efficacy and safety occurred equally. There was no significant or meaningful association between narrative bias and study characteristics in correlation or cluster analyses. Bias was always in favour of the experimental cannabinoid or cannabis-based medicine. Put simply, reading title and abstract only could give an incorrect impression of efficacy or safety in about 1 in 5 papers reporting on these products.

Cannabis Use in Patients With Inflammatory Bowel Disease Following Legalization of Cannabis in Canada

Background

Cannabis is used by patients with Crohn's disease (CD) and ulcerative colitis (UC) as an alternative to, or in combination with, conventional therapies to treat symptoms such as abdominal pain, poor sleep, and reduced appetite. The clinical efficacy of cannabis for these disorders is controversial, with some studies showing harmful outcomes associated with its use. Previous studies suggest that cannabis is used by ~12% of patients with UC and ~16% of patients with CD in the USA despite legal prohibition.

Methods

We conducted a prospective cohort study of adult patients with inflammatory bowel diseases (IBD) followed in a Canadian tertiary care center. Patients completed an online 40-question survey that included demographics, IBD disease history, cannabis use, and the Short Inflammatory Bowel Disease Questionnaire (SIBDQ).

Results

Completed surveys were obtained from 254 participants (148 with CD, 90 with UC, and 16 with indeterminate colitis). Recent cannabis use was reported by 41% of CD and 31% of UC participants. Interestingly, only 46% of participants who used cannabis discussed their use with their physician. Participants who recently used cannabis reported more abdominal pain, poor appetite, and flatulence, and importantly this was associated with lower SIBDQ scores (recent use 37 vs non-recent use 40).

Conclusions

Cannabis use among patients with IBD has more than doubled since its legalization. Cannabis use is associated with worse abdominal symptoms and quality of life. Physicians should inquire about cannabis use and optimize symptom control with evidence-based therapies.

Systematic Reviews and Meta-analyses in Regional Anesthesia and Pain Medicine (Part II): Guidelines for Performing the Systematic Review

In Part I of this series, we provide guidance for preparing a systematic review protocol. In this article, we highlight important steps and supplement with exemplars on conducting and reporting the results of a systematic review. We suggest how authors can manage protocol violations, multiplicity of outcomes and analyses, and heterogeneity. The quality (certainty) of the evidence and strength of recommendations should follow the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. It is our goal that Part II of this series provides valid guidance to authors and peer reviewers who conduct systematic reviews to adhere to important constructs of transparency, structure, reproducibility, and accountability. This will likely result in more rigorous systematic reviews being submitted for publication to the journals like Regional Anesthesia & Pain Medicine and Anesthesia & Analgesia .

Effect of cannabinoids in mild-to-moderate cases of Crohn's disease as compared to placebo: a systematic review and meta-analysis of randomised controlled trials

INTRODUCTION

In view of limited treatment options (those too may fail) for Crohn's disease, cannabinoids have been tried as a therapeutic. However, their efficacy is not unequivocally established. This systematic review and meta-analysis was planned to pool data from randomised controlled trials (RCTs) evaluating effect of cannabinoids in Crohn's disease with an intention to take this uncertainty away.

CONTENT

Following literature search in Medline, EMBASE, Scopus and Google Scholar databases, RCTs assessing the effect of cannabinoids on mild-to-moderate Crohn's disease in adults were included. Crohns' disease activity index (CDAI), QoL (Quality of life), number participants achieving full remission and serum CRP at eight weeks of treatment were the outcomes considered for meta-analysis. Quality of studies was assessed using Cochrane's RoB2 tool. Random effect model was applied for meta-analysis. Heterogeneity was assessed by Cochrane 'Q' statistics and I2 test. Sensitivity analysis was performed to identify the major contributor(s) to heterogeneity and assess robustness of the results.

SUMMARY

Risk of bias for the four included studies varied from 'low' to 'some concern'. Overall effect estimate (SMD -0.92; 95 % CI -1.80, -0.03) indicated a statistically significant effect of cannabinoids as compared to control (p<0.05) on CDAI score. Effect of cannabinoids on rest of the outcome parameters was comparable to that of placebo. Magnitude of heterogeneity for different outcome parameters ranged from 'low' to 'substantial'.

OUTLOOK

Cannabinoids were superior to placebo for favourably affecting the disease severity in terms of CDAI score. However, no statistically significant difference was found between the two for improving QoL, causing full disease-remission and reducing inflammatory markers. The results must be interpreted with caution in view of relatively high heterogeneity among the studies.

Factors influencing the quality of life in inflammatory bowel disease: A comprehensive review

Inflammatory bowel disease (IBD) is a group of chronic relapsing disorders, including Crohn's disease (CD) and ulcerative colitis (UC), which affects an increasing number of people worldwide. In the last few decades, the scientific world has witnessed many developments in IBD management by controlling debilitating symptoms and remaining in remission for more protracted periods. Even so, we still have a large population suffering from active IBD. An individual's quality of life (QoL) can be severely affected by IBD, like any other chronic illness. In this article, we have reviewed factors influencing the QoL in IBD patients, including chronic pain, diet, physical activity, and psychological factors like depression, anxiety, and stress symptoms. We also discussed the mechanisms of diet-microbial-immune system interaction, currently available dietary therapies for active CD and UC, and early psycho-social interventions that can reduce the disease burden and improve QoL in IBD patients.

Cannabinoids and the Gastrointestinal Tract

The synthesis and degradation of endocannabinoids, location of cannabinoid (CB) receptors, and cannabinoid mechanisms of action on immune/inflammatory, neuromuscular, and sensory functions in digestive organs are well documented. CB2 mechanisms are particularly relevant in immune and sensory functions. Increasing use of cannabinoids in the United States is impacted by social determinants of health including racial discrimination, which is associated with tobacco and cannabis co-use, and combined use disorders. Several conditions associated with emesis are related to cannabinoid use, including cannabinoid hyperemesis or withdrawal, cyclic vomiting syndrome, and nausea and vomiting of pregnancy. Cannabinoids generally inhibit gastrointestinal motor function; yet they relieve symptoms in patients with gastroparesis and diverse nausea syndromes. Cannabinoid effects on inflammatory mechanisms have shown promise in relatively small placebo-controlled studies in reducing disease activity and abdominal pain in patients with inflammatory bowel disease. Cannabinoids have been studied in disorders of motility, pain, and disorders of gut-brain interaction. The CB2-receptor agonist, cannabidiol, reduced the total Gastroparesis Cardinal Symptom Index and increases the ability to tolerate a meal in patients with gastroparesis appraised over 4 weeks of treatment. In contrast, predominant-pain end points in functional dyspepsia with normal gastric emptying were not improved significantly with cannabidiol. The CB2 agonist, olorinab, reduced abdominal pain in inflammatory bowel disease in an open-label trial and in constipation-predominant irritable bowel syndrome in a placebo-controlled trial. Cannabinoid mechanisms alter inflammation in pancreatic and liver diseases. In conclusion, cannabinoids, particularly agents affecting CB2 mechanisms, have potential for inflammatory, gastroparesis, and pain disorders; however, the trials require replication and further understanding of risk-benefit to enhance use of cannabinoids in gastrointestinal diseases.

Should gastroenterologists prescribe cannabis? The highs, the lows and the unknowns

Cannabis, commonly known as marijuana, is a drug extracted from the Cannabis plant known for its psychotropic and medicinal properties. It has been used for healing purposes during ancient times, although its psychoactive components led to its restricted use in medicine. Nonetheless, cannabis is found to have modulatory effects on the endocannabinoid system exhibiting its medicinal role in the gastrointestinal (GI) system. Emerging animal and human studies demonstrate the influential effects of cannabis on a variety of GI diseases including inflammatory bowel disease, motility disorders and GI malignancies. It also has a regulatory role in GI symptoms including nausea and vomiting, anorexia, weight gain, abdominal pain, among others. However, both its acute and chronic use can lead to undesirable side effects such as dependency and addiction, cognitive impairment and cannabinoid hyperemesis syndrome. We will discuss the role of cannabis in the GI system as well as dosing strategies to help guide gastroenterologists to assess its efficacy and provide patient counseling before prescription of medical marijuana.

Cannabis Use and Its Association With Thirty- and Ninety-Day Hospital Readmissions for Patients Admitted for an Inflammatory Bowel Disease Exacerbation

Background

Though viewed as a potentially safer palliative alternative to opioids, studies of cannabis use for inflammatory bowel disease (IBD) are limited. The impact of opioids on hospital readmissions for IBD has been extensively examined, but cannabis has not been similarly studied. Our goal was to examine the relationship between cannabis use and the risk of 30- and 90-day hospital readmissions.

Methods

We conducted a review of all adults admitted for an IBD exacerbation from January 1, 2016 to March 1, 2020 within the Northwell Health Care system. Patients with an IBD exacerbation were identified by primary or secondary ICD10 code (K50.xx or K51.xx) and administration of intravenous (IV) solumedrol and/or biologic therapy. Admission documents were reviewed for the terms "marijuana", "cannabis", "pot" and "CBD".

Results

A total of 1,021 patient admissions met inclusion criteria, of whom 484 (47.40%) had Crohn's disease (CD) and 542 (53.09%) were female. Pre-admission cannabis use was reported by 74 (7.25%) patients. Factors found to be associated with cannabis use included younger age, male gender, African American/Black race, current tobacco and former alcohol use, anxiety, and depression. Cannabis use was found to be associated with 30-day readmission among patients with ulcerative colitis (UC), but not among patients with CD, after respectively adjusting each final model by other factors (odds ratio (OR): 2.48, 95% confidence interval (CI): 1.06 - 5.79 and OR: 0.59, 95% CI: 0.22 - 1.62, respectively). Cannabis use was not found to be associated with 90-day readmission on univariable analysis (OR: 1.11, 95% CI: 0.65 - 1.87) nor in the final multivariable model after adjusting for other factors (OR: 1.19, 95% CI: 0.68 - 2.05).

Conclusion

Pre-admission cannabis use was found to be associated with 30-day readmission among patients with UC, but not with 30-day readmission for patients with CD nor with 90-day readmission, following an IBD exacerbation.

The effect of medical cannabis in inflammatory bowel disease: analysis from the UK Medical Cannabis Registry

OBJECTIVES

Cannabis-based medicinal products (CBMPs) have shown promising preclinical activity in inflammatory bowel disease (IBD). However, clinical trials have not demonstrated effects on inflammation. This study aims to analyze changes in health-related quality of life (HRQoL) and adverse events in IBD patients prescribed CBMPs.

METHODS

A case series from the UK Medical Cannabis Registry was performed. Primary outcomes included changes from baseline in the Short Inflammatory Bowel Disease Questionnaire (SIBDQ), Generalized Anxiety Disorder-7 (GAD-7), Single-Item Sleep Quality Scale (SQS), and EQ-5D-5L Index score at 1 and 3 months. Statistical significance was defined using p < 0.050.

RESULTS

Seventy-six patients with Crohn's disease (n = 51; 67.11%) and ulcerative colitis (n = 25; 32.89%) were included. The median baseline SIBDQ score improved at 1 and 3 months. EQ-5D-5L index values, GAD-7, and SQS also improved after 3 months (p < 0.050). Sixteen (21.05%) patients reported adverse events with the majority being classified as mild to moderate in severity.

CONCLUSION

Patients treated with CBMPs for refractory symptoms of Crohn's disease and ulcerative colitis demonstrated a short-term improvement in IBD-specific and general HRQoL. Prior cannabis consumers reported greater improvement compared to cannabis-naïve individuals.

Patient Perspectives on Medical Trauma Related to Inflammatory Bowel Disease

Post-traumatic stress symptoms (PTSS) in response to medical trauma are understudied in inflammatory bowel disease (IBD). Two studies identify surgery, hospitalizations, and disease severity as risk factors. We aimed to document IBD-related patient experiences and how these relate to PTSS via a qualitative study. Adult patients with confirmed IBD recruited from two gastroenterology clinics underwent a semi-structured interview with a psychologist and completed the Post Traumatic Stress Disorder Symptom Scale for DSM5 (PSSI-5). Interviews were analyzed using an interpretive phenomenological approach. Themes and subthemes with representative quotations were documented based on thematic saturation. 16 participants, five met PSSI-5 criteria for PTSD. Five themes emerged: disease uncertainty, information exchange/quality, medical procedures, surgery, and coping. Patients with IBD may experience medical PTSS from several sources. Information, communication, and trust in clinicians is vital but may be sub-optimal. Both adaptive and maladaptive coping strategies are used to mitigate PTSS.

Comorbid anxiety-like behavior in a rat model of colitis is mediated by an upregulation of corticolimbic fatty acid amide hydrolase

Peripheral inflammatory conditions, including those localized to the gastrointestinal tract, are highly comorbid with psychiatric disorders such as anxiety and depression. These behavioral symptoms are poorly managed by conventional treatments for inflammatory diseases and contribute to quality of life impairments. Peripheral inflammation is associated with sustained elevations in circulating glucocorticoid hormones, which can modulate central processes, including those involved in the regulation of emotional behavior. The endocannabinoid (eCB) system is exquisitely sensitive to these hormonal changes and is a significant regulator of emotional behavior. The impact of peripheral inflammation on central eCB function, and whether this is related to the development of these behavioral comorbidities remains to be determined. To examine this, we employed the trinitrobenzene sulfonic acid-induced model of colonic inflammation (colitis) in adult, male, Sprague Dawley rats to produce sustained peripheral inflammation. Colitis produced increases in behavioral measures of anxiety and elevations in circulating corticosterone. These alterations were accompanied by elevated hydrolytic activity of the enzyme fatty acid amide hydrolase (FAAH), which hydrolyzes the eCB anandamide (AEA), throughout multiple corticolimbic brain regions. This elevation of FAAH activity was associated with broad reductions in the content of AEA, whose decline was driven by central corticotropin releasing factor type 1 receptor signaling. Colitis-induced anxiety was reversed following acute central inhibition of FAAH, suggesting that the reductions in AEA produced by colitis contributed to the generation of anxiety. These data provide a novel perspective for the pharmacological management of psychiatric comorbidities of chronic inflammatory conditions through modulation of eCB signaling.

Immunomodulation by cannabinoids: Current uses, mechanisms, and identification of data gaps to be addressed for additional therapeutic application

The endocannabinoid system plays a critical role in immunity and therefore its components, including cannabinoid receptors 1 and 2 (CB₁ and CB₂), are putative druggable targets for immune-mediated diseases. Whether modulating endogenous cannabinoid levels or interacting with CB₁ or CB₂ receptors directly, cannabinoids or cannabinoid-based therapeutics (CBTs) show promise as anti-inflammatory or immune suppressive agents. Herein we provide an overview of cannabinoid effects in animals and humans that provide support for the use of CBTs in immune-mediated disease such as multiple sclerosis (MS), inflammatory bowel disease (IBD), asthma, arthritis, diabetes, human immunodeficiency virus (HIV), and HIV-associated neurocognitive disorder (HAND). This is not an exhaustive review of cannabinoid effects on immune responses, but rather provides: (1) key studies in which initial and/or novel observations were made in animal studies; (2) critical human studies including meta-analyses and randomized clinical trials (RCTs) in which CBTs have been assessed; and (3) evidence for the role of CB₁ or CB₂ receptors in immune-mediated diseases through genetic analyses of single nucleotide polymorphisms (SNPs) in the CNR1 and CNR2 genes that encode CB₁ or CB₂ receptors, respectively. Perhaps most importantly, we provide our view of data gaps that exist, which if addressed, would allow for more rigorous evaluation of the efficacy and risk to benefit ratio of the use of cannabinoids and/or CBTs for immune-mediated diseases.