Eluxadoline: A Review in Diarrhoea-Predominant Irritable Bowel Syndrome

An Open-Label Study to Evaluate the Effect of Eluxadoline on the Single-Dose Pharmacokinetics of Midazolam in Healthy Participants

Eluxadoline is a mixed μ-opioid, κ-opioid receptor agonist, and δ-opioid receptor antagonist, approved in the United States for adults with diarrhea-predominant irritable bowel syndrome. This phase 1, single-center, open-label, single-sequence study was conducted on 30 healthy participants to establish whether steady-state eluxadoline increases systemic exposure of the cytochrome P450 (CYP) 3A4 substrate midazolam. Participants received oral midazolam 4 mg on day 1 with a 7-day washout period. On days 8-16, oral eluxadoline 100 mg was administered twice daily. On day 15, midazolam 4 mg was coadministered with the eluxadoline 100-mg morning dose. Primary outcome measures were pharmacokinetic parameters of midazolam and 1-hydroxy-midazolam. The midazolam and 1-hydroxy-midazolam geometric mean ratios and 90%CIs for maximum plasma drug concentration were 99.0% (91.6-107.0) and 113.8% (104.9-123.5), respectively, and area under the plasma concentration-time curves were 90.5% (83.9-97.6) and 105.1% (99.8-110.7), respectively, demonstrating the 2 treatments were bioequivalent, and there was no clinically significant drug interaction. All treatment-emergent adverse events were treatment related, mild in intensity, with no serious adverse events. These results suggest that eluxadoline has no clinically significant effect on CYP3A4 activity and is, therefore, unlikely to affect the pharmacokinetics of other CYP3A4 substrates.

Critical roles of G protein-coupled receptors in regulating intestinal homeostasis and inflammatory bowel disease

G protein-coupled receptors (GPCRs) are a group of membrane proteins that mediate most of the physiological responses to various signaling molecules such as hormones, neurotransmitters, and environmental stimulants. Inflammatory bowel disease (IBD) is a chronic relapsing disorder of the gastrointestinal tract and presents a spectrum of heterogeneous disorders falling under two main clinical subtypes including Crohn's disease (CD) and ulcerative colitis (UC). The pathogenesis of IBD is multifactorial and is related to a genetically dysregulated mucosal immune response to environmental drivers, mainly microbiotas. Although many drugs, such as 5-aminosalicylic acid, glucocorticoids, immunosuppressants, and biological agents, have been approved for IBD treatment, none can cure IBD permanently. Emerging evidence indicates significant associations between GPCRs and the pathogenesis of IBD. Here, we provide an overview of the essential physiological functions and signaling pathways of GPCRs and their roles in mucosal immunity and IBD regulation.

Eluxadoline Versus Antispasmodics in the Treatment of Irritable Bowel Syndrome: An Adjusted Indirect Treatment Comparison Meta-analysis

Objective: Eluxadoline is a newly approved drug for irritable bowel syndrome (IBS), but it has rarely been compared with positive controls. We aimed to compare eluxadoline with antispasmodics in the treatment of IBS.

Methods: We searched the OVID Medline, Embase, and the Cochrane Central Register of Controlled Trials databases for randomized controlled trials (RCTs) comparing eluxadoline or antispasmodics with placebo. The search was conducted from 1 January 1980, to 1 September 2020, without any language restrictions. The primary efficacy outcome was the relief of abdominal pain, defined by a reduction of pain scores of at least 30% from baseline. The secondary efficacy outcome was the relief of global IBS symptoms, defined by a composite response of a decrease in abdominal pain and improvement in stool consistency on the same day for at least 50% of the days assessed. The data were pooled using a random-effects model. Outcome estimates were pooled by using Risk Ratios (RRs) and P-scores.

Results: Forty-two trials with 8,457 participants were included from 45 articles. Compared with placebo, each of drotaverine, pinaverium, alverine combined with simethicone (ACS) and eluxadoline 100 mg was highly effective in the relief of abdominal pain, with drotaverine [RR, 2.71 (95% CI, 1.70 to 4.32), P-score = 0.95] ranking first. Drotaverine, otilonium, cimetropium, pinaverium, and eluxadoline 100 mg had significantly high the relief of global IBS symptomss, for which drotaverine [RR, 2.45 (95% CI, 1.42 to 4.22), P-score = 0.95] was ranked first. No significant difference was found between these interventions. Pinaverium had a significantly higher the relief of global IBS symptoms than eluxadoline [RR, 1.72 (95% CI, 1.33 to 2.21)] on sensitivity analysis. However, no significant difference was found in the number of adverse events between each intervention and the placebo.

Conclusion: Our network meta-analysis showed that eluxadoline 100 mg was at least as effective as antispasmodics in relieving abdominal pain in IBS. But eluxadoline had more reported adverse events. Antispasmodics are still the first choice for the treatment of IBS.

Updates on the epidemiology, pathogenesis, diagnosis, and management of postinfectious irritable bowel syndrome

PURPOSE OF REVIEW

With its impact on quality of life and increasing awareness, postinfectious irritable bowel syndrome (PI-IBS) is now gaining attention as one of the major health problems commonly encountered in gastrointestinal practice. Literature investigating the various pathogenic mechanisms involved is rapidly emerging. The objective of the current review is to provide an update on recent evidence published in the past 2 years describing advances in our understanding of the epidemiology, pathogenesis, diagnosis, and treatment of PI-IBS.

RECENT FINDINGS

Significant proportion of research in the recent past was preclinical in nature. Epidemiological studies continue to highlight the risk of IBS after infection, with recent studies documenting postprotozoal effects. Advances in pathogenic mechanisms included clinical studies, which documented micro-RNA down-regulation and Peroxiredoxin-1 up-regulation in colonic mucosa of PI-IBS patients. Protease-activated receptor-2 (PAR-2) activation in PI-IBS mice models resulted in increase in epithelial permeability, mucosal inflammation, visceral hypersensitivity. Moxibustion and rifamycin reduced intestinal inflammation by inhibiting cytokine and chemokine release via different mechanisms. Miltefosine reduced mast cell degranulation and TRPV1 activation, thereby reducing visceral hypersensitivity.

SUMMARY

At present, generalization of limited diagnostic and therapeutic strategies across a heterogeneous prevalent patient population impedes the ability to provide effective personalized care in PI-IBS. Further development in pathogenesis discovery, diagnostic tool development are needed in order to design well tolerated and effective therapies that guide treatments based on distinct pathways of disease.

Irritable bowel syndrome: a review of the general aspects and the potential role of vitamin D

Irritable Bowel Syndrome (IBS) is a bowel disorder leading to symptoms such as abdominal pain, modifications in the motility and bowel habits, distention, bloating, and gas. Vitamin D (VD) may interfere in a plethora of cellular mechanisms, and act directly or indirectly in the regulation of the microbiome, the release of anti-microbial peptides, modulation of the immune system and inflammation processes; which in turn, may positively interfere with the altered gut function. The main purpose of this review was to survey studies involving the impacts of VD on IBS. Area covered: Eligible studies including the term VD and IBS were searched in the MEDLINE-PubMed and EMBASE (2009-2018). VD may act direct or indirectly in the regulation of the gut microbiome, immune response, and psychosocial factors that may be included in the list of IBS triggering factors. Expert opinion: Once VD plays an essential role in many processes associated with IBS, its deficiency may be associated with IBS, and the supplementation could help in the therapeutic approach for this condition. For these reasons, the understanding of the association of VD in IBS is indispensable for the development of new strategies that could improve the quality of life of the patient.

Effect of acupuncture combined with Astragalus injection on peripheral blood inflammatory factors in children with diarrhea-predominant irritable bowel syndrome

The objective of this article is to explore the clinical efficacy of acupuncture therapy of Traditional Chinese Medicine (TCM) combined with Astragalus injection in the treatment of children with diarrhea-predominant irritable bowel syndrome (IBS), and its effects on 5-hydroxytryptamine (5-HT), neuropeptide Y (NPY), and calcitonin gene-related peptide (CGRP) in peripheral blood. A total of 116 children with diarrhea-predominant IBS admitted to our hospital from January 2017 to January 2018 were randomly divided into two groups. The control group was treated with Astragalus injection, while the research group was treated with acupuncture therapy of TCM combined with Astragalus injection. The therapeutic effects, the concentrations of CGRP, NPY, and 5-HT in peripheral blood were compared between the two groups. The therapeutic efficacy of the study group was better than that of the control group ( P < 0.05). The concentrations of CGRP, NPY, and 5-HT in the peripheral blood of the study group were less than those of the control group ( P < 0.05). Acupuncture therapy of TCM combined with Astragalus injection has a satisfactory effect in the treatment of children with diarrhea-predominant IBS, which is worthy of more publicity and application in the clinic.

Rome Foundation Working Team Report on Post-Infection Irritable Bowel Syndrome

BACKGROUND & AIMS

The existence of postinfection irritable bowel syndrome (PI-IBS) has been substantiated by epidemiology studies conducted in diverse geographic and clinical settings. However, the available evidence has not been well summarized, and there is little guidance for diagnosis and treatment of PI-IBS. The ROME Foundation has produced a working team report to summarize the available evidence on the pathophysiology of PI-IBS and provide guidance for diagnosis and treatment, based on findings reported in the literature and clinical experience.

METHODS

The working team conducted an evidence-based review of publication databases for articles describing the clinical features (diagnosis), pathophysiology (intestinal sensorimotor function, microbiota, immune dysregulation, barrier dysfunction, enteroendocrine pathways, and genetics), and animal models of PI-IBS. We used a Delphi-based consensus system to create guidelines for management of PI-IBS and a developed treatment algorithm based on published findings and experiences of team members.

RESULTS

PI-IBS develops in about 10% of patients with infectious enteritis. Risk factors include female sex, younger age, psychological distress during or before acute gastroenteritis, and severity of the acute episode. The pathogenesis of PI-PBS appears to involve changes in the intestinal microbiome as well as epithelial, serotonergic, and immune system factors. However, these mechanisms are incompletely understood. There are no evidence-based, effective pharmacologic strategies for treatment of PI-IBS. We provide a consensus-based treatment algorithm, based on clinical presentation and potential disease mechanisms.

CONCLUSIONS

Based on a systematic review of the literature and team experience, we summarize the clinical features, pathophysiology (from animal models and human studies), and progression of PI-IBS. Based on these findings, we present an algorithm for diagnosis and treatment of PI-IBS based on team consensus. We also propose areas for future investigation.

Evaluation of Eluxadoline Effect on Cardiac Repolarization

This study evaluated the effects of eluxadoline, a mixed μ‐opioid receptor (OR) and κ‐OR agonist and δ‐OR antagonist, on cardiac repolarization. This evaluator‐blinded, placebo‐ and positive‐controlled, 4‐period crossover study randomized healthy men and women to single oral doses of eluxadoline (therapeutic dose 100 mg or supratherapeutic dose 1000 mg), moxifloxacin 400 mg, or placebo. QT data were corrected using individual custom correction (QTcI). The primary endpoint was the change from baseline in QTcI intervals (ΔQTcI) between eluxadoline and placebo (ΔΔQTcI). An upper bound of the 95% confidence interval around ΔΔQTcI of 10 milliseconds was considered clinically significant. Concentration–QTc data were analyzed using a repeated‐measures, mixed‐effects linear model. Sixty‐four volunteers were treated, and 58 completed the study. Assay sensitivity was demonstrated with moxifloxacin (noted by ΔΔQTcI of 11.94 milliseconds). The maximum ΔΔQTcI for eluxadoline 1000 mg was 4.10 milliseconds 1 hour postdose (1‐sided 95% upper confidence bound, 5.81 milliseconds), and for eluxadoline 100 mg was 1.20 milliseconds at 0.5 hours postdose (1‐sided 95% upper confidence bound, 2.91 milliseconds). Primary ΔΔQTcI results were confirmed using Fridericia's formula for QTc. Categorical, morphological, and concentration–QTc analyses were consistent with the primary and secondary findings. There were no significant gender effects on ΔΔQTcI values. The most common adverse events were contact dermatitis and nausea (12.5% each) and dizziness (10.9%); adverse events were more frequent in the eluxadoline 1000 mg group. In conclusion, eluxadoline, at therapeutic or supratherapeutic doses, did not significantly prolong QT intervals, and was safe and generally well tolerated in this study population.

A Comprehensive Look at Irritable Bowel Syndrome and its Associated Factors Considering the Rome IV Criteria: A Penalized Smoothly Clipped Absolute Deviation Regression Approach in the Pars Cohort Study

BACKGROUND

After the introduction of the Rome IV criteria for the diagnosis of irritable bowel syndrome (IBS), studies on the clinical significance of the new criteria in the settings of a large study has been scarce.

Objective: Herein we used the infrastructures provided by one the largest cohort studies in Iran to evaluate the epidemiological features related to IBS.

METHODS

A total of 9264 participants, were enrolled in the initial registry. Diagnosis of IBS was done using the Rome IV criteria. Individuals with IBS were compared with a control group. Since the study included a large sample size of patients, we used the penalized smoothly clipped absolute deviation (SCAD) regression analysis to construct a model for the evaluation of factors associated with IBS.

RESULTS

Overall, data of 9163 participants entered the final analysis. In total, 1067 (11.6%) individuals were diagnosed with IBS, among which 57 (5.3%) were diarrhea dominant (IBS-D), 380 (35.6%) were constipation dominant (IBS-C), and 630 (59%) did not mention having any of the two (IBS-U). In the regression model, back pain/arthralgia (OR: 1.98, 95% CI: 1.65 - 2.40), insomnia (OR: 1.65, 95% CI: 1.40 - 1.93), depression (OR: 1.64, 95% CI: 1.38 - 1.95), female sex (OR: 1.58, 95% CI: 1.27 - 1.96), anxiety (OR: 1.43, 95% CI: 1.21 - 1.69), and being married (OR: 1.23, 95% CI: 1.03 - 1.48), were associated with higher rates of IBS. We found that IBS prevalence displays a peak at the age of 41 years for both men and women.

CONCLUSION

The present study provides a background for follow-up studies to be conducted in order to evaluate causality between IBS and some major diseases such as liver disease. We also found that opium use, although not statistically significant, in addition to sex, education, back/joint pain, depression, insomnia, anxiety, and marital status might be a contributing factor in IBS.

Cannabinoid Receptors and the Endocannabinoid System: Signaling and Function in the Central Nervous System

The biological effects of cannabinoids, the major constituents of the ancient medicinal plant Cannabis sativa (marijuana) are mediated by two members of the G-protein coupled receptor family, cannabinoid receptors 1 (CB1R) and 2. The CB1R is the prominent subtype in the central nervous system (CNS) and has drawn great attention as a potential therapeutic avenue in several pathological conditions, including neuropsychological disorders and neurodegenerative diseases. Furthermore, cannabinoids also modulate signal transduction pathways and exert profound effects at peripheral sites. Although cannabinoids have therapeutic potential, their psychoactive effects have largely limited their use in clinical practice. In this review, we briefly summarized our knowledge of cannabinoids and the endocannabinoid system, focusing on the CB1R and the CNS, with emphasis on recent breakthroughs in the field. We aim to define several potential roles of cannabinoid receptors in the modulation of signaling pathways and in association with several pathophysiological conditions. We believe that the therapeutic significance of cannabinoids is masked by the adverse effects and here alternative strategies are discussed to take therapeutic advantage of cannabinoids.

Spotlight on eluxadoline for the treatment of patients with irritable bowel syndrome with diarrhea

BACKGROUND

Irritable bowel syndrome with diarrhea (IBS-D) has limited options for treatment currently, including mainly anti-motility medications, antispasmodics, and antidepressants. This review discusses the properties of a new drug, eluxadoline, a gut-targeting mu- and kappa-opioid receptor agonist and a delta-opioid receptor antagonist, and its efficacy and safety in patients with IBS-D.

MATERIALS AND METHODS

A systematic review of the literature was undertaken to identify studies that had investigated eluxadoline as a treatment in IBS-D. A narrative review of other information is provided with respect to pharmacological and chemical properties. Where suitable, meta-analysis was performed with a random-effects model to produce a pooled estimate.

RESULTS

Eluxadoline showed efficacy improving stool consistency (standardized mean difference [SMD]: -0.29 at 12 weeks, p = 0.0004; -0.46 at 26 weeks, p = 0.0001), global symptoms (SMD: -0.15 at 12 weeks, p = 0.006; -0.14 at 26 weeks, p = 0.02), quality of life (SMD: 0.21 at 12 weeks, p < 0.0001; 0.16 at 26 weeks, p = 0.007), pain (SMD: -0.17 at 12 weeks, p = 0.001; -0.16 at 26 weeks, p = 0.01), and adequate relief (odds ratio [OR]: 1.99 at 12 weeks, p < 0.00001; 1.78 at 26 weeks, p < 0.0001). It also improved IBS severity and other abdominal symptoms such as bloating, discomfort, and risk of urgency and fecal incontinence. Its main side effects included constipation (OR: 3.49, p < 0.00001), vomiting (OR: 3.42, p = 0.0002), abdominal pain (OR: 1.78, p = 0.007), and nausea (OR: 1.42, p = 0.07). The overall quality of trials was satisfactory with the meta-analyses providing largely homogeneous outcomes.

CONCLUSION

Eluxadoline's place in clinical practice might prove useful since the pharmacological options of IBS-D are limited and eluxadoline showed a positive effect in treating the symptoms of IBS-D.

Mu-Opioid receptor biased ligands: A safer and painless discovery of analgesics?

Biased activation of G-protein-coupled receptors (GPCRs) is shifting drug discovery efforts and appears promising for the development of safer drugs. The most effective analgesics to treat acute pain are agonists of the μ opioid receptor (μ-OR), a member of the GPCR superfamily. However, the analgesic use of opioid drugs, such as morphine, is hindered by adverse effects. Only a few μ-OR agonists have been reported to selectively activate the G_i over β-arrestin signaling pathway, resulting in lower gastrointestinal dysfunction and respiratory suppression. Here, we discuss the strategies that led to the development of biased μ-OR agonists, and potential areas for improvement, with an emphasis on structural aspects of the ligand-receptor recognition process.