Effect of nortriptyline on symptoms of idiopathic gastroparesis: the NORIG randomized clinical trial

Benefits of Prokinetics, Gastroparesis Diet, or Neuromodulators Alone or in Combination for Symptoms of Gastroparesis

BACKGROUND & AIMS

Prokinetics have limited effectiveness for treating symptoms of gastroparesis. Thus, alternative or adjunct therapies, such as gastroparesis diets or neuromodulators, are often prescribed. Their therapeutic benefits alone or in combination remain unclear.

METHODS

One hundred and twenty-nine patients with symptoms of gastroparesis underwent wireless motility capsule gastric emptying time and gastric emptying scintigraphy. Based on test results, changes in therapy were recommended. Changes in Gastroparesis Cardinal Symptom Index (GCSI) and individual symptom scores over 6 months were related to recommendations for prokinetics, gastroparesis diet, or neuromodulators given as solo new therapies or in dual combinations. Multivariate analyses were performed to adjust for gastric emptying and other variables.

RESULTS

In the whole group regardless of therapy, GCSI scores decreased by 0.53 points (interquartile range, -1.25 to 0.05; P < .0001) over 6 months. GCSI did not decrease for prokinetics as solo new therapy (P = .95). Conversely, neuromodulators as solo therapy decreased GCSI scores (P = .04) and all individual symptoms except nausea/vomiting (P = .86). Prokinetics combined with gastroparesis diets or neuromodulators improved GCSI scores (P ≤ .04) and most individual symptoms. Adjusting for gastric emptying time on multivariate analyses showed greater GCSI decreases for nondelayed emptying for neuromodulators as solo new therapy (P = .01). Gastric emptying scintigraphy, gender, diabetes, and functional dyspepsia did not influence responses to any treatment.

CONCLUSIONS

Initiating prokinetics as solo new therapy had little benefit for patients with symptoms of gastroparesis. Neuromodulators as the only new therapy decreased symptoms other than nausea and vomiting, especially with nondelayed gastric emptying. Adding gastroparesis diets or neuromodulators to prokinetics offered relief, suggesting that combination therapies may be more useful in managing these patients. (ClinicalTrials.gov NCT02022826.).

A global bibliometric and visualized analysis of the status and trends of gastroparesis research

BACKGROUND

Gastroparesis has a substantial impact on the quality of life but has limited treatment options, which makes it a public health concern. No bibliometric studies on gastroparesis have been published thus far. Thus, this article aims to summarize and analyze research hotspots to provide a reference for clinical researchers.

MATERIALS AND METHODS

Gastroparesis-related research articles were searched in the Web of Science Core Collection (WOSCC), and relevant information was extracted after screening. A total of 1033 documents were analyzed with the bibliometric method using Microsoft Excel, Citespace, and VOSviewer.

RESULTS

Overall, our search retrieved 1033 papers contributed by 966 research institutions from 53 countries. Since 1980, publications in this field have increased rapidly. United States (n = 645) and Temple University (n = 122) were the most productive country and institution, respectively. Parkman, with 96 publications, was the most prominent author.

CONCLUSIONS

Research hotspots in gastroparesis can be summarized into four domains: innovation in diagnostic modalities, change of oral therapeutic agents, choice of surgical interventions, and pathological mechanisms. Future research on gastroparesis should focus on the quality of life of patients, diagnostic techniques, pyloromyotomy, and transpyloric stent placement.

Trends in Gastroparesis Management: A United States Population-based Study From 2010 to 2020

BACKGROUND

There is little consensus on the medical management of gastroparesis, a disorder characterized by delayed gastric emptying with symptoms of early satiety, nausea, vomiting, and upper abdominal pain.

GOALS

We utilized population-level data to: (1) describe the prevalence of different pharmacological and nonpharmacological therapies in patients with gastroparesis; and (2) trend the prevalence of these therapies from 2010 to 2020.

STUDY

More than 59 million unique medical records across 26 US-based major health care systems were surveyed using the Explorys platform to identify a cohort of adults with gastroparesis who completed both a gastric emptying study and upper endoscopy or upper gastrointestinal tract imaging. Prevalence of antiemetic, prokinetic, neuromodulator prescriptions, and surgical therapies for gastroparesis were searched within this cohort and trended annually from 2010 to 2020.

RESULTS

Antiemetics (72% of patients), prokinetics (47%), and neuromodulators (75% of patients, 44% of patients without a concomitant psychiatric or diabetic peripheral neuropathy diagnosis) were all commonly used in the treatment of patients with gastroparesis. From 2010 to 2020, there was an increase in the prevalence of antiemetic and neuromodulator prescriptions (36.4% to 57.6%, P <0.001 and 47.0% to 66.9%, P <0.001, respectively), whereas the prevalence of prokinetics remained relatively constant (31.8% to 31.6%, P =0.52). Procedural and surgical treatments were used in 5% of gastroparesis patients.

CONCLUSIONS

Treatments for gastroparesis have changed over the last decade: antiemetic and neuromodulator use has increased whereas prokinetic use has remained constant. This practice pattern may reflect the growing number and availability of antiemetics and neuromodulators and the small number and known side effects of prokinetics.

Gastroparesis: Myths, Misconceptions, and Management

Gastroparesis (GP), a historically vexing disorder characterized by symptoms of nausea, vomiting, abdominal pain, early satiety, and/or bloating, in the setting of an objective delay in gastric emptying, is often difficult to treat and carries a tremendous burden on the quality of patients' lives, as well as the healthcare system in general. Though the etiology of GP has been fairly well defined, much work has been done recently to better understand the pathophysiology of GP, as well as to identify novel effective and safe treatment options. As our understanding of GP has evolved, many myths and misconceptions still abound in this rapidly changing field. The goal of this review is to identify myths and misconceptions regarding the etiology, pathophysiology, diagnosis, and treatment of GP, in the context of the latest research findings which have shaped our current understanding of GP. Recognition and dispelling of such myths and misconceptions is critical to moving the field forward and ultimately advancing the clinical management of what will hopefully become a better understood and more manageable disorder in the future.

Antidepressants for pain management in adults with chronic pain: a network meta-analysis

BACKGROUND

Chronic pain is common in adults, and often has a detrimental impact upon physical ability, well-being, and quality of life. Previous reviews have shown that certain antidepressants may be effective in reducing pain with some benefit in improving patients' global impression of change for certain chronic pain conditions. However, there has not been a network meta-analysis (NMA) examining all antidepressants across all chronic pain conditions.

OBJECTIVES

To assess the comparative efficacy and safety of antidepressants for adults with chronic pain (except headache).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, AMED and PsycINFO databases, and clinical trials registries, for randomised controlled trials (RCTs) of antidepressants for chronic pain conditions in January 2022.

SELECTION CRITERIA

We included RCTs that examined antidepressants for chronic pain against any comparator. If the comparator was placebo, another medication, another antidepressant, or the same antidepressant at different doses, then we required the study to be double-blind. We included RCTs with active comparators that were unable to be double-blinded (e.g. psychotherapy) but rated them as high risk of bias. We excluded RCTs where the follow-up was less than two weeks and those with fewer than 10 participants in each arm.  DATA COLLECTION AND ANALYSIS: Two review authors separately screened, data extracted, and judged risk of bias. We synthesised the data using Bayesian NMA and pairwise meta-analyses for each outcome and ranked the antidepressants in terms of their effectiveness using the surface under the cumulative ranking curve (SUCRA). We primarily used Confidence in Meta-Analysis (CINeMA) and Risk of Bias due to Missing Evidence in Network meta-analysis (ROB-MEN) to assess the certainty of the evidence. Where it was not possible to use CINeMA and ROB-MEN due to the complexity of the networks, we used GRADE to assess the certainty of the evidence. Our primary outcomes were substantial (50%) pain relief, pain intensity, mood, and adverse events. Our secondary outcomes were moderate pain relief (30%), physical function, sleep, quality of life, Patient Global Impression of Change (PGIC), serious adverse events, and withdrawal.

MAIN RESULTS

This review and NMA included 176 studies with a total of 28,664 participants. The majority of studies were placebo-controlled (83), and parallel-armed (141). The most common pain conditions examined were fibromyalgia (59 studies); neuropathic pain (49 studies) and musculoskeletal pain (40 studies). The average length of RCTs was 10 weeks. Seven studies provided no useable data and were omitted from the NMA. The majority of studies measured short-term outcomes only and excluded people with low mood and other mental health conditions. Across efficacy outcomes, duloxetine was consistently the highest-ranked antidepressant with moderate- to high-certainty evidence. In duloxetine studies, standard dose was equally efficacious as high dose for the majority of outcomes. Milnacipran was often ranked as the next most efficacious antidepressant, although the certainty of evidence was lower than that of duloxetine. There was insufficient evidence to draw robust conclusions for the efficacy and safety of any other antidepressant for chronic pain.  Primary efficacy outcomes Duloxetine standard dose (60 mg) showed a small to moderate effect for substantial pain relief (odds ratio (OR) 1.91, 95% confidence interval (CI) 1.69 to 2.17; 16 studies, 4490 participants; moderate-certainty evidence) and continuous pain intensity (standardised mean difference (SMD) -0.31, 95% CI -0.39 to -0.24; 18 studies, 4959 participants; moderate-certainty evidence). For pain intensity, milnacipran standard dose (100 mg) also showed a small effect (SMD -0.22, 95% CI -0.39 to 0.06; 4 studies, 1866 participants; moderate-certainty evidence). Mirtazapine (30 mg) had a moderate effect on mood (SMD -0.5, 95% CI -0.78 to -0.22; 1 study, 406 participants; low-certainty evidence), while duloxetine showed a small effect (SMD -0.16, 95% CI -0.22 to -0.1; 26 studies, 7952 participants; moderate-certainty evidence); however it is important to note that most studies excluded participants with mental health conditions, and so average anxiety and depression scores tended to be in the 'normal' or 'subclinical' ranges at baseline already. Secondary efficacy outcomes Across all secondary efficacy outcomes (moderate pain relief, physical function, sleep, quality of life, and PGIC), duloxetine and milnacipran were the highest-ranked antidepressants with moderate-certainty evidence, although effects were small. For both duloxetine and milnacipran, standard doses were as efficacious as high doses. Safety There was very low-certainty evidence for all safety outcomes (adverse events, serious adverse events, and withdrawal) across all antidepressants. We cannot draw any reliable conclusions from the NMAs for these outcomes.

AUTHORS' CONCLUSIONS

Our review and NMAs show that despite studies investigating 25 different antidepressants, the only antidepressant we are certain about for the treatment of chronic pain is duloxetine. Duloxetine was moderately efficacious across all outcomes at standard dose. There is also promising evidence for milnacipran, although further high-quality research is needed to be confident in these conclusions. Evidence for all other antidepressants was low certainty. As RCTs excluded people with low mood, we were unable to establish the effects of antidepressants for people with chronic pain and depression. There is currently no reliable evidence for the long-term efficacy of any antidepressant, and no reliable evidence for the safety of antidepressants for chronic pain at any time point.

A randomized, double-blind, placebo-controlled, phase 2b study of the efficacy and safety of velusetrag in subjects with diabetic or idiopathic gastroparesis

BACKGROUND

This study assessed the efficacy and safety of velusetrag-a 5-HT₄ agonist with pan-gastrointestinal prokinetic activity-for gastroparesis symptom management and gastric emptying (GE).

METHODS

In this multicenter, double-blind, randomized, placebo-controlled study, subjects with diabetic or idiopathic gastroparesis received velusetrag 5, 15, or 30 mg or placebo for 12 weeks. The primary efficacy outcome was a 7-day mean Gastroparesis Cardinal Symptom Index 24-h composite score (GCSI-24H) change from baseline at week 4; GE was evaluated using scintigraphy (GES) and breath tests, and safety from adverse events (AEs).

KEY RESULTS

232 subjects (183 females; 113 idiopathic gastroparesis) received treatment from February 2015 through June 2017. Least-squares mean improvement from baseline GCSI-24H (primary endpoint) at week 4 was -1.5 following velusetrag 5 mg vs -1.1 following placebo (treatment difference, -0.4; 95% confidence interval, -0.75 to -0.03; nominal p = 0.0327; Hochberg-adjusted p = 0.0980 [not significant]). Symptom improvement from baseline was achieved only with velusetrag 5 mg, which resulted in greater improvement from baseline vs placebo in all gastroparesis core symptoms, especially in subjects with idiopathic gastroparesis. Improvement from baseline GE by GES was greater in subjects receiving velusetrag (all doses) vs placebo; >70% of subjects receiving velusetrag 30 mg had GE normalization at 4 h. Treatment-emergent AEs were generally mild.

CONCLUSIONS AND INFERENCES

Velusetrag treatment was generally well-tolerated and associated with improved GE vs placebo in subjects with diabetic or idiopathic gastroparesis; however, only the lowest dose, velusetrag 5 mg, was associated with short-term improvement in gastroparesis symptoms.

CLINICALTRIALS

GOV: NCT02267525.

Efficacy and Safety of Drugs for Gastroparesis: Systematic Review and Network Meta-analysis

BACKGROUND & AIMS

Although there have been multiple drugs tested in gastroparesis, their relative efficacy and safety are unknown. We evaluated this in a network meta-analysis of randomized controlled trials (RCTs).

METHODS

We searched the literature to September 7, 2022. We judged the efficacy of drugs based on global symptoms of gastroparesis; individual symptoms, including nausea, vomiting, abdominal pain, bloating, or fullness; and safety according to total adverse events and adverse events leading to withdrawal. We extracted data as intention-to-treat analyses, assuming dropouts to be treatment failures and reporting pooled relative risks (RRs) of not improving with 95% confidence intervals (CIs), ranking drugs according to P-score.

RESULTS

We identified 29 RCTs (3772 patients). Based on global symptoms, clebopride ranked first for efficacy (RR, 0.30; 95% CI, 0.16-0.57; P-score = .99) followed by domperidone (RR, 0.68; 95% CI, 0.48-0.98; P-score = .76). No other drug was superior to placebo. Only 2 drug classes were efficacious: in rank order, oral dopamine antagonists (RR, 0.58; 95% CI, 0.44-0.77; P-score = .96) and tachykinin-1 antagonists (RR, 0.69; 95% CI, 0.52-0.93; P-score = .83). For individual symptoms, oral metoclopramide ranked first for nausea (RR 0.46; 95% CI, 0.21-1.00; P-score = .95), fullness (RR 0.67; 95% CI, 0.35-1.28; P-score = .86), and bloating (RR 0.53; 95% CI, 0.30-0.93; P-score = .97), based on only 1 small trial. Only prucalopride was more likely to be associated with adverse events than placebo.

CONCLUSIONS

In a network meta-analysis, oral dopamine antagonists and tachykinin-1 antagonists were more efficacious than placebo for gastroparesis, but confidence in the evidence was low to moderate for most comparisons. There is an unmet need for efficacious therapies for gastroparesis.

2023 update on the clinical management of gastroparesis

INTRODUCTION

Gastroparesis is characterized by symptoms suggesting gastric retention of food and objective evidence of delayed gastric emptying in the absence of a mechanical obstruction. Nausea, vomiting, early satiety, and postprandial fullness are the classic symptoms of gastroparesis. Gastroparesis is increasingly encountered by physicians. There are several recognized etiologies of gastroparesis, including diabetic, post-surgical, medication-induced, post-viral, and idiopathic.

AREAS COVERED

A comprehensive literature review was conducted to identify studies discussing gastroparesis management. Dietary modifications, medication adjustments, glucose control, antiemetic agents, and prokinetic agents are all part of gastroparesis management. In this manuscript, we detail treatments evolving for gastroparesis, including nutritional, pharmaceutical, device, and recent advanced endoscopic and surgical therapies. This manuscript concludes with a speculative viewpoint on how the field will evolve in 5 years' time.

EXPERT OPINION

Identification of the dominant symptoms (fullness, nausea, abdominal pain, and heartburn) helps to direct management efforts of the patients. Treatments for refractory (treatment resistant) symptoms may include gastric electric stimulation and intra-pyloric interventions like botulinum toxin and endoscopic pyloromyotomy. Understanding the pathophysiology of gastroparesis, relating pathophysiologic abnormalities to specific symptoms, new efficacious pharmacotherapies, and better understanding of the clinical predictors of response of therapies, are priorities for future research in the field of gastroparesis.

Review article: An analysis of the pharmacological rationale for selecting drugs to inhibit vomiting or increase gastric emptying during treatment of gastroparesis

BACKGROUND

Drugs which can inhibit nausea/vomiting and/or increase gastric emptying are used to treat gastroparesis, mostly 'off-label'. Within each category, they act at different targets and modulate different physiological mechanisms.

AIMS

Address the questions: In gastroparesis, why should blocking one pathway causing vomiting, be more appropriate than another? Why might increasing gastric emptying via one mechanism be more appropriate than another?

METHODS

Drugs used clinically were identified via consensus opinions and reviews, excluding the poorly characterised. Their pharmacology was defined, mapped to mechanisms influencing vomiting and gastric emptying, and rationale developed for therapeutic use.

RESULTS

Vomiting: Rationale for 5-HT₃ , D₂ , H₁ or muscarinic antagonists, and mirtazapine, amitriptyline, nortriptyline, are poor. Arguments for inhibiting central consequences of vagal afferent transmission by NK₁ antagonism are complicated by doubts over effects on nausea. Gastric emptying: Confusion emerges because of side-effects of drugs increasing gastric emptying: Metoclopramide (5-HT₄ agonist, D₂ and 5-HT₃ antagonist; also blocks some emetic stimuli and causes tardive dyskinesia) and Erythromycin (high-efficacy motilin agonist, requiring low doses to minimise side-effects). Limited trials with selective 5-HT₄ agonists indicate variable efficacy.

CONCLUSIONS

Several drug classes inhibiting vomiting have no scientific rationale. NK₁ antagonism has rationale but complicated by limited efficacy against nausea. Studies must resolve variable efficacy of selective 5-HT₄ agonists and apparent superiority over motilin agonists. Overall, lack of robust activity indicates a need for novel approaches targeting nausea (e.g., modulating gastric pacemaker or vagal activity, use of receptor agonists or new targets such as GDF15) and objective assessments of nausea.

Gastroparesis syndromes: emerging drug targets and potential therapeutic opportunities

INTRODUCTION

Gastroparesis (Gp) and related disorders such as chronic unexplained nausea and vomiting and functional dyspepsia, known as gastropareis syndromes (GpS), have large unmet needs. Mainstays of GpS treatments are diet and drugs.

AREAS COVERED

The purpose of this review is to explore potential new medications and other therapies for gastroparesis. Before discussing possible new drugs, the currently used drugs are discussed. These include dopamine receptor antagonists, 5-hydroxytryptamine receptor agonists and antagonists, neurokinin-1 receptor antagonists and other anti-emetics. The article also considers future drugs that may be used for Gp, based on currently known pathophysiology.

EXPERT OPINION

Gaps in knowledge about the pathophysiology of gastroparesis and related syndromes are critical to developing therapeutic agents that will be successful. Recent major developments in the gastroparesis arena are related to microscopic anatomy, cellular function, and pathophysiology. The major challenges moving forward will be to develop the genetic and biochemical correlates of these major developments in gastroparesis research.

Gastroparesis: An Evidence-Based Review for the Bariatric and Foregut Surgeon

Gastroparesis is a gastric motility disorder characterized by delayed gastric emptying. It is a rare disease and difficult to treat effectively; management is a dilemma for gastroenterologists and surgeons alike. We conducted a systematic review of the literature to evaluate current diagnostic tools as well as treatment options. We describe key elements in the pathophysiology of the disease, in addition to current evidence on treatment alternatives, including nutritional considerations, medical and surgical options, and related outcomes.

Neural networks involved in nausea in adult humans: A systematic review

Nausea is a common clinical symptom, poorly managed with anti-emetic drugs. To identify potential brain regions which may be therapeutic targets we systematically reviewed brain imaging in subjects reporting nausea. The systematic review followed PRISMA statements with methodological quality (MINORS) and risk of bias (ROBINS-I) assessed. Irrespective of the nauseagenic stimulus the common (but not only) cortical structures activated were the inferior frontal gyrus (IFG), the anterior cingulate cortex (ACC) and the anterior insula (AIns) with some evidence for lateralization (Left-IFG, Right-AIns, Right-ACC). Basal ganglia structures (e.g., putamen) were also consistently activated. Inactivation was rarely reported but occurred mainly in the cerebellum and occipital lobe. During nausea, functional connectivity increased, mainly between the posterior and mid- cingulate cortex. Limitations include, a paucity of studies and stimuli, subject demographics, inconsistent definition and measurement of nausea. Structures implicated in nausea are discussed in the context of knowledge of central pathways for interoception, emotion and autonomic control. Comparisons are made between nausea and other aversive sensations as multimodal aversive conscious experiences.

Gastroparesis and Functional Dyspepsia: Spectrum of Gastroduodenal Neuromuscular Disorders or Unique Entities?

Gastroparesis is defined by delayed gastric emptying in the absence of mechanical obstruction of the stomach. Patients experience symptoms of nausea, vomiting, abdominal pain, fullness, and early satiety. The recognition of the disorder has progressed due to availability of gastric emptying scintigraphy and advancements made in understanding its pathophysiology and treatment options. The clinical presentation and treatment of gastroparesis overlap with a more commonly recognized disorder of gut-brain interaction, functional dyspepsia. Recent studies have reenergized the discussion whether these two are separate entities or perhaps reflect a spectrum of gastroduodenal neuromuscular disorders. The societal guidelines conflict on the utility of gastric emptying scintigraphy in assessment of patients with upper gastrointestinal symptoms. A better appraisal of similarities and differences between gastroparesis and functional dyspepsia will allow targeted treatment for these disorders. This is particularly important as specific pharmacological and endoscopic treatment options are being developed for gastroparesis which are unlikely to be helpful for functional dyspepsia. This review makes the case for considering these disorders in a spectrum where identification of both would most ideally position us toward providing the optimal clinical care.

Progress in Gastroparesis - A Narrative Review of the Work of the Gastroparesis Clinical Research Consortium

The Gastroparesis Clinical Research Consortium is a multicenter coalition created and funded by the National Institutes of Diabetes and Digestive and Kidney Disorders, with a mission to advance understanding of the pathophysiology of gastroparesis and develop an effective treatment for patients with symptomatic gastroparesis. In this review, we summarize the results of the published Gastroparesis Clinical Research Consortium studies as a ready and convenient resource for gastroenterologists and others to provide a clear understanding of the consortium's experience and perspective on gastroparesis and related disorders.

Normal and disordered gastric emptying in diabetes: recent insights into (patho)physiology, management and impact on glycaemic control

Gastric emptying is a major determinant of postprandial blood glucose, accounting for ~35% of variance in peak glucose in both healthy individuals and those with type 2 diabetes. Gastric emptying is frequently disordered in individuals with diabetes (both abnormally delayed and accelerated). Delayed gastric emptying, i.e. diabetic gastroparesis, may be linked to upper gastrointestinal symptoms for which current treatment remains suboptimal; pharmacological acceleration of delayed emptying is only weakly associated with symptom improvement. Accordingly, the relationship between symptoms and delayed gastric emptying is not simply 'cause and effect'. In insulin-treated patients, disordered gastric emptying, even when not associated with gastrointestinal symptoms, can cause a mismatch between the onset of insulin action and the availability of absorbed carbohydrate, leading to suboptimal glycaemic control. In patients with type 2 diabetes, interventions that slow gastric emptying, e.g. glucagon-like peptide-1 receptor agonists, reduce postprandial blood glucose. This review focuses on recent insights into the impact of gastric emptying on postprandial blood glucose, effects of diabetes therapy on gastric emptying and the management of disordered gastric emptying in diabetes. In view of the broad relevance of gastric emptying to diabetes management, it is important that future clinical trials evaluating novel therapies that may affect gastric emptying should quantify the latter with an appropriate technique, such as scintigraphy or a stable isotope breath test.

A New Paradigm Shift in Gastroparesis Management

Gastroparesis, once regarded as a rare disease, is difficult to diagnose and challenging to treat; there were many breakthrough advances in the 2010s, shifting the paradigm of the understanding of this complex entity and its management. Similar to diabetes, its increasing prevalence reflects increased accessibility to diagnostic modalities and suggests that gastroparesis was underacknowledged in the past. Major developments in the three main aspects of the disease include the discovery of smooth muscle cells, interstitial cells of Cajal, PDGFRα+ cells syncytium, rather than interstitial cells of Cajal alone, as the main gastric pacemaker unit; the development of validated point-of-care diagnostic modalities such as a wireless motility capsule, the carbon 13-labeled breath test, and impedance planimetry; and the introduction of novel minimally invasive therapeutic options such as newer pharmacologic agents and gastric peroral endoscopic pyloromyotomy. All aspects of these advances will be discussed further in this review.

Response and Adverse Event Rates With Placebo in Gastroparesis: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Multiple drugs have been used to treat gastroparesis symptoms, yet their therapeutic benefits are poorly understood partly due to lack of insight into response and adverse event rates with placebo in randomized controlled trials (RCTs). We evaluated these issues systematically in drug trials for gastroparesis.

METHODS

We searched the medical literature through August 2, 2022 to identify RCTs comparing active drug with placebo in patients with gastroparesis. We assessed placebo response rates according to at least one of the following endpoints: improvement according to a composite outcome, nausea, vomiting, abdominal pain, bloating, or fullness, as well as total adverse events, and adverse events leading to withdrawal. We extracted data as intention-to-treat analyses with dropouts assumed to be treatment failures. We pooled placebo response and adverse event rates using a random effects model and expressed as proportions with 95% confidence intervals (CIs).

RESULTS

Thirty-five studies were eligible. Among 23 trials reporting a composite endpoint of improvement, the pooled placebo response rate was 29.3% (95% CI, 23.7%-35.2%). Pooled placebo response rates were higher in idiopathic compared with diabetic gastroparesis (34.2% vs 28.1%), among trials that did not use validated symptom questionnaires (31.2% vs 27.4%), and in RCTs of shorter duration (<4 weeks, 32.6% vs ≥9 weeks, 23.2%). Adverse events occurred in 33.8% (95% CI, 26.4%-41.8%) of patients with placebo, in 27 trials, and were less common in idiopathic compared with diabetic gastroparesis (17.9% vs 43.4%), trials of shorter duration (<4 weeks, 33.7% vs ≥9 weeks, 40.7%), and trials with lower randomization ratios of active drug to placebo (1:1, 26.7% vs 3:1, 50.5%).

CONCLUSIONS

This meta-analysis assessed placebo response and adverse event rates in gastroparesis. To accurately assess therapeutic gain, future trials should be a minimum of 8 weeks duration, use validated questionnaires, and distinguish gastroparesis subtypes.

ACG Clinical Guideline: Gastroparesis

Gastroparesis is characterized by symptoms suggesting retention of food in the stomach with objective evidence of delayed gastric emptying in the absence of mechanical obstruction in the gastric outflow. This condition is increasingly encountered in clinical practice. These guidelines summarize perspectives on the risk factors, diagnosis, and management of gastroparesis in adults (including dietary, pharmacological, device, and interventions directed at the pylorus), and they represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation process. When the evidence was not appropriate for Grading of Recommendations, Assessment, Development, and Evaluation, we used expert consensus to develop key concept statements. These guidelines should be considered as preferred but are not the only approaches to these conditions.

A cross-sectional study describing peripheral neuropathy in patients with symptoms of gastroparesis: associations with etiology, gastrointestinal symptoms, and gastric emptying

Background

Peripheral neuropathy (PN) is present in diabetic gastroparesis but is not described in idiopathic gastroparesis.

Aims

(1) Determine prevalence of PN in idiopathic gastroparesis; (2) assess if patients with symptoms of gastroparesis and PN differ in gastric emptying and symptoms, both gastrointestinal and psychosocial, from patients without PN (nPN); (3) compare this relationship to that in other etiological groups.

Methods

250 patients with symptoms of gastroparesis underwent gastric emptying scintigraphy and answered questionnaires including severity of gastroparesis symptoms using the Gastroparesis Cardinal Symptom Index (GCSI) and presence of peripheral neuropathy using the Neuropathy Total Symptom Score-6 (NTSS-6).

Results

PN, defined by NTSS-6 > 6, was present in 70/250 (28%) patients: 22/148 (15%) idiopathic, 33/61 (54%) diabetic, and 11/32 (34%) postsurgical (p < 0.01). Among 148 patients with symptoms of idiopathic gastroparesis, defined as non-diabetic, non-postsurgical, and not caused by a known disorder such as Parkinson’s or connective tissue disease, symptoms of gastroparesis were more severe in PN than nPN: bloating (4.05 ± 1.17 vs. 2.99 ± 1.61, p < 0.01), abdominal distension (3.86 ± 1.49 vs. 2.45 ± 1.68, p < 0.01), and upper abdominal pain (3.64 ± 1.22 vs. 2.71 ± 1.78, p = 0.03). Ninety-nine idiopathic patients underwent gastric emptying scintigraphy: 7/43 (16%) patients with delayed gastric emptying and 9/56 (16%) patients with normal gastric emptying had PN. Among patients with idiopathic gastroparesis, abdominal distension (4.43 ± 0.53 vs. 2.89 ± 1.68, p = 0.01) was more severe in PN than nPN. The association of PN and worse gastrointestinal symptoms was not as apparent in patients with symptoms of diabetic or postsurgical gastroparesis.

Conclusions

PN was present in 70/250 (28%) of patients with symptoms of gastroparesis and was present to a lesser extent in idiopathic than diabetic gastroparesis. The presence of PN in IG was associated with more severe gastroparetic symptoms than in nPN. Screening for PN may help identify a gastroparesis cohort with peripheral neuropathy who are more symptomatic.

AGA Clinical Practice Update on Management of Medically Refractory Gastroparesis: Expert Review

DESCRIPTION

Delayed gastric emptying on objective testing defines gastroparesis, but symptoms overlap with functional dyspepsia and do not correlate well with gastric emptying delay. This review outlines a strategy for defining, diagnosing, and managing refractory gastroparesis.

METHODS

The Best Practice Advice statements presented here were developed from review of existing literature combined with expert opinion to provide practical advice. Because this was not a systematic review, formal rating of the quality of evidence or strength of recommendations was not performed. BEST PRACTICE ADVICE.

Diabetic Gastroenteropathy: Soothe the Symptoms or Unravel a Cure?

Autonomic neuropathy in patients with diabetes mellitus, and especially complications related to gastrointestinal neuropathy, are often overlooked in the clinic. Diabetic gastroenteropathy affects every segment of the gastrointestinal tract and generates symptoms that may include nausea, early satiety, vomiting, abdominal pain, constipation, and diarrhea. Severe cases can be complicated by weight loss, dehydration, and electrolyte disturbances. The pathophysiology is complex, the diagnostics and treatment options are multidisciplinary, and there is generally a lack of evidence for the treatment options. The aims for this review are first to summarize the pathophysiology and describe possible and expected symptoms and complications.Further, we will try to supply the clinician with a straightforward tool for diagnostics, and then, we shall summarize established treatment options, including diet recommendations, pharmacological and non-pharmacological options. Finally, we will explore the multiple possibilities of novel treatment, looking at medications related to the pathophysiology of neuropathy, other manifestations of autonomic neuropathies, and symptomatic treatment for other gastrointestinal disorders, also including new knowledge of endosurgical and neuromodulatory treatment. The overall goal is to increase awareness and knowledge on this frequent diabetic complication and to provide better tools for diagnosis and treatment. Ultimately, we hope to encourage further research in this field, as there are clear shortcomings in terms of biomarkers, pathophysiology, as well as treatment possibilities. In conclusion, diagnosis and management of diabetic gastroenteropathy are challenging and often require multidisciplinary teams and multimodal therapies. Treatment options are sparse, but new pharmacological, endoscopic, and neuromodulatory techniques have shown promising results in initial studies.

Management of Gastroparesis

Gastroparesis is a gastrointestinal motility disorder characterized by nausea, vomiting, early satiation, postprandial fullness, bloating, and upper abdominal pain. The diagnosis requires documented delay in gastric emptying with an optimal test such as scintigraphy or stable isotope gastric emptying breath test in the absence of mechanical obstruction. The pathophysiologic mechanisms of gastroparesis are multifactorial, including antroduodenal hypomotility, pylorospasm, impaired gastric accommodation, and visceral hypersensitivity. The etiologies of gastroparesis are broad, but the most common subtypes are idiopathic, diabetic, and postsurgical. Less frequent etiologies are neurodegenerative disorder (Parkinson disease), myopathies (scleroderma, amyloidosis), and neoplastic syndrome. Symptoms of gastroparesis can be refractory and challenging to manage, leading to reduced quality of life and significant health care expenditure. This article introduces the epidemiology, clinical presentation, diagnosis, and differential diagnoses of gastroparesis, followed by a focused discussion on its management, including nutritional support, prokinetic and antiemetic agents, and emerging interventions directed at the pylorus. Robust sham-controlled trials are needed to evaluate the long-term efficacy of gastric peroral endoscopic myotomy. A multidisciplinary approach with individualized strategies based on characterization of the patho-physiology is deemed necessary to enhance clinical outcomes.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on gastroparesis

BACKGROUND

Gastroparesis is a condition characterized by epigastric symptoms and delayed gastric emptying (GE) rate in the absence of any mechanical obstruction. The condition is challenging in clinical practice by the lack of guidance concerning diagnosis and management of gastroparesis.

METHODS

A Delphi consensus was undertaken by 40 experts from 19 European countries who conducted a literature summary and voting process on 89 statements. Quality of evidence was evaluated using grading of recommendations assessment, development, and evaluation criteria. Consensus (defined as ≥80% agreement) was reached for 25 statements.

RESULTS

The European consensus defined gastroparesis as the presence of symptoms associated with delayed GE in the absence of mechanical obstruction. Nausea and vomiting were identified as cardinal symptoms, with often coexisting postprandial distress syndrome symptoms of dyspepsia. The true epidemiology of gastroparesis is not known in detail, but diabetes, gastric surgery, certain neurological and connective tissue diseases, and the use of certain drugs recognized as risk factors. While the panel agreed that severely impaired gastric motor function is present in these patients, there was no consensus on underlying pathophysiology. The panel agreed that an upper endoscopy and a GE test are required for diagnosis. Only dietary therapy, dopamine-2 antagonists and 5-HT₄ receptor agonists were considered appropriate therapies, in addition to nutritional support in case of severe weight loss. No consensus was reached on the use of proton pump inhibitors, other classes of antiemetics or prokinetics, neuromodulators, complimentary, psychological, or more invasive therapies. Finally, there was consensus that gastroparesis adversely impacts on quality of life and healthcare costs and that the long-term prognosis of gastroparesis depends on the cause.

CONCLUSIONS AND INFERENCES

A multinational group of European experts summarized the current state of consensus on definition, symptom characteristics, pathophysiology, diagnosis, and management of gastroparesis.

Predictors of Early Readmissions in Hospitalized Patients With Gastroparesis: A Nationwide Analysis

Background/Aims

Gastroparesis is a chronic gastrointestinal disorder that frequently presents with symptoms that are difficult to manage, necessitating frequent hospitalizations. We sought to determine the predictors of early readmission due to gastroparesis based on etiology.

Methods

We identified all adults discharged with a principal diagnosis of gastroparesis after hospitalization from the 2014 Nationwide Readmission Database. We compared etiology wise (diabetes, post-surgical, and idiopathic) early readmission. Multivariate regression analyses were performed to identify significant predictors of 30-day readmission.

Results

A total of 12 689 patients were identified, 30.7% diabetic, 2.6% post-surgical, and 66.7% were idiopathic. Patients with diabetic gastroparesis were more likely to be readmitted within 30 days than idiopathic (adjusted odds ratio [aOR], 0.81; 95% confidence interval [CI], 0.69-0.94) and post-surgical gastroparesis (aOR, 0.58; 95% CI, 0.34-0.98). Pyloroplasty was associated with less likelihood of 30-day readmission (aOR, 0.45; 95% CI, 0.20-0.97). In addition, male gender (aOR, 1.18; 95% CI, 1.02-1.37), modified Elixhauser comorbidity score ≥ 3 (aOR, 1.38; 95% CI, 1.18-1.61), chronic pain syndrome (aOR, 1.41; 95% CI, 1.11-1.78), younger (18-64 years) age (aOR, 1.64; 95% CI, 1.34-2.00), need for percutaneous endoscopic gastrostomy/jejunostomy tube (aOR, 2.06; 95% CI, 1.21-3.52), and need for total parenteral nutrition (aOR, 1.70; 95% CI, 1.24-2.35) were associated with increased risk of 30-day readmission.

Conclusions

One in 5 patients was readmitted with gastroparesis within 30 days. In the diabetic group, diabetes-related complications contributed to readmissions than gastroparesis. Pyloroplasty is associated with reduced early hospital readmission. Prospective studies are needed for validation of these results.

Nutrient Drinking Test as Biomarker in Functional Dyspepsia

INTRODUCTION

Functional dyspepsia (FD) is a prevalent condition with multifactorial pathophysiology, including impaired gastric accommodation (GA), hypersensitivity to gastric distention, and delayed gastric emptying. Drink tests (DT) have been proposed as a potential biomarker for the presence and severity of gastric sensorimotor dysfunction. Thus, we aimed to summarize the state of knowledge on different DT and their potential as a biomarker for FD.

METHODS

A PubMed and MEDLINE search was conducted for English language articles, reviews, meta-analyses, case series, and randomized controlled trials, including also published meeting abstracts.

RESULTS

Several DT have been described in literature (e.g., different type of liquid, number of calories used, pace of drinking, and subject's awareness of the amount of liquid drunk). FD patients ingest significantly less volume in the different variants of the tests. The slow nutrient ("satiety drinking") test (SDT) studies show the most consistent separation between health and FD and correlation with GA. However, sensitivity to distention may be correlated with rapid DT. SDTs were used to evaluate the effect of several pharmacological agents, often showing concordance between their effects on GA and tolerated nutrient volume. This correlation was not found mainly for agents with central actions.

DISCUSSION

An SDT is a potential diagnostic biomarker in FD, reflecting GA. Additional studies are required to confirm its role as a predictive biomarker for treatment outcome in FD.

United European Gastroenterology (UEG) and European Society for Neurogastroenterology and Motility (ESNM) consensus on gastroparesis

Background

Gastroparesis is a condition characterized by epigastric symptoms and delayed gastric emptying (GE) rate in the absence of any mechanical obstruction. The condition is challenging in clinical practice by the lack of guidance concerning diagnosis and management of gastroparesis.

Methods

A Delphi consensus was undertaken by 40 experts from 19 European countries who conducted a literature summary and voting process on 89 statements. Quality of evidence was evaluated using grading of recommendations assessment, development, and evaluation criteria. Consensus (defined as ≥80% agreement) was reached for 25 statements.

Results

The European consensus defined gastroparesis as the presence of symptoms associated with delayed GE in the absence of mechanical obstruction. Nausea and vomiting were identified as cardinal symptoms, with often coexisting postprandial distress syndrome symptoms of dyspepsia. The true epidemiology of gastroparesis is not known in detail, but diabetes, gastric surgery, certain neurological and connective tissue diseases, and the use of certain drugs recognized as risk factors. While the panel agreed that severely impaired gastric motor function is present in these patients, there was no consensus on underlying pathophysiology. The panel agreed that an upper endoscopy and a GE test are required for diagnosis. Only dietary therapy, dopamine‐2 antagonists and 5‐HT₄ receptor agonists were considered appropriate therapies, in addition to nutritional support in case of severe weight loss. No consensus was reached on the use of proton pump inhibitors, other classes of antiemetics or prokinetics, neuromodulators, complimentary, psychological, or more invasive therapies. Finally, there was consensus that gastroparesis adversely impacts on quality of life and healthcare costs and that the long‐term prognosis of gastroparesis depends on the cause.

Conclusions and Inferences

A multinational group of European experts summarized the current state of consensus on definition, symptom characteristics, pathophysiology, diagnosis, and management of gastroparesis.

Current knowledge

The epidemiology of gastroparesis is not well known.

Diagnosis and treatment of gastroparesis is challenging due to uncertainties in definition and optimal therapeutic approach.

What is new here

A Delphi panel consisting of 40 experts from 19 European countries established the level of consensus on 89 statements regarding gastroparesis.

The statements reaching consensus serve to guide clinicians in recognizing, diagnosing and treating gastroparesis in clinical practice.

The statements without consensus identify areas in need of future research.

Practical management approach to gastroparesis

Gastroparesis is a syndrome characterised by delayed gastric emptying in the absence of mechanical obstruction. Symptoms can include early satiety, abdominal pain, bloating, vomiting and regurgitation which cause significant morbidity in addition to nutritional deficits. There is a higher prevalence in diabetics and females, but the incidence in the Australian population has not been well studied. Management of gastroparesis involves investigating and correcting nutritional deficits, optimising glycaemic control and improving gastrointestinal motility. Symptom control in gastroparesis can be challenging. Nutritional deficits should be addressed initially through dietary modification. Enteral feeding is a second-line option when oral intake is insufficient. Home parenteral nutrition is rarely used, and only accessible through specialised clinics in the outpatient setting. Prokinetic medication classes that have been used include dopamine receptor antagonists, motilin receptor agonists, 5-HT₄ receptor agonists and ghrelin receptor agonists. Anti-emetic agents are often used for symptom control. Interventional treatments include gastric electrical stimulation, gastric per-oral endoscopic myotomy, feeding jejunostomy and gastrostomy/jejunstomy for gastric venting and enteral feeding. In this article we propose a framework to manage gastroparesis in Australia based on current evidence and available therapies.

Nausea and Vomiting in 2021: A Comprehensive Update

GOAL

A comprehensive review of treatments for nausea and vomiting (N/V).

BACKGROUND

N/V are common symptoms encountered in medicine. While most cases of acute N/V related to a specific cause can be straightforward to manage, other cases of acute N/V such as chemotherapy-induced N/V and especially chronic unexplained N/V can be difficult to control, leading to a significant decline in the patient's quality of life and increased cost of medical care from repeated hospitalizations.

STUDY

Traditional management has relied on pharmacotherapy which may be inadequate in a certain proportion of these patients. Many of the medications used in the management of N/V have significant side effect profiles making the need for new and improved interventions of great importance.

RESULTS

This review covers a broad review of the pathophysiology of N/V, pharmacotherapy, including safety concerns and controversies with established pharmaceuticals, newer immunotherapies, bioelectrical neuromodulation (including gastric electrical stimulation), behavioral and surgical therapies, and complementary medicine.

CONCLUSION

On the basis of emerging understandings of the pathophysiology of N/V, improved therapies are becoming available.

Marijuana, Ondansetron, and Promethazine Are Perceived as Most Effective Treatments for Gastrointestinal Nausea

BACKGROUND

Many anti-nausea treatments are available for chronic gastrointestinal syndromes, but data on efficacy and comparative effectiveness are sparse.

AIMS

To conduct a sectional survey study of patients with chronic nausea to assess comparative effectiveness of commonly used anti-nausea treatments.

METHODS

Outpatients at a single center presenting for gastroenterology evaluation were asked to rate anti-nausea efficacy on a scale of 0 (no efficacy) to 5 (very effective) of 29 commonly used anti-nausea treatments and provide other information about their symptoms. Additional information was collected from the patients' chart. The primary outcome was to determine which treatments were better or worse than average using a t test. The secondary outcome was to assess differential response by individual patient characteristics using multiple linear regression.

RESULTS

One hundred and fifty-three patients completed the survey. The mean efficacy score of all anti-nausea treatments evaluated was 1.73. After adjustment, three treatments had scores statically higher than the mean, including marijuana (2.75, p < 0.0001), ondansetron (2.64, p < 0.0001), and promethazine (2.46, p < 0.0001). Several treatments, including many neuromodulators, complementary and alternative treatments, erythromycin, and diphenhydramine had scores statistically below average. Patients with more severe nausea responded better to marijuana (p = 0.036) and diphenhydramine (p < 0.001) and less so to metoclopramide (p = 0.020). There was otherwise no significant differential response by age, gender, nausea localization, underlying gastrointestinal cause of nausea, and GCSI.

CONCLUSIONS

When treating nausea in patients with chronic gastrointestinal syndromes, clinicians may consider trying higher performing treatments first, and forgoing lower performing treatments. Further prospective research is needed, particularly with respect to highly effective treatments.

Gastroparesis and functional dyspepsia: different diseases or different ends of the spectrum?

PURPOSE OF REVIEW

This review assesses the relationship between gastroparesis and functional dyspepsia, in light of recent research assessing cause, pathophysiology and treatment.

RECENT FINDINGS

The Gastroparesis Cardinal Symptom Index (GCSI) lacks the ability to readily distinguish functional dyspepsia from gastroparesis based on symptoms. Although prior studies found that the extent of delay in gastric emptying did not accurately predict severity of symptoms, when optimally measured, delayed gastric emptying may in fact correlate with gastroparesis symptoms. Enteric dysmotility may be an important risk factor for gastroparesis. Altered central processing may play a role in symptom generation for both gastroparesis and functional dyspepsia based on functional brain MRI. Treatment directed towards reducing low-grade inflammation and improving mucosal barrier function in the duodenum may represent a novel therapeutic target for functional dyspepsia, whereas gastric peroral endoscopy myotomy (G-POEM) remains a promising intervention for refractory gastroparesis.

SUMMARY

Abnormalities on functional MRI of the brain have been identified in patients with functional dyspepsia and gastroparesis. Small bowel dysmotility and duodenal barrier dysfunction have been implicated in the pathophysiology of gastroparesis and functional dyspepsia, respectively. New treatments for functional dyspepsia may target low-grade duodenal inflammation and barrier dysfunction. The pylorus remains a target in gastroparesis.

Targeting Treatment of Gastroparesis: Use of Clinical Tests to Guide Treatments

Gastroparesis presents with nausea, vomiting, and other upper gut symptoms, and is diagnosed by confirming delayed gastric emptying. A related condition, chronic unexplained nausea and vomiting, has similar symptoms but with normal emptying. Both conditions are managed using therapies with diverse mechanisms of action. Even though prokinetic treatments are proposed to improve gastroparesis by accelerating gastric emptying, there is limited evidence that they provide benefit by virtue of transit stimulating effects. Other tests can delineate alterations in other gut sensorimotor parameters in patients with suspected gastroparesis, but their relation to symptoms and their capability to guide treatment are largely unproved.

Symptoms Suggestive of Gastroparesis in a Community-Based Cohort of European Americans and African Americans with Type 2 Diabetes Mellitus

BACKGROUND

Although gastroparesis is seen in patients with type 2 diabetes mellitus (T2DM), the prevalence of symptoms suggestive of gastroparesis in patients with T2DM is unknown, particularly among African Americans.

AIMS

To determine the prevalence of symptoms associated with gastroparesis in a large community-based population of European Americans and African Americans with T2DM.

METHODS

Individuals with T2DM in the Diabetes Heart Study were asked to complete the gastroparesis cardinal symptom index (GCSI) and other GI-related questionnaires. GCSI total score ≥ 18 represented moderate or worse symptoms suggestive of gastroparesis.

RESULTS

A total of 1253 participants (700 female, 553 male) completed the GCSI: 750 were European American and 503 African American. GCSI scores ≥ 18 were recorded in 72 participants: 38 (5%) of European Americans and 34 (7%) of African Americans. The average GCSI was 24.1 in European Americans and 24.6 in African Americans, indicating moderate to severe symptoms. Compared to European Americans with GCSI scores ≥ 18, African Americans were younger (59.4 vs. 53.3 years, p = 0.004), had earlier onset of T2DM (46.3 vs. 40.1 years, p = 0.01), higher HbA1c (7.6 vs. 9.1, p = 0.0009), underwent fewer upper endoscopies (55.3% vs. 26.5%, p = 0.02), and had more anxiety and depression (p < 0.001).

CONCLUSIONS

Moderate or greater symptoms suggestive of gastroparesis are present in 5-7% of European and African American patients with T2DM in community-based populations. Symptoms suggestive of gastroparesis may be underappreciated in patients with T2DM and account for upper gastrointestinal symptoms, unexplained glycemic control issues, and decreased quality of life.

Pathophysiology, Aetiology and Treatment of Gastroparesis

Gastroparesis is characterized by delayed gastric emptying, with symptoms such as nausea, vomiting and abdominal pain, in the absence of mechanical obstruction. In most cases, it is idiopathic although diabetes mellitus is another leading cause. The physiology of gastric emptying is a complex process which is influenced by various inputs including the central nervous system, enteric nervous system and gut hormones. Developments in our understanding of gastroparesis have now demonstrated dysfunction in these systems, thus disrupting normal gastric emptying. Once mechanical obstruction is excluded, gastric scintigraphy remains the gold standard for diagnosis although wireless motility capsule and breath testing are alternative methods for diagnosis. Treatment for gastroparesis is challenging, and widely available therapies are often limited either by their poor evidence for efficacy or concerns over their long-term safety profile. Novel prokinetic agents have shown initial promise in clinical trials, and new endoscopic techniques such as gastric per-oral endoscopic myotomy are emerging. These new treatment modalities may provide an option in refractory gastroparesis with the adage of reduced morbidity compared to surgical treatments.

Overall safety of relamorelin in adults with diabetic gastroparesis: Analysis of phase 2a and 2b trial data

BACKGROUND

Relamorelin, a pentapeptide ghrelin receptor agonist, accelerated gastric emptying significantly and improved symptoms in adults with diabetic gastroparesis in phase 2 trials.

AIM

To assess the safety and tolerability of relamorelin across phase 2 trials.

METHODS

Safety assessments in patients aged 18-75 years (weight, adverse events [AEs] and laboratory tests) from two randomised, double-blind phase 2 trials (NCT01571297, NCT02357420; results published previously) were reviewed descriptively. Analysis of covariance assessed treatment effect on glycated haemoglobin (HbA1c) and blood glucose post hoc. Phase 2a and 2b trial durations were, respectively, 4 weeks (relamorelin 10 µg once or twice daily [b.d.] or placebo b.d.) and 12 weeks (relamorelin 10, 30 or 100 µg or placebo b.d.) with 1- and 2-week, single-blind placebo run-ins.

RESULTS

Among 204 phase 2a and 393 phase 2b patients, respectively, 67% and 62% were female, and 88% and 89% had type 2 diabetes. Proportions of patients reporting serious AEs were similar across treatment groups, as were those with ≥1 treatment-emergent AE (TEAE). TEAE-related discontinuations were proportionally higher in relamorelin groups than placebo. Of 12 serious TEAEs in phase 2a, none occurred in >1 patient. In phase 2b, five serious TEAEs were reported in >1 patient, and one (100 µg) died (urosepsis), all unrelated to relamorelin. In phase 2b, increased HbA1c and fasting blood glucose levels were dose-related (P < 0.0001 and P = 0.0043, respectively).

CONCLUSIONS

Relamorelin showed acceptable safety and tolerability in phase 2 trials. Relamorelin may elevate blood glucose: this should be managed proactively in relamorelin-treated patients.

The impact of risk factors on gastroparesis at an urban medical center

Background

Gastroparesis is a complex and poorly understood disease. The literature is lacking with respect to the epidemiology of patient comorbidities and their effect on gastric emptying. We aimed to describe the most common comorbid conditions among patients with gastroparesis in an urban population and quantify the effect of these comorbidities on the severity of delayed gastric emptying (DGE).

Methods

We examined the medical records of all patients diagnosed with gastroparesis at a quaternary care center between 2014 and 2015. The severity of DGE was analyzed after patients were stratified for possible causative etiologies. Likelihood ratio tests were used to assess the significance of demographic and scintigraphic variation in this population.

Results

Of the 221 patients, 56.1% were Caucasian and 31.7% were African American. Among these patients, 29.4% had evidence of medication-associated gastroparesis, 29.0% had diabetes-associated gastroparesis, and 31.7% had idiopathic disease. African American patients with gastroparesis were more likely to have diabetic gastroparesis than patients of other races (P=0.01). There was a statistically significant relationship between the number of major risk factors and the severity of a patient's DGE (P=0.004).

Conclusions

Among a diverse urban population, patients with DGE often carry multiple comorbid conditions that serve as risk factors for the development of gastroparesis, including prescriptions for narcotic medications. Greater numbers of these comorbid conditions are associated with more severe disease. Demographics are significantly associated with the etiology and severity of gastroparesis; in particular, African American patients are more likely to have diabetic gastroparesis than patients of other races.

Status of Brain Imaging in Gastroparesis

The pathophysiology of nausea and vomiting in gastroparesis is complicated and multifaceted involving the collaboration of both the peripheral and central nervous systems. Most treatment strategies and studies performed in gastroparesis have focused largely on the peripheral effects of this disease, while our understanding of the central nervous system mechanisms of nausea in this entity is still evolving. The ability to view the brain with different neuroimaging techniques has enabled significant advances in our understanding of the central emetic reflex response. However, not enough studies have been performed to further explore the brain–gut mechanisms involved in nausea and vomiting in patients with gastroparesis. The purpose of this review article is to assess the current status of brain imaging and summarize the theories about our present understanding on the central mechanisms involved in nausea and vomiting (N/V) in patients with gastroparesis. Gaining a better understanding of the complex brain circuits involved in the pathogenesis of gastroparesis will allow for the development of better antiemetic prophylactic and treatment strategies.

Gastroparesis in the 2020s: New Treatments, New Paradigms

PURPOSE OF REVIEW

This review highlights recent work that will lead to near-term advances in the understanding and treatment of gastroparesis (Gp).

RECENT FINDINGS

Major current advancements in the pathophysiology of Gp, include recognition of the SIP syncytium as the pacemaking unit rather than ICC alone and that Gp may be part of a pan-enteric autoimmune and/or autonomic disorder with macrophage imbalance. The development of newer techniques to assess gastric emptying (gastric emptying breath test and wireless motility capsule) and pyloric distensibility (EndoFLIP®) are allowing clinicians better characterization of their patients. In addition to pharmaceutical compounds in the pipeline, neuromodulation and endosurgical techniques, such as G-POEM, may help address refractory Gp. We expect that the 2020 decade will witness exciting developments. Treatments targeting gastrointestinal motility, immunological dysfunction, and inflammatory mediators will be evaluated. We anticipate future studies will be guided by biomarkers correlated with patient outcomes and therapeutic efficacy to establish new paradigms in the management of Gp.

Impact of Cannabinoids on Symptoms of Refractory Gastroparesis: A Single-center Experience

Background and aims

Cannabinoids are increasingly used for medicinal purposes, including neuropathy. Gastroparesis is a neuromuscular disorder and neuropathy plays a large role in its pathogenesis. It is thus reasonable that cannabinoids can serve a beneficial role in the management of gastroparesis. Our study evaluates the effect of cannabinoids on gastroparesis symptoms.

Methods

Twenty-four (n=24) patients with gastroparesis and refractory symptoms were selected from a single gastroenterology practice associated with a tertiary care medical center. The ‘Gastroparesis Cardinal Symptom Index' (GCSI) and an analog scale rating abdominal pain were applied to prospectively assess the effect of cannabinoids, in the form of dronabinol and medical cannabis, on refractory gastroparesis symptoms. Patients completed a GCSI form and rated their abdominal pain, before and after treatment. There was a minimum of 60 days of cannabinoid use between reporting intervals. Total composite GCSI symptom scores, GCSI symptom subset scores, and abdominal pain scores were calculated before and after treatment.

Results

A significant improvement in the GCSI total symptom composite score was seen with either cannabinoid treatment (mean score difference of 12.8, 95% confidence interval 10.4-15.2; p-value < 0. 001). Patients prescribed marijuana experienced a statistically significant improvement in every GCSI symptom subgroup. Significant improvement in abdominal pain score was also seen with either cannabinoid treatment (mean score difference of 1.6; p-value <0.001).

Conclusions

Cannabinoids dramatically improve the symptoms of gastroparesis. Furthermore, an improvement in abdominal pain with cannabinoids represents a breakthrough for gastroparesis-associated abdominal pain treatment, for which there are currently no validated therapies.

Gastroparesis: a turning point in understanding and treatment

Gastroparesis is defined by delayed gastric emptying (GE) and symptoms of nausea, vomiting, bloating, postprandial fullness, early satiety and abdominal pain. Most common aetiologies include diabetes, postsurgical and postinfectious, but in many cases it is idiopathic. Clinical presentation and natural history vary by the aetiology. There is significant morbidity and healthcare utilisation associated with gastroparesis. Mechanistic studies from diabetic animal models of delayed GE as well as human full-thickness biopsies have significantly advanced our understanding of this disorder. An innate immune dysregulation and injury to the interstitial cells of Cajal and other components of the enteric nervous system through paracrine and oxidative stress mediators is likely central to the pathogenesis of gastroparesis. Scintigraphy and ¹³C breath testing provide the most validated assessment of GE. The stagnant gastroparesis therapeutic landscape is likely to soon see significant changes. Relatively newer treatment strategies include antiemetics (aprepitant), prokinetics (prucalopride, relamorelin) and fundic relaxants (acotiamide, buspirone). Endoscopic pyloromyotomy appears promising over the short term, especially for symptoms of nausea and vomiting. Further controlled trials and identification of the appropriate subgroup with pyloric dysfunction and assessment of long-term outcomes are essential. This review highlights the clinical presentation, diagnosis, mechanisms and treatment advancements for gastroparesis.

Role of Gastric Emptying in Symptoms of Gastroparesis

The symptoms of gastroparesis, such as nausea, vomiting, postprandial fullness, early satiety and abdominal pain, frequently impair the quality of life of the affected individuals. The diagnosis of gastroparesis is made after structural etiologies are ruled out and an assessment of gastric function shows delayed gastric emptying. The role of the delay in gastric emptying in the pathogenesis of symptoms of gastroparesis has been debated, with some studies suggesting an association between delayed gastric emptying and the upper gastrointestinal symptoms, while others do not. The recent literature supports the importance of using reliable methods to assess gastric emptying, as delay in gastric emptying measured on a reliable test (4-h scintigraphy or breath test) is associated with the severity of upper gastrointestinal symptoms. In addition to measuring total gastric emptying, evaluation of regional gastric retention in the proximal and distal stomach and whole gut transit to assess small intestinal and colonic transit may provide additional useful information in patients with more generalized symptoms of gastrointestinal dysmotility.

Influence of Gastric Emptying and Gut Transit Testing on Clinical Management Decisions in Suspected Gastroparesis

INTRODUCTION

Gastric emptying scintigraphy (GES) or wireless motility capsules (WMCs) can evaluate upper gastrointestinal symptoms in suspected gastroparesis; WMC tests can also investigate lower gut symptoms. We aimed to determine whether these tests impact treatment plans and needs for additional diagnostic evaluation.

METHODS

In a prospective, multicenter study, 150 patients with gastroparesis symptoms simultaneously underwent GES and WMC testing. Based on these results, investigators devised management plans to recommend changes in medications, diet, and surgical therapies and order additional diagnostic tests.

RESULTS

Treatment changes were recommended more often based on the WMC vs GES results (68% vs 48%) (P < 0.0001). Ordering of additional test(s) was eliminated more often with WMC vs GES (71% vs 31%) (P < 0.0001). Prokinetics (P = 0.0007) and laxatives (P < 0.0001) were recommended more often based on the WMC vs GES results. Recommendations for prokinetics and gastroparesis diets were higher and neuromodulators lower in subjects with delayed emptying on both tests (all P ≤ 0.0006). Laxatives and additional motility tests were ordered more frequently for delayed compared with normal WMC colonic transit (P ≤ 0.02). Multiple motility tests were ordered more often on the basis of GES vs WMC findings (P ≤ 0.004). Antidumping diets and transit slowing medications were more commonly recommended for rapid WMC gastric emptying (P ≤ 0.03).

DISCUSSION

WMC transit results promote medication changes and eliminate additional diagnostic testing more often than GES because of greater detection of delayed gastric emptying and profiling the entire gastrointestinal tract in patients with gastroparesis symptoms.

TRANSLATIONAL IMPACT

Gastric scintigraphy and WMCs have differential impact on management decisions in suspected gastroparesis.

Diabetic Gastroparesis

This review covers the epidemiology, pathophysiology, clinical features, diagnosis, and management of diabetic gastroparesis, and more broadly diabetic gastroenteropathy, which encompasses all the gastrointestinal manifestations of diabetes mellitus. Up to 50% of patients with type 1 and type 2 DM and suboptimal glycemic control have delayed gastric emptying (GE), which can be documented with scintigraphy, 13C breath tests, or a wireless motility capsule; the remainder have normal or rapid GE. Many patients with delayed GE are asymptomatic; others have dyspepsia (i.e., mild to moderate indigestion, with or without a mild delay in GE) or gastroparesis, which is a syndrome characterized by moderate to severe upper gastrointestinal symptoms and delayed GE that suggest, but are not accompanied by, gastric outlet obstruction. Gastroparesis can markedly impair quality of life, and up to 50% of patients have significant anxiety and/or depression. Often the distinction between dyspepsia and gastroparesis is based on clinical judgement rather than established criteria. Hyperglycemia, autonomic neuropathy, and enteric neuromuscular inflammation and injury are implicated in the pathogenesis of delayed GE. Alternatively, there are limited data to suggest that delayed GE may affect glycemic control. The management of diabetic gastroparesis is guided by the severity of symptoms, the magnitude of delayed GE, and the nutritional status. Initial options include dietary modifications, supplemental oral nutrition, and antiemetic and prokinetic medications. Patients with more severe symptoms may require a venting gastrostomy or jejunostomy and/or gastric electrical stimulation. Promising newer therapeutic approaches include ghrelin receptor agonists and selective 5-hydroxytryptamine receptor agonists.

Pathophysiology and management of diabetic gastroenteropathy

Polyneuropathy is a common complication to diabetes. Neuropathies within the enteric nervous system are associated with gastroenteropathy and marked symptoms that severely reduce quality of life. Symptoms are pleomorphic but include nausea, vomiting, dysphagia, dyspepsia, pain, bloating, diarrhoea, constipation and faecal incontinence. The aims of this review are fourfold. First, to provide a summary of the pathophysiology underlying diabetic gastroenteropathy. Secondly to give an overview of the diagnostic methods. Thirdly, to provide clinicians with a focussed overview of current and future methods for pharmacological and nonpharmacological treatment modalities. Pharmacological management is categorised according to symptoms arising from the upper or lower gut as well as sensory dysfunctions. Dietary management is central to improvement of symptoms and is discussed in detail, and neuromodulatory treatment modalities and other emerging management strategies for diabetic gastroenteropathy are discussed. Finally, we propose a diagnostic/investigation algorithm that can be used to support multidisciplinary management.

Cyclic vomiting syndrome: Pathophysiology, comorbidities, and future research directions

Cyclic vomiting syndrome (CVS) is characterized by severe episodic emesis in adults and children. Cannabinoid hyperemesis syndrome is an increasingly recognized CVS-like illness that has been associated with chronic cannabis use. There are significant gaps in our understanding of the pathophysiology, clinical features, comorbidities, and effective management options of CVS. Recommendations for treating CVS are based on limited clinical data, as no placebo-controlled, randomized trials have yet been conducted. Diseases associated with CVS, including migraine, mitochondrial disorders, autonomic dysfunction, and psychiatric comorbidities, provide clues about pathophysiologic mechanisms and suggest potential therapies. We review our current understanding of CVS and propose future research directions with the aim of developing effective therapy. Establishing a multicenter, standardized registry of CVS patients could drive research on multiple fronts including developing CVS-specific outcome measures to broaden our understanding of clinical profiles, to serve as treatment end points in clinical trials, and to provide a platform for patient recruitment for randomized clinical trials. Such a robust database would also facilitate conduct of research that aims to determine the underlying pathophysiological mechanisms and genetic basis for CVS, as well as identifying potential biomarkers for the disorder. Soliciting government and industry support is crucial to establishing the necessary infrastructure and achieving these goals. Patient advocacy groups such as the Cyclic Vomiting Syndrome Association (CVSA), which partner with clinicians and researchers to disseminate new information, to promote ongoing interactions between patients, their families, clinicians, investigators, to support ongoing CVS research and education, must be an integral part of this endeavor.

Therapeutic strategies in gastroparesis: Results of stepwise approach with diet and prokinetics, Gastric Rest, and PEG-J: A retrospective analysis

BACKGROUND

Gastroparesis is characterized by abnormal gastric motor function with delayed gastric emptying in the absence of mechanical obstruction. In our tertiary referral center, patients are treated with a stepwise approach, starting with dietary advice and prokinetics, followed by three months of nasoduodenal tube feeding with "gastric rest." When not successful, a percutaneous endoscopic gastrostomy with jejunal extension (PEG-J) for long-term enteral feeding is placed.

AIM

To evaluate the effect of this stepwise approach on weight and symptoms.

METHODS

Analyses of data of all referred gastroparesis patients between 2008 and 2016.

KEY RESULTS

A total of 86 patients (71% female, 20-87 years [mean 55.8 years]) were analyzed of whom 50 (58%) had adequate symptom responses to diet and prokinetics. The remaining 36 (decompensated gastroparesis) were treated with three months gastric rest. Symptom response rate was 47% (17/36). Significant weight gain was seen in all patients, independent of symptom response. In the remaining 19 symptom non-responders, the enteral feeding was continued through PEG-J. Treatment was effective (symptoms) in 37%, with significant weight gain in all. In 84% of patients, the PEG-J is still in use (mean duration 962 days).

CONCLUSIONS AND INFERENCES

Following a stepwise treatment approach in gastroparesis, adequate symptom response was reached in 86% of all patients. Weight gain was achieved in all patients, independent of symptom response. Diet and prokinetics were effective with regard to symptoms in 58%, temporary gastric rest in 47%, and PEG-J as third step in 37% of patients.