Diagnosis, characterization, and 3-month outcome after detoxification of 39 patients with narcotic bowel syndrome

Involvement of Intestinal Enteroendocrine Cells in Neurological and Psychiatric Disorders

Neurological and psychiatric patients have increased dramatically in number in the past few decades. However, effective treatments for these diseases and disorders are limited due to heterogeneous and unclear pathogenic mechanisms. Therefore, further exploration of the biological aspects of the disease, and the identification of novel targets to develop alternative treatment strategies, is urgently required. Systems-level investigations have indicated the potential involvement of the brain–gut axis and intestinal microbiota in the pathogenesis and regulation of neurological and psychiatric disorders. While intestinal microbiota is crucial for maintaining host physiology, some important sensory and regulatory cells in the host should not be overlooked. Intestinal epithelial enteroendocrine cells (EECs) residing in the epithelium throughout intestine are the key regulators orchestrating the communication along the brain-gut-microbiota axis. On one hand, EECs sense changes in luminal microorganisms via microbial metabolites; on the other hand, they communicate with host body systems via neuroendocrine molecules. Therefore, EECs are believed to play important roles in neurological and psychiatric disorders. This review highlights the involvement of EECs and subtype cells, via secretion of endocrine molecules, in the development and regulation of neurological and psychiatric disorders, including Parkinson’s disease (PD), schizophrenia, visceral pain, neuropathic pain, and depression. Moreover, the current paper summarizes the potential mechanism of EECs in contributing to disease pathogenesis. Examination of these mechanisms may inspire and lead to the development of new aspects of treatment strategies for neurological and psychiatric disorders in the future.

A review of trial and real-world data applying elements of a realist approach to identify behavioural mechanisms supporting practitioners to taper opioids

This evidence synthesis applying realist concepts and behavioural science aimed to identify behavioural mechanisms and contexts that facilitate prescribers tapering opioids. We identified relevant opioid‐tapering interventions and services from a 2018 international systematic review and a 2019 England‐wide survey, respectively. Interventions and services were eligible if they provided information about contexts and/or behavioural mechanisms influencing opioid‐tapering success. A stakeholder group (n = 23) generated draft programme theories based around the 14 domains of the Theoretical Domains Framework. We refined these using the trial and service data. From 71 articles and 21 survey responses, 56 and 16 respectively were included, representing primary care, hospital, specialist pain facilities and prison services. We identified 6 programme theories comprising 5 behavioural mechanisms: prescribers' knowledge about how to taper; build prescribers' beliefs about capabilities to initiate tapering discussions and manage psychological consequences of tapering; perceived professional role in tapering; the environmental context enabling referral to specialists; and facilitating positive social influence by aligning patient: prescriber expectations of tapering. No interventions are addressing all 6 mechanisms supportive of tapering. Work is required to operationalise programme theories according to organisational structures and resources. An example operationalisation is combining tapering guidelines with information about local excess opioid problems and endorsing these with organisational branding. Prescribers being given the skills and confidence to initiate tapering discussions by training them in cognitive‐based interventions and incorporating access to psychological and physical support in the patient pathway. Patients being provided with leaflets about the tapering process and informed about the patient pathway.

Efficacy of interventions to reduce long term opioid treatment for chronic non-cancer pain: systematic review and meta-analysis

OBJECTIVE

To review interventions to reduce long term opioid treatment in people with chronic non-cancer pain, considering efficacy on dose reduction and discontinuation, pain, function, quality of life, withdrawal symptoms, substance use, and adverse events.

DESIGN

Systematic review and meta-analysis of randomised controlled trials and non-randomised studies of interventions.

DATA SOURCES

Medline, Embase, PsycINFO, CINAHL, and the Cochrane Library searched from inception to July 2021. Reference lists and previous reviews were also searched and experts were contacted.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Original research in English. Case reports and cross sectional studies were excluded.

DATA EXTRACTION AND SYNTHESIS

Two authors independently selected studies, extracted data, and used the Cochrane risk-of-bias tools for randomised and non-randomised studies (RoB 2 and ROBINS-I). Authors grouped interventions into five categories (pain self-management, complementary and alternative medicine, pharmacological and biomedical devices and interventions, opioid replacement treatment, and deprescription methods), estimated pooled effects using random effects meta-analytical models, and appraised the certainty of evidence using GRADE (grading of recommendations, assessment, development, and evaluation).

RESULTS

Of 166 studies meeting inclusion criteria, 130 (78%) were considered at critical risk of bias and were excluded from the evidence synthesis. Of the 36 included studies, few had comparable treatment arms and sample sizes were generally small. Consequently, the certainty of the evidence was low or very low for more than 90% (41/44) of GRADE outcomes, including for all non-opioid patient outcomes. Despite these limitations, evidence of moderate certainty indicated that interventions to support prescribers' adherence to guidelines increased the likelihood of patients discontinuing opioid treatment (adjusted odds ratio 1.5, 95% confidence interval 1.0 to 2.1), and that these prescriber interventions as well as pain self-management programmes reduced opioid dose more than controls (intervention v control, mean difference -6.8 mg (standard error 1.6) daily oral morphine equivalent, P<0.001; pain programme v control, -14.31 mg daily oral morphine equivalent, 95% confidence interval -21.57 to -7.05).

CONCLUSIONS

Evidence on the reduction of long term opioid treatment for chronic pain continues to be constrained by poor study methodology. Of particular concern is the lack of evidence relating to possible harms. Agreed standards for designing and reporting studies on the reduction of opioid treatment are urgently needed.

REVIEW REGISTRATION

PROSPERO CRD42020140943.

AGA Clinical Practice Update on Management of Chronic Gastrointestinal Pain in Disorders of Gut-Brain Interaction: Expert Review

DESCRIPTION

This expert review summarizes approaches to management of pain in disorders of gut-brain interaction. This review focuses specifically on approaches to pain that persist if first-line therapies aimed at addressing visceral causes of pain are unsuccessful. The roles of a therapeutic patient-provider relationship, nonpharmacologic and pharmacologic therapies, and avoidance of opioids are discussed.

METHODS

This was not a formal systematic review but was based on a review of the literature to provide best practice advice statements. No formal rating of the quality of evidence or strength of recommendation was performed. BEST PRACTICE ADVICE 1: Effective management of persistent pain in disorders of gut-brain interaction requires a collaborative, empathic, culturally sensitive, patient-provider relationship. BEST PRACTICE ADVICE 2: Providers should master patient-friendly language about the pathogenesis of pain, leveraging advances in neuroscience and behavioral science. Providers also must understand the psychological contexts in which pain is perpetuated. BEST PRACTICE ADVICE 3: Opioids should not be prescribed for chronic gastrointestinal pain because of a disorder of gut-brain interaction. If patients are referred on opioids, these medications should be prescribed responsibly, via multidisciplinary collaboration, until they can be discontinued. BEST PRACTICE ADVICE 4: Nonpharmacologic therapies should be considered routinely as part of comprehensive pain management, and ideally brought up early on in care. BEST PRACTICE ADVICE 5: Providers should optimize medical therapies that are known to modulate pain and be able to differentiate when gastrointestinal pain is triggered by visceral factors vs centrally mediated factors. BEST PRACTICE ADVICE 6: Providers should familiarize themselves with a few effective neuromodulators, knowing the dosing, side effects, and targets of each and be able to explain to the patient why these drugs are used for the management of persistent pain.

Psychopharmacologic Therapies for Irritable Bowel Syndrome

Psychopharmacologic therapies are beneficial in reducing symptoms when treating irritable bowel syndrome (IBS) and other disorders of gut-brain interaction (DGBI). Noradrenaline, serotonin, and dopamine are neurotransmitters of key importance in psychopharmacology and pain-reduction mechanisms. The first-line (tricyclic antidepressants, serotonin noradrenaline reuptake inhibitors, selective serotonin reuptake inhibitors) and second-line (atypical antipsychotics, delta-ligand agents, low-dose naltrexone) neuromodulator treatment options are recommended when IBS-associated abdominal pain is of moderate or severe intensity and is persistent. To understand the implementation strategy, the multidimensional clinical profile as a template is used for presenting 3 case scenarios involving painful IBS and DGBI of varying complexity.

Nutritional considerations in severe primary chronic small intestinal dysmotility

PURPOSE OF REVIEW

To provide an update on the recent evidence underpinning the approach to nutritional care in patients with severe primary chronic small bowel dysmotility.

RECENT FINDINGS

Patients with severe chronic small intestinal dysmotility suffer nutritional and nonnutritional morbidity, both as a result of their underlying polysymptomatic, poorly understood condition and the interventions required. A proportion require artificial nutrition support; however, this is associated with impaired quality of life and associated complications. The approach to nutritional support must therefore engage a multidisciplinary team (MDT) to ensure that decisions to escalate beyond oral nutrition reflect individualised risk-benefit discussions while adopting a holistic approach to symptom management. Since nutritional outcomes are worse in those with the chronic intestinal pseudo-obstruction (CIPO) phenotype, differentiation into CIPO and non-CIPO subgroups, using a pragmatic diagnostic approach rather than invasive/poorly tolerated investigations, can be an important step in achieving nutritional care tailored to the individual.

SUMMARY

Malnutrition in patients with severe chronic small intestinal dysmotility is multifactorial. Early engagement of a broad team that includes dietitians, psychologists and pain management experts is crucial to achieving the most beneficial and least harmful patient-centred nutritional care outcomes.

Functional Dyspepsia: Diagnostic and Therapeutic Approaches

Functional dyspepsia is a common functional gastrointestinal (GI) disorder of gastroduodenal origin, diagnosed clinically in the presence of prototypical symptoms of epigastric pain and meal-related symptoms, and without structural explanation. The most recent diagnostic criteria provide for two functional dyspepsia subtypes, epigastric pain syndrome (EPS) and post-prandial distress syndrome (PDS) based on the predominant symptom pattern. The evaluation of dyspepsia should keep laboratory, imaging, and invasive testing to a minimum, as extensive or repetitive investigations are of rather low diagnostic yield in the absence of localizing symptoms or alarm features. Factors with etiopathologic relationships to functional dyspepsia include micro-inflammation, GI infections, abnormalities of gastroduodenal motility, visceral hypersensitivity, disturbances along the brain-gut axis, and psychological factors; all of these causative mechanisms have potential to partially explain symptoms in some functional dyspepsia patients, thus providing a rationale for the efficacy of a diversity of therapeutic approaches to functional dyspepsia. Management of dyspepsia symptoms relies upon both pharmacologic treatments and non-pharmacologic approaches, including psychological and complementary interventions. The evidence in support of established functional dyspepsia therapies is reviewed, and forms the basis for an effective functional dyspepsia treatment strategy emphasizing the patient's current symptom severity, pattern, and impact on the function and quality of life of the individual.

An opioid receptor-independent mechanism underlies motility dysfunction and visceral hyperalgesia in opioid-induced bowel dysfunction

Constipation and abdominal pain are commonly encountered in opioid-induced bowel dysfunction (OBD). The underlying mechanisms are incompletely understood, and treatments are not satisfactory. As patients with OBD often have fecal retention, we aimed to determine whether fecal retention plays a pathogenic role in the development of constipation and abdominal pain in OBD, and if so to investigate the mechanisms. A rodent model of OBD was established by daily morphine treatment at 10 mg/kg for 7 days. Bowel movements, colonic muscle contractility, visceromotor response to colorectal distention, and cell excitability of colon-projecting dorsal root ganglion neurons were determined in rats fed with normal pellet food, or with clear liquid diet. Morphine treatment (Mor) reduced fecal outputs starting on day 1, and caused fecal retention afterward. Compared with controls, Mor rats demonstrated suppressed muscle contractility, increased neuronal excitability, and visceral hypersensitivity. Expression of cyclooxygenase-2 (COX-2) and nerve growth factor (NGF) was upregulated in the smooth muscle of the distended colon in Mor rats. However, prevention of fecal retention by feeding rats with clear liquid diet blocked upregulation of COX-2 and NGF, restored muscle contractility, and attenuated visceral hypersensitivity in Mor rats. Moreover, inhibition of COX-2 improved smooth muscle function and fecal outputs, whereas anti-NGF antibody administration attenuated visceral hypersensitivity in Mor rats. Morphine-induced fecal retention is an independent pathogenic factor for motility dysfunction and visceral hypersensitivity in rats with OBD. Liquid diet may have therapeutic potential for OBD by preventing fecal retention-induced mechanotranscription of COX-2 and NGF.NEW & NOTEWORTHY Our preclinical study shows that fecal retention is a pathogenic factor in opioid-induced bowel dysfunction, as prevention of fecal retention with liquid diet improved motility and attenuated visceral hyperalgesia in morphine-treated animals by blocking expression of cyclooxygenase-2 and nerve growth factor in the colon.

The management of adult patients with severe chronic small intestinal dysmotility

Adult patients with severe chronic small intestinal dysmotility are not uncommon and can be difficult to manage. This guideline gives an outline of how to make the diagnosis. It discusses factors which contribute to or cause a picture of severe chronic intestinal dysmotility (eg, obstruction, functional gastrointestinal disorders, drugs, psychosocial issues and malnutrition). It gives management guidelines for patients with an enteric myopathy or neuropathy including the use of enteral and parenteral nutrition.

Benefits and Harms of Long-term Opioid Dose Reduction or Discontinuation in Patients with Chronic Pain: a Rapid Review

BACKGROUND

Many clinicians are reevaluating the use of long-term opioid therapy (LTOT) for chronic pain in response to the opioid crisis and calls from organizations including the Centers for Disease Control & Prevention to limit prescribing of high-dose opioids. However, this practice change is occurring largely in the absence of data regarding patient outcomes. A 2017 systematic review found inconclusive evidence on the impact of LTOT dose reduction and discontinuation on pain severity and function, quality of life, withdrawal symptoms, substance abuse, and adverse effects. This rapid systematic review provides an updated evidence synthesis of patient outcomes following LTOT dose reduction including serious harms such as overdose and suicide.

METHODS

We systematically searched numerous bibliographic databases from January 2017 (the end search date of the 2017 systematic review) through May 2020. One reviewer used prespecified criteria to assess articles for inclusion, evaluate study quality, abstract data, and grade strength of evidence, with a second reviewer checking.

RESULTS

We included 49 studies-1 systematic review, 34 studies included in that systematic review, and 14 new studies. We prioritized evidence synthesis of 19 studies with the most applicability to the Veteran population and outpatient settings. Among these studies, improvements in mean pain scores were common among patients tapering opioids while participating in intensive multimodal pain interventions and mostly unchanged with less intensive or nonspecific co-interventions. Our confidence in these findings is low due to methodological limitations of the studies. Observational data suggests that serious harms such as opioid overdose and suicidal ideation can occur following opioid dose reduction or discontinuation, but the incidence of these harms at the population level is unknown.

DISCUSSION

The net balance of benefits and harms of LTOT dose reduction for patients with chronic pain is unclear. Clinicians should closely monitor patients during the tapering process given the potential for harm.

Disorders of gut-brain interaction and the long-term risks of opioids

Prescription opioid abuse has become a public health crisis. It is often challenging to manage affected patients as their symptoms are often viewed through a prism of complex psychosocial issues. Clinicians are often unaware of the lack of evidence regarding opioid prescribing for non-cancer pain, and these trends in prescribing have been significantly escalated by pharmaceutical companies and prescribing culture in recent years. Opioid prescribing in the context of disorders of gut-brain interaction (formerly known as functional gastrointestinal disorders) can worsen conditions such as centrally-mediated abdominal pain syndrome and narcotic bowel syndrome. Opioids should not be prescribed to these patients as the harm is significantly greater than the benefit. However, in certain patients, such as those being investigated for organic abdominal pain, a trial of opioids may be indicated. In these groups, an opioid contract should be used, in addition to risk tools to identify those most vulnerable to the negative effects of these drugs. Prevention and treatment of the long-term effects of opioids requires a multidisciplinary approach and health-care professionals should all become 'opioid aware'.

Bacterial modulation of visceral sensation: mediators and mechanisms

The potential role of the intestinal microbiota in modulating visceral pain has received increasing attention during recent years. This has led to the identification of signaling pathways that have been implicated in communication between gut bacteria and peripheral pain pathways. In addition to the well-characterized impact of the microbiota on the immune system, which in turn affects nociceptor excitability, bacteria can modulate visceral afferent pathways by effects on enterocytes, enteroendocrine cells, and the neurons themselves. Proteases produced by bacteria, or by host cells in response to bacteria, can increase or decrease the excitability of nociceptive dorsal root ganglion (DRG) neurons depending on the receptor activated. Short-chain fatty acids generated by colonic bacteria are involved in gut-brain communication, and intracolonic short-chain fatty acids have pronociceptive effects in rodents but may be antinociceptive in humans. Gut bacteria modulate the synthesis and release of enteroendocrine cell mediators, including serotonin and glucagon-like peptide-1, which activate extrinsic afferent neurons. Deciphering the complex interactions between visceral afferent neurons and the gut microbiota may lead to the development of improved probiotic therapies for visceral pain.

Defining Optimal Care for Functional Gut Disorders - Multi-Disciplinary Versus Standard Care: A Randomized Controlled Trial Protocol

BACKGROUND

Functional gastrointestinal disorders (FGIDs) are the commonest reason for gastroenterological consultation, with patients usually seen by a specialist working in isolation. There is a wealth of evidence testifying to the benefit provided by dieticians, behavioral therapists, hypnotherapists and psychotherapists in treating these conditions, yet they rarely form a part of the therapeutic team, and these treatment modalities are rarely offered as part of the therapeutic management. There has been little examination of different models of care for FGIDs. We hypothesize that multi-disciplinary integrated care is superior to standard specialist-based care in the treatment of functional gut disorders.

METHODS

The "MANTRA" (Multidisciplinary Treatment for Functional Gut Disorders) study compares comprehensive multi-disciplinary outpatient care with standard hospital outpatient care. Consecutive new referrals to the gastroenterology and colorectal outpatient clinics of a single secondary and tertiary care hospital of patients with an FGID, defined by the Rome IV criteria, will be included. Patients will be prospectively randomized 2:1 to multi-disciplinary (gastroenterologist, gut-hypnotherapist, psychiatrist, behavioral therapist ('biofeedback') and dietician) or standard care (gastroenterologist or colorectal surgeon). Patients are assessed up to 12 months after completing treatment. The primary outcome is an improvement on a global assessment scale at the end of treatment. Symptoms, quality of life, psychological well-being, and healthcare costs are secondary outcome measures.

DISCUSSION

There have been few studies examining how best to deliver care for functional gut disorders. The MANTRA study will define the clinical and cost benefits of two different models of care for these highly prevalent disorders.

TRIAL REGISTRATION NUMBER

Clinicaltrials.govNCT03078634 Registered on Clinicaltrials.gov, completed recruitment, registered on March 13th 2017. Ethics and Dissemination: Ethical approval has been received by the St Vincent's Hospital Melbourne human research ethics committee (HREC-A 138/16). The results will be disseminated in peer-reviewed journals and presented at international conferences. Protocol version 1.2.

Does Opioid Tapering in Chronic Pain Patients Result in Improved Pain or Same Pain vs Increased Pain at Taper Completion? A Structured Evidence-Based Systematic Review

Objective

To support or refute the hypothesis that opioid tapering in chronic pain patients (CPPs) improves pain or maintains the same pain level by taper completion but does not increase pain.

Methods

Of 364 references, 20 fulfilled inclusion/exclusion criteria. These studies were type 3 and 4 (not controlled) but reported pre/post-taper pain levels. Characteristics of the studies were abstracted into tabular form for numerical analysis. Studies were rated independently by two reviewers for quality. The percentage of studies supporting the above hypothesis was determined.

Results

No studies had a rejection quality score. Combining all studies, 2,109 CPPs were tapered. Eighty percent of the studies reported that by taper completion pain had improved. Of these, 81.25% demonstrated this statistically. In 15% of the studies, pain was the same by taper completion. One study reported that by taper completion, 97% of the CPPs had improved or the same pain, but CPPs had worse pain in 3%. As such, 100% of the studies supported the hypothesis. Applying the Agency for Health Care Policy and Research Levels of Evidence Guidelines to this result produced an A consistency rating.

Conclusions

There is consistent type 3 and 4 study evidence that opioid tapering in CPPs reduces pain or maintains the same level of pain. However, these studies represented lower levels of evidence and were not designed to test the hypothesis, with the evidence being marginal in quality with large amounts of missing data. These results then primarily reveal the need for controlled studies (type 2) to address this hypothesis.

Co-expression of μ and δ opioid receptors by mouse colonic nociceptors

BACKGROUND AND PURPOSE

To better understand opioid signalling in visceral nociceptors, we examined the expression and selective activation of μ and δ opioid receptors by dorsal root ganglia (DRG) neurons innervating the mouse colon.

EXPERIMENTAL APPROACH

DRG neurons projecting to the colon were identified by retrograde tracing. δ receptor-GFP reporter mice, in situ hybridization, single-cell RT-PCR and μ receptor-specific antibodies were used to characterize expression of μ and δ receptors. Voltage-gated Ca²⁺ currents and neuronal excitability were recorded in small diameter nociceptive neurons (capacitance <30 pF) by patch clamp and ex vivo single-unit afferent recordings were obtained from the colon.

KEY RESULTS

In situ hybridization of oprm1 expression in Fast Blue-labelled DRG neurons was observed in 61% of neurons. μ and δ receptors were expressed by 36-46% of colon DRG neurons, and co-expressed by ~25% of neurons. μ and δ receptor agonists inhibited Ca²⁺ currents in DRG, effects blocked by opioid antagonists. One or both agonists inhibited action potential firing by colonic afferent endings. Incubation of neurons with supernatants from inflamed colon segments inhibited Ca²⁺ currents and neuronal excitability. Antagonists of μ, but not δ receptors, inhibited the effects of these supernatant on Ca²⁺ currents, whereas both antagonists inhibited their actions on neuronal excitability.

CONCLUSIONS AND IMPLICATIONS

A significant number of small diameter colonic nociceptors co-express μ and δ receptors and are inhibited by agonists and endogenous opioids in inflamed tissues. Thus, opioids that act at μ or δ receptors, or their heterodimers may be effective in treating visceral pain.

Reduction in pain: Is it worth the gain? The effect of opioids on the GI tract

The use of opioid medications for acute and chronic pain has increased significantly in the past 20 years in the United States. Given the high density of opioid receptors in the gastrointestinal tract, side effects are common in these patients including constipation, dysphagia, bloating, nausea, and vomiting. These side effects, which are experienced by most patients who take opioids, can lead to significant impairment in quality of life. Unlike other side effects from opioids, gastrointestinal side effects do not diminish with continued use, often leading patients to reduce or discontinue their opioid treatment to relieve these side effects. Therefore, physicians must be aware and anticipate potential side effects in patients receiving opioids to ensure appropriate pain management.

Neuromodulators for Functional Gastrointestinal Disorders (Disorders of Gut-Brain Interaction): A Rome Foundation Working Team Report

BACKGROUND & AIMS

Central neuromodulators (antidepressants, antipsychotics, and other central nervous system-targeted medications) are increasingly used for treatment of functional gastrointestinal disorders (FGIDs), now recognized as disorders of gut-brain interaction. However, the available evidence and guidance for the use of central neuromodulators in these conditions is scanty and incomplete. In this Rome Foundation Working Team report, a multidisciplinary team summarized available research evidence and clinical experience to provide guidance and treatment recommendations.

METHODS

The working team summarized the literature on the pharmacology of central neuromodulators and their effects on gastrointestinal sensorimotor function and conducted an evidence-based review on their use for treating FGID syndromes. Because of the paucity of data for FGIDs, we included data for non-gastrointestinal painful disorders and specific symptoms of pain, nausea, and vomiting. This information was combined into a final document comprising a synthesis of available evidence and recommendations for clinical use guided by the research and clinical experience of the experts on the committee.

RESULTS

The evidence-based review on neuromodulators in FGID, restricted by the limited available controlled trials, was integrated with open-label studies and case series, along with the experience of experts to create recommendations using a consensus (Delphi) approach. Due to the diversity of conditions and complexity of treatment options, specific recommendations were generated for different FGIDs. However, some general recommendations include: (1) low to modest dosages of tricyclic antidepressants provide the most convincing evidence of benefit for treating chronic gastrointestinal pain and painful FGIDs and serotonin noradrenergic reuptake inhibitors can also be recommended, though further studies are needed; (2) augmentation, that is, adding a second treatment (adding quetiapine, aripiprazole, buspirone α2δ ligand agents) is recommended when a single medication is unsuccessful or produces side effects at higher dosages; (3) treatment should be continued for 6-12 months to potentially prevent relapse; and (4) implementation of successful treatment requires effective communication skills to improve patient acceptance and adherence, and to optimize the patient-provider relationship.

CONCLUSIONS

Based on systematic and selectively focused review and the consensus of a multidisciplinary panel, we have provided summary information and guidelines for the use of central neuromodulators in the treatment of chronic gastrointestinal symptoms and FGIDs. Further studies are needed to confirm and refine these recommendations.

Opioid misuse in gastroenterology and non-opioid management of abdominal pain

Opioids were one of the earliest classes of medications used for pain across a variety of conditions, but morbidity and mortality have been increasingly associated with their chronic use. Despite these negative consequences, chronic opioid use is increasing worldwide, with the USA and Canada having the highest rates. Chronic opioid use for noncancer pain can have particularly negative effects in the gastrointestinal and central nervous systems, including opioid-induced constipation, narcotic bowel syndrome, worsening psychopathology and addiction. This Review summarizes the evidence of opioid misuse in gastroenterology, including the lack of evidence of a benefit from these drugs, as well as the risk of harm and negative consequences of opioid use relative to the brain-gut axis. Guidelines for opioid management and alternative pharmacological and nonpharmacological strategies for pain management in patients with gastrointestinal disorders are also discussed. As chronic pain is complex and involves emotional and social factors, a multimodal approach targeting both pain intensity and quality of life is best.

Opioid medication use in patients with gastrointestinal diagnoses vs unexplained gastrointestinal symptoms in the US Veterans Health Administration

BACKGROUND

While opioid prescriptions have increased alarmingly in the United States (US), their use for unexplained chronic gastrointestinal (GI) pain (eg, irritable bowel syndrome) carries an especially high risk for adverse effects and questionable benefit.

AIM

To compare opioid use among US veterans with structural GI diagnoses (SGID) and those with unexplained GI symptoms or functional GI diagnoses (FGID), a group for whom opioids have no accepted role.

METHODS

Veterans Health Administration (VHA) administrative data from fiscal year 2012 were used to identify veterans with diagnostic codes recorded for SGID and FGID. This cohort study examined VHA pharmacy data to compare groups receiving ≥ 1 opioid prescription during the year and number of prescriptions filled. Bivariate and multiple logistic regression analyses adjusted for potential confounding factors (demographics, medical diagnoses, social factors) and identified potential mediators (service use, psychiatric comorbidity) of opioid use in these groups.

RESULTS

A greater proportion of veterans with FGID received an opioid prescription during fiscal year 2012 (36.0% of 272 431) compared to only 28.9% of 1 223 744 in the SGID group (Relative Risk [RR] = 1.25). In multivariate logistic regression, personality disorders and drug abuse (OR 1.23 for each group), recent homelessness (OR 1.22), psychotropic medication fills (OR 1.55) and emergency department encounters (OR 1.21) were independently associated with opioid prescription use.

CONCLUSIONS

Despite the potential for adverse consequences, opioids more often are prescribed for veterans with chronic, unexplained GI symptoms compared to those with structural diagnoses. Psychiatric comorbidities and frequent healthcare encounters mediate some of the opioid use risk.

Strategies to Identify and Reduce Opioid Misuse Among Patients with Gastrointestinal Disorders: A Systematic Scoping Review

BACKGROUND

Scoping reviews are preliminary assessments intended to characterize the extent and nature of emerging research evidence, identify literature gaps, and offer directions for future research. We conducted a systematic scoping review to describe published scientific literature on strategies to identify and reduce opioid misuse among patients with gastrointestinal (GI) symptoms and disorders.

METHODS

We performed structured keyword searches to identify manuscripts published through June 2016 in the PubMed MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science databases to extract original research articles that described healthcare practices, tools, or interventions to identify and reduce opioid misuse among GI patients. The Chronic Care Model (CCM) was used to classify the strategies presented.

RESULTS

Twelve articles met the inclusion criteria. A majority of studies used quasi-experimental or retrospective cohort study designs. Most studies addressed the CCM's clinical information systems element. Seven studies involved identification of opioid misuse through prescription drug monitoring and opioid misuse screening tools. Four studies discussed reductions in opioid use by harnessing drug monitoring data and individual care plans, and implementing self-management and opioid detoxification interventions. One study described drug monitoring and an audit-and-feedback intervention to both identify and reduce opioid misuse. Greatest reductions in opioid misuse were observed when drug monitoring, self-management, or audit-and-feedback interventions were used.

CONCLUSION

Prescription drug monitoring and self-management interventions may be promising strategies to identify and reduce opioid misuse in GI care. Rigorous, empirical research is needed to evaluate the longer-term impact of these strategies.

Opioid-Induced Constipation and Bowel Dysfunction: A Clinical Guideline

OBJECTIVE

To formulate timely evidence-based guidelines for the management of opioid-induced bowel dysfunction.

SETTING

Constipation is a major untoward effect of opioids. Increasing prescription of opioids has correlated to increased incidence of opioid-induced constipation. However, the inhibitory effects of opioids are not confined to the colon, but also affect higher segments of the gastrointestinal tract, leading to the coining of the term "opioid-induced bowel dysfunction."

METHODS

A literature search was conducted using Medline, EMBASE, and EMBASE Classic, and the Cochrane Central Register of Controlled Trials. Predefined search terms and inclusion/exclusion criteria were used to identify and categorize relevant papers. A series of statements were formulated and justified by a comment, then labeled with the degree of agreement and their level of evidence as judged by the Strength of Recommendation Taxonomy (SORT) system.

RESULTS

From a list of 10,832 potentially relevant studies, 33 citations were identified for review. Screening the reference lists of the pertinent papers identified additional publications. Current definitions, prevalence, and mechanism of opioid-induced bowel dysfunction were reviewed, and a treatment algorithm and statements regarding patient management were developed to provide guidance on clinical best practice in the management of patients with opioid-induced constipation and opioid-induced bowel dysfunction.

CONCLUSIONS

In recent years, more insight has been gained in the pathophysiology of this "entity"; new treatment approaches have been developed, but guidelines on clinical best practice are still lacking. Current knowledge is insufficient regarding management of the opioid side effects on the upper gastrointestinal tract, but recommendations can be derived from what we know at present.

Opioids in Gastroenterology: Treating Adverse Effects and Creating Therapeutic Benefits

The use of opioid medications on both an acute and chronic basis is ubiquitous in the United States. As opioid receptors densely populate the gastrointestinal tract, symptoms and side effects can be expected in these patients. In the esophagus, dysmotility may result, manifesting with dysphagia and a syndrome indistinguishable from primary achalasia. In the stomach, a marked delay in gastric emptying may occur with postprandial nausea and early satiety. Postoperatively, particularly with abdominal surgery, opioid-induced ileus may ensue. In the colon, opioid-induced constipation is common. A unique syndrome termed narcotic bowel syndrome is characterized by chronic abdominal pain often accompanied by nausea and vomiting in the absence of other identifiable causes. With the recognition of the important role of opioids on gastrointestinal function, novel drugs have been developed that use this physiology. These medications include peripheral acting opioid agonists to treat opioid-induced constipation and combination agonist and antagonists used for diarrhea-predominant irritable bowel syndrome. This review summarizes the most recent data in these areas.

What Is New in Rome IV

Functional gastrointestinal disorders (FGIDs) are diagnosed and classified using the Rome criteria; the criteria may change over time as new scientific data emerge. The Rome IV was released in May 2016. The aim is to review the main changes in Rome IV. FGIDs are now called disorders of gut-brain interaction (DGBI). Rome IV has a multicultural rather than a Western-culture focus. There are new chapters including multicultural, age-gender-women's health, intestinal microenvironment, biopsychosocial, and centrally mediated disorders. New disorders have been included although not truly FGIDs, but fit the new definition of DGBI including opioid-induced gastrointestinal hyperalgesia , opioid-induced constipation , and cannabinoid hyperemesis . Also, new FGIDs based on available evidence including reflux hypersensitivity and centrally mediated abdominal pain syndrome . Using a normative survey to determine the frequency of normal bowel symptoms in the general population changes in the time frame for diagnosis were introduced. For irritable bowel syndrome (IBS) only pain is required and discomfort was eliminated because it is non-specific, having different meanings in different languages. Pain is now related to bowel movements rather than just improving with bowel movements (ie, can get worse with bowel movement). Functional bowel disorders (functional diarrhea , functional constipation , IBS with predominant diarrhea [IBS-D], IBS with predominant constipation [IBS-C ], and IBS with mixed bowel habits ) are considered to be on a continuum rather than as independent entities. Clinical applications such as diagnostic algorithms and the Multidimensional Clinical Profile have been updated. The new Rome IV iteration is evidence-based, multicultural oriented and with clinical applications. As new evidence become available, future updates are expected.

Etiology and Treatment of Pain and Psychosocial Issues in Patients With Inflammatory Bowel Diseases

There is increasing evidence that brain-gut interactions are altered during development of inflammatory bowel diseases (IBDs). Understanding the relationship between the neurobiology, psychological symptoms, and social ramifications of IBD can guide comprehensive care for the whole patient. The most common psychological conditions in patients with IBD are chronic abdominal pain, anxiety, and depression. We review the evidence-based data and rates of these conditions and their respective relationship to IBD and the diagnostic approaches to identify patients with these conditions. Different treatment options for pain and psychosocial conditions are discussed, and new models of team-based IBD care are introduced. Providing the health care provider with tools to diagnose and manage psychological conditions in patients with Crohn's disease or ulcerative colitis is necessary for their total care and should be part of quality-improvement initiatives.

Opioids and GI Motility-Friend or Foe?

OPINION STATEMENT

The use of opioids for the treatment of chronic non-cancer pain is growing at an alarming rate. Opioid-induced bowel dysfunction (OBD) is a common adverse effect of long-term opioid treatment manifesting as constipation, nausea, and vomiting. These effects are primarily mediated by peripheral μ-opioid receptors with resultant altered GI motility and function. As a result, patients may present with opioid-induced constipation (OIC), opioid-induced nausea and vomiting (OINV), and/or narcotic bowel syndrome (NBS). This often leads to decreased quality of life and in many cases, discontinuation of opioid therapy. There is limited evidence to support the use of traditional anti-emetics and laxatives in the treatment of OBD. Tapering the dose of opioids, switching to transdermal application, opioid rotation, or dual-action opioids, such as tapentadol, may be helpful in the treatment of OBD. Novel agents, such as peripherally acting μ-opioid receptor antagonists which target the cause of OIC, show promise in the treatment of OBD and should be considered when conventional laxatives fail. This chapter will review the pathophysiology of OBD, including OINV and OIC, and treatment options available.

Opioidergic effects on enteric and sensory nerves in the lower GI tract: basic mechanisms and clinical implications

Opioids are one of the most prescribed drug classes for treating acute pain. However, chronic use is often associated with tolerance as well as debilitating side effects, including nausea and dependence, which are mediated by the central nervous system, as well as constipation emerging from effects on the enteric nervous system. These gastrointestinal (GI) side effects limit the usefulness of opioids in treating pain in many patients. Understanding the mechanism(s) of action of opioids on the nervous system that shows clinical benefit as well as those that have unwanted effects is critical for the improvement of opioid drugs. The opioidergic system comprises three classical receptors (μ, δ, κ) and a nonclassical receptor (nociceptin), and each of these receptors is expressed to varying extents by the enteric and intestinal extrinsic sensory afferent nerves. The purpose of this review is to discuss the role that the opioidergic system has on enteric and extrinsic afferent nerves in the lower GI tract in health and diseases of the lower GI tract, particularly inflammatory bowel disease and irritable bowel syndrome, and the implications of opioid treatment on clinical outcomes. Consideration is also given to emerging developments in our understanding of the immune system as a novel source of endogenous opioids and the mechanisms underlying opioid tolerance, including the potential influence of opioid receptor splice variants and heteromeric complexes.

The narcotic bowel syndrome: a recent update

OBJECTIVES

The paradoxical development of chronic abdominal pain is an underrecognized side effect of opioid use. Narcotic bowel syndrome (NBS), occurring in a small proportion of chronic opioid users, consists of chronic or intermittent abdominal pain, which often increases in severity despite continued or escalating dosages of opioids prescribed to relieve pain.

METHODS

A PubMed search was conducted using terms such as "narcotic bowel syndrome" and "opioid hyperalgesia" through January 2014.

RESULTS

Abdominal pain is the defining symptom of NBS and is thought to be mediated by central nervous system dysfunction; it should be distinguished from the peripheral side effects of opioids, such as nausea, bloating, intermittent vomiting, abdominal distension, and constipation. This latter cluster of symptoms is called opioid bowel dysfunction, although it may co-occur with NBS. Hypothesized mechanisms of the central effects of opioids on nociception in NBS include spinal cord inflammation and dysfunction in opioid receptor activity and related neuroanatomical substrates. With continued use, ∼6% of patients taking narcotics chronically will develop NBS, with profound consequences in terms of daily function. The primary management paradigm for NBS is a structured opioid withdrawal program accompanied by centrally acting adjunctive therapy comprising antidepressants, benzodiazepines, and clonidine to target pain, anxiety, and depression, and prevent withdrawal effects, in addition to peripherally acting agents such as laxatives (e.g., osmotic laxatives and chloride channel activators) to control transient constipation. Such structured withdrawal programs have been prospectively evaluated in small clinical trials and have met with considerable success in the short term.

CONCLUSIONS

Because rates of NBS are likely to rise, integrated intensive pharmacotherapy and psychosocial interventions are needed to help patients with NBS go off and stay off opioids. These programs will likely also reduce comorbid psychopathology and lead to adequate pain control and improved quality of life.

Centrally Mediated Disorders of Gastrointestinal Pain

Centrally Mediated Abdominal Pain Syndrome (CAPS), formerly known as Functional Abdominal Pain Syndrome, can be distinguished from other functional GI disorders by its strong central component and relative independence from motility disturbances. CAPS is a result of central sensitization with disinhibition of pain signals rather than increased peripheral afferent excitability. A newly described condition, Narcotic Bowel Syndrome (NBS)/Opioid-Induced GI Hyperalgesia, is characterized by the paradoxical development of or increases in abdominal pain associated with continuous or increasing dosages of opioids. Patients only have relief when opioids are withdrawn. We define both conditions in the context of epidemiology, pathophysiology, clinical evaluation and treatment, emphasizing the importance of a physician-patient relationship in all aspects of care.

Achalasia and chronic opiate use: innocent bystanders or associated conditions?

High-resolution manometry identifies three subtypes of achalasia. However, type 3 differs from classic achalasia. Although opiates affect esophageal motility, opiate use and achalasia have not been studied. Patients with a new diagnosis of achalasia at Mayo Clinic Rochester between June 1, 2012 and January 3, 2014 were identified. Clinical records were reviewed to assess symptoms, opiate use, and therapy. Fifty-six patients with achalasia were identified, 14 (25%) were on opiates. Opiate prescription was unrelated to achalasia in all cases, with chronic back and joint pain constituting the majority. Of patients on opiates, five (36%) had type 3 achalasia compared with four (10%) not on opiates (P = 0.02). No patients on opiates had type 1 achalasia. Clinical presentation did not differ with opiates, although those on opiates were more likely to report chest pain (39 vs. 14%, P = 0.05) and less likely to have esophageal dilation (62 vs. 82%, P = 0.13), none with greater than 5-cm diameter. Contractile vigor was greater with opiate use, with distal contractile integral of 7149 versus 2615.5 mmHg/cm/second (P = 0.08). Treatment response was inferior on opiates, with persistent symptoms in 22% compared with 3% without opiates (P = 0.06). Opiate use is common in type 3 achalasia, with the majority of patients on opiates. No patients on opiates were diagnosed with type 1 achalasia. Manometric findings of type 3 achalasia mimic those induced by opiates, suggesting a physiologic mechanism for opiate induced type 3 achalasia. Treatment outcome is inferior with opiates, with opiate cessation perhaps preferable. Further studies assessing opiate use and achalasia are needed.

Endogenous opiates and behavior: 2013

This paper is the thirty-sixth consecutive installment of the annual review of research concerning the endogenous opioid system. It summarizes papers published during 2013 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior, and the roles of these opioid peptides and receptors in pain and analgesia; stress and social status; tolerance and dependence; learning and memory; eating and drinking; alcohol and drugs of abuse; sexual activity and hormones, pregnancy, development and endocrinology; mental illness and mood; seizures and neurologic disorders; electrical-related activity and neurophysiology; general activity and locomotion; gastrointestinal, renal and hepatic functions; cardiovascular responses; respiration and thermoregulation; and immunological responses.

Avoiding analgesic escalation and excessive healthcare utilization in severe irritable bowel syndrome: a role for intramuscular anticholinergics?

OBJECTIVES

In patients with severe irritable bowel syndrome (IBS), abdominal pain can be the predominant symptom impacting on all aspects of their lives and resulting in excessive healthcare utilization. Furthermore, the use of analgesics can become excessive in this group of patients, sometimes leading to opiate dependency. Typically, the pain is often described as spastic in nature and we have speculated that parenteral anticholinergics might provide effective relief when all other measures have failed. For several years, we have therefore been asking general practitioners to consider teaching such patients to administer intramuscular hyoscine butylbromide for pain episodes and this study is an audit of this approach.

METHODS

Patients in whom the use of intramuscular hyoscine butylbromide had been recommended to their general practitioner in the last three years were interviewed over the telephone in order to document the efficacy of this approach as well as any potential disadvantages.

RESULTS

A total of 122 general practitioners were advised to try this approach, with 58 agreeing to teach the technique and prescribe the medication. Of the 58 patients who used the medication, 50 (86%) found it gave them pain relief, which was complete in six (10%), substantial in 36 (62%) and mild in eight (14%), with 15 (26%) decreasing the use of analgesics and 13 (32%) of the 41 taking opiates able to reduce or stop them completely. Side effects were few and largely consisted of those associated with anticholinergics. Only four patients stopped medication because of side effects and no major skin reactions were reported.

CONCLUSIONS

The use of intramuscular hyoscine butylbromide shows promise in the management of IBS when severe unmanageable abdominal pain is a major problem. This approach appears to be safe and has the potential to reduce analgesic escalation, opiate dependency and attendances at accident and emergency departments.

Narcotic bowel syndrome and opioid-induced constipation

Prescription opioid use for chronic non-cancer pain has reached epidemic levels in the USA. With this increased use is the recognition of serious opioid-related gastrointestinal complications such as narcotic bowel syndrome (NBS) and opioid-induced constipation (OIC). NBS consists of a paradoxical worsening of abdominal pain with escalating doses of opioids and is likely mediated by the central nervous system. Therapy requires an intensive multidisciplinary approach to detoxification. OIC is the most common gastrointestinal side effect of opioids. Several novel therapeutics are available to treat OIC that fails to respond to laxative therapy. This review will summarize recent findings on the pathophysiology and treatment approaches to NBS and OIC with a focus on controversies about diagnosis and intervention.

Diagnosis and treatment of narcotic bowel syndrome

With increased prescription of opioids has come increased recognition of adverse consequences, including narcotic bowel syndrome (NBS). Characterized by incompletely controlled abdominal pain despite continued or increasing doses of opioids, NBS is estimated to occur in 4.2-6.4% of patients chronically taking opioids. Patients with NBS have a high degree of comorbid psychiatric illness, catastrophizing and disability; comorbid substance abuse must also be considered among this population. NBS should be distinguished from opioid-induced bowel disorder, which results from the effects of opioids on gastrointestinal motility and secretion. By contrast, the mechanisms of NBS are probably centrally mediated and include glial cell activation, bimodal opioid modulation in the dorsal horn, descending facilitation of pain and the glutaminergic system. Few treatments have been rigorously studied. A trial of opioid detoxification resulted in complete detoxification for the vast majority of patients with reduction in pain symptoms; however, despite improvement in pain, approximately half of patients returned to opioid use within 3 months. Improved strategies are needed to identify patients who will respond to detoxification and remain off opioids. Comorbid psychiatric and substance abuse disorders are barriers to durable response after detoxification and should be actively sought out and treated accordingly. An effective patient-physician relationship is essential.

The two sides of opioids in cyclical vomiting syndrome

Background:

Cyclical vomiting syndrome is increasingly recognized in adults, with recent reports suggesting ‘coalescing attacks’ in one third of the patients. We hypothesized that the common need for opioid treatment may contribute to coalescing attacks through development of opioid dependence and withdrawal, triggering cyclical vomiting syndrome.

Aim:

This study was to review iatrogenic opioid dependence as the potential cause for triggering cyclical vomiting syndrome.

Materials and Methods:

A retrospective review was performed to identify patients treated for cyclical vomiting syndrome by a single physician between Jan and December of 2010. Demographic data, clinical presentation, treatment, cumulative opioid prescription during hospitalizations and emergency room visits and days of inpatient stay were abstracted from the chart.

Results:

Forty-one patients (mean age 37.5.6 ± 2.6 years; 66% female) were seen within this timeframe. In eleven patients (27%) with ongoing opioid use, the initial cyclical illness had progressed and eventually coalesced. A cohort of 23 patients was followed for at least 6 months (12.3 ± 1.7 months). The best single predictor of repeat hospitalizations was the cumulative opioid dosage.

Conclusion:

Continued use of opioid therapy is a poor prognostic marker of cyclical vomiting syndrome and may contribute to disease coalescence, with dependence and withdrawal triggering recurrent episodes.