Efficacy of psychotropic drugs in functional dyspepsia: systematic review and meta-analysis

Functional dyspepsia and duodenal eosinophilia: A new model

Functional dyspepsia (FD) is a highly prevalent disorder that affects more than 10% of the population. In the past decade, the theoretical underpinning of the concept of FD has begun to change, in light of new data on the underlying pathophysiological mechanisms of this disorder, with a focus on the duodenum. The Rome IV criteria, published in 2016, note that gastroesophageal reflux disease and irritable bowel syndrome overlap with FD more than expected by chance, suggesting that they may be part of the same disease spectrum. Infection by Helicobacter pylori (H. pylori) may explain a minority of cases of FD and in the Rome IV criteria H. pylori-associated dyspepsia (defined as symptom relief after eradication therapy) is considered a separate entity. Duodenal inflammation characterized by increased eosinophils and in some cases mast cells, may impair the intestinal barrier. Post-infectious gastroenteritis is now an established risk factor for FD. Other risk factors may include atopy, owning herbivore pets and exposure to antibiotics, together with gastroduodenal microbiome disturbances. Small bowel homing T cells and increased cytokines in the circulation occur in FD, correlating with slow gastric emptying, and a possible association with autoimmune rheumatological disease supports background immune system activation. A genetic predisposition is possible. FD has been linked to psychological disorders, but in some cases psychological distress may be driven by gut mechanisms. Therapeutic options are limited and, aside from responders to H. pylori eradication, provide only modest and temporary relief. Advances in understanding FD may alter clinical practice, and the treatment of duodenal inflammation or microbiome alterations may lead to a cure for a subset of these patients in the future.

Functional dyspepsia

Functional dyspepsia is one of the most prevalent functional gastrointestinal disorders. Functional dyspepsia comprises three subtypes with presumed different pathophysiology and aetiology: postprandial distress syndrome (PDS), epigastric pain syndrome (EPS) and a subtype with overlapping PDS and EPS features. Functional dyspepsia symptoms can be caused by disturbed gastric motility (for example, inadequate fundic accommodation or delayed gastric emptying), gastric sensation (for example, sensations associated with hypersensitivity to gas and bloating) or gastric and duodenal inflammation. A genetic predisposition is probable but less evident than in other functional gastrointestinal disorders, such as irritable bowel syndrome (IBS). Psychiatric comorbidity and psychopathological state and trait characteristics could also play a part, although they are not specific to functional dyspepsia and are less pronounced than in IBS. Possible differential diagnoses include Helicobacter pylori infection and peptic ulceration. Pharmacological therapy is mostly based on the subtype of functional dyspepsia, such as prokinetic and fundus-relaxing drugs for PDS and acid-suppressive drugs for EPS, whereas centrally active neuromodulators and herbal drugs play a minor part. Psychotherapy is effective only in a small subset of patients, whereas quality of life can be severely affected in nearly all patients. Future therapies might include novel compounds that attempt to treat the underlying gastric and duodenal inflammation.

Functional dyspepsia and gastroparesis

PURPOSE OF REVIEW

This review summarizes recent progress in the epidemiology, pathophysiology and treatment of functional dyspepsia and gastroparesis.

RECENT FINDINGS

The definition of functional dyspepsia and its subgroups has been revised in the recent Rome IV consensus. In gastroparesis, the symptom pattern and its similarities and differences from functional dyspepsia have been a focus of recent research. In functional dyspepsia, pathophysiological research continued to evaluate gastric sensorimotor dysfunctions, but low-grade inflammatory changes and loss of mucosal integrity in the duodenum is a new topic of intense research. Treatment advances include new prokinetics such as acotiamide and the ghrelin receptor agonist relamorelin. The efficacy of tricyclic antidepressants was recently reviewed and mirtazapine is a new agent used in the treatment of functional dyspepsia and gastroparesis. In gastroparesis, research has focused on the role of macrophages in loss of interstitial cells of Cajal, and on the role of pyloric resistance as a target for therapy, using botulinum toxin injection and gastric per-endoscopic pyloric myotomy.

SUMMARY

The functional dyspepsia definition and subgrouping were updated in the Rome IV consensus. Research focuses on duodenal mucosal alterations in functional dyspepsia and pyloric resistance in gastroparesis. New treatments include novel prokinetics and pylorus-directed interventions.

The management of functional dyspepsia in clinical practice: what lessons can be learnt from recent literature?

Functional dyspepsia is a prevalent functional gastrointestinal disorder that can significantly erode the quality of life of sufferers and places a major cost burden on healthcare services. In this article, we review the recent literature, selecting the information we consider relevant since it has changed our clinical management of patients with functional dyspepsia.

White Paper AGA: Functional Dyspepsia

Functional dyspepsia remains a major challenge for clinicians with no approved drugs available in the Western World. In October 2016, a meeting was held in Washington, DC, sponsored by the American Gastroenterological Association's Center for Diagnostics and Therapeutics, which included members of the Food and Drug Administration (FDA) and the pharmaceutical industry, experts in FD, and representatives of patient organizations. This white paper summarizes our current status, progress with a validated patient reported outcome instrument in functional dyspepsia, future directions and needs.

ACG and CAG Clinical Guideline: Management of Dyspepsia

We have updated both the American College of Gastroenterology (ACG) and the Canadian Association of Gastroenterology (CAG) guidelines on dyspepsia in a joint ACG/CAG dyspepsia guideline. We suggest that patients ≥60 years of age presenting with dyspepsia are investigated with upper gastrointestinal endoscopy to exclude organic pathology. This is a conditional recommendation and patients at higher risk of malignancy (such as spending their childhood in a high risk gastric cancer country or having a positive family history) could be offered an endoscopy at a younger age. Alarm features should not automatically precipitate endoscopy in younger patients but this should be considered on a case-by-case basis. We recommend patients <60 years of age have a non-invasive test Helicobacter pylori and treatment if positive. Those that are negative or do not respond to this approach should be given a trial of proton pump inhibitor (PPI) therapy. If these are ineffective tricyclic antidepressants (TCA) or prokinetic therapies can be tried. Patients that have an endoscopy where no pathology is found are defined as having functional dyspepsia (FD). H. pylori eradication should be offered in these patients if they are infected. We recommend PPI, TCA and prokinetic therapy (in that order) in those that fail therapy or are H. pylori negative. We do not recommend routine upper gastrointestinal (GI) motility testing but it may be useful in selected patients.

Fluoxetine for Maintenance of Remission and to Improve Quality of Life in Patients with Crohn's Disease: a Pilot Randomized Placebo-Controlled Trial

BACKGROUND AND AIMS

Previous studies have shown that antidepressants reduce inflammation in animal models of colitis. The present trial aimed to examine whether fluoxetine added to standard therapy for Crohn's disease [CD] maintained remission, improved quality of life [QoL] and/or mental health in people with CD as compared to placebo.

METHODS

A parallel randomized double-blind placebo controlled trial was conducted. Participants with clinically established CD, with quiescent or only mild disease, were randomly assigned to receive either fluoxetine 20 mg daily or placebo, and followed for 12 months. Participants provided blood and stool samples and completed mental health and QoL questionnaires. Immune functions were assessed by stimulated cytokine secretion [CD3/CD28 stimulation] and flow cytometry for cell type. Linear mixed-effects models were used to compare groups.

RESULTS

Of the 26 participants, 14 were randomized to receive fluoxetine and 12 to placebo. Overall, 14 [54%] participants were male. The mean age was 37.4 [SD=13.2] years. Fluoxetine had no effect on inflammatory bowel disease activity measured using either the Crohn's Disease Activity Index [F(3, 27.5)=0.064, p=0.978] or faecal calprotectin [F(3, 32.5)=1.08, p=0.371], but did have modest effects on immune function. There was no effect of fluoxetine on physical, psychological, social or environmental QoL, anxiety or depressive symptoms as compared to placebo [all p>0.05].

CONCLUSIONS

In this small pilot clinical trial, fluoxetine was not superior to placebo in maintaining remission or improving QoL. [ID: ACTRN12612001067864.].

Research progress on functional dyspepsia

Functional dyspepsia (FD) is considered to be a series of integrated responses to dysfunction of the brain-gut axis caused by a combination of biological factors and socio-psychological factors. Gastrointestinal motility disorder and mental emotional disorder are important factors leading to the development of FD, and abnormal function of the brain-gut axis is the core mechanism of FD pathogenesis. The high incidence of FD has caused a high degree of attention. In this paper, we will review the latest advances in the understanding of the pathogenesis of FD and in its treatment.

Nutritional habits in functional dyspepsia and its subgroups: a comparative study

OBJECTIVE

Research data demonstrating nutritional habits of functional dyspepsia (FD) patients are very limited. This is the first study to evaluate nutritional habits in FD subgroups according to Rome III criteria. Our aim was to evaluate nutritional habits of FD patients and determine the food items that may provoke a dyspepsia symptom.

METHODS

A total of 168 adults with FD and 135 healthy control subjects participated in the study. FD subjects were divided into epigastric pain syndrome (EP-FD), postprandial distress syndrome (PS-FD), mixed (MX-FD) subgroups according to Rome Criteria III. Subjects completed a questionnaire that included a short-form food frequency questionnaire. Furthermore, subjects were asked to list the food items that were causing a dyspepsia symptom.

RESULTS

Functional dyspepsia subjects had a slightly higher BMI (26.1 ± 4.97 kg/m(2)) than control subjects (24.6 ± 4.08 kg/m(2)). The most common symptom triggering foods among all the FD groups were fried and fatty foods (27.1%), hot spices (26.4%), and carbonated drinks (21.8%). In FD subgroups, carbonated drinks were more likely to cause a symptom in PS-FD group (37.3%) than MX-FD (25.7%) and EP-FD (22.1%) groups. There was no difference in frequency of main meals and snacks among any of the groups.

CONCLUSION

Fatty and spicy foods and carbonated drinks were the most common symptom triggering food items in FD group. In subgroups, carbonated drinks and legumes were more likely to cause a symptom in PS-FD. Removing these food items during the course of treatment might help alleviate the symptoms.