Clinical effects of STW 5 (Iberogast) are not based on acceleration of gastric emptying in patients with functional dyspepsia and gastroparesis

Review article: current treatment options and management of functional dyspepsia

BACKGROUND

Functional dyspepsia (FD), a common functional gastrointestinal disorder, is defined by the Rome III criteria as symptoms of epigastric pain or discomfort (prevalence in FD of 89-90%), postprandial fullness (75-88%), and early satiety (50-82%) within the last 3 months with symptom onset at least 6 months earlier. Patients cannot have any evidence of structural disease to explain symptoms and predominant symptoms of gastroesophageal reflux are exclusionary. Symptoms of FD are non-specific and the pathophysiology is diverse, which explains in part why a universally effective treatment for FD remains elusive.

AIM

To present current management options for the treatment of FD (therapeutic gain/response rate noted when available).

RESULTS

The utility of Helicobacter pylori eradication for the treatment of FD is modest (6-14% therapeutic gain), while the therapeutic efficacy of proton pump inhibitors (PPI) (7-10% therapeutic gain), histamine-type-2-receptor antagonists (8-35% therapeutic gain), prokinetic agents (18-45%), tricyclic antidepressants (TCA) (response rates of 64-70%), serotonin reuptake inhibitors (no better than placebo) is limited and hampered by inadequate data. This review discusses dietary interventions and analyses studies involving complementary and alternative medications, and psychological therapies.

CONCLUSIONS

A reasonable treatment approach based on current evidence is to initiate therapy with a daily PPI in H. pylori-negative FD patients. If symptoms persist, a therapeutic trial with a tricyclic antidepressant may be initiated. If symptoms continue, the clinician can possibly initiate therapy with an anti-nociceptive agent, a prokinetic agent, or some form of complementary and alternative medications, although evidence from prospective studies to support this approach is limited.

Dyspepsia: organic versus functional

Dyspepsia is the medical term for difficult digestion. It consists of various symptoms in the upper abdomen, such as fullness, discomfort, early satiation, bloating, heartburn, belching, nausea, vomiting, or pain. The prevalence of dyspepsia in the western world is approximately 20% to 25%. Dyspepsia can be divided into 2 main categories: "organic" and "functional dyspepsia" (FD). Organic causes of dyspepsia are peptic ulcer, gastroesophageal reflux disease, gastric or esophageal cancer, pancreatic or biliary disorders, intolerance to food or drugs, and other infectious or systemic diseases. Pathophysiological mechanisms underlying FD are delayed gastric emptying, impaired gastric accommodation to a meal, hypersensitivity to gastric distension, altered duodenal sensitivity to lipids or acids, altered antroduodenojenunal motility and gastric electrical rhythm, unsuppressed postprandial phasic contractility in the proximal stomach, and autonomic nervous system-central nervous system dysregulation. Pathogenetic factors in FD are genetic predisposition, infection from Helicobacter pylori or other organisms, inflammation, and psychosocial factors. Diagnostic evaluation of dyspepsia includes upper gastrointestinal endoscopy, abdominal ultrasonography, gastric emptying testing (scintigraphy, breath test, ultrasonography, or magnetic resonance imaging), and gastric accommodation evaluation (magnetic resonance imaging, ultrasound, single-photon emission computed tomography, and barostat). Antroduodenal manometry can be used for the assessment of the myoelectrical activity of the stomach, whereas sensory function can be evaluated with the barostat, tensostat, and satiety test. Management of FD includes general measures, acid-suppressive drugs, eradication of H. pylori, prokinetic agents, fundus-relaxing drugs, antidepressants, and psychological interventions. This review presents an update on the diagnosis of patients presenting with dyspepsia, with an emphasis on the pathophysiological and pathogenetic mechanisms of FD and the differential diagnosis with organic causes of dyspepsia. The management of uninvestigated and FD, as well as the established and new pharmaceutical agents, is also discussed.

Therapeutic strategies for the treatment of dyspepsia

IMPORTANCE OF THE FIELD

Dyspeptic symptoms are highly prevalent in the population and represent a major burden for healthcare systems. The ROME III criteria address and define two separate entities of functional dyspepsia: epigastric pain syndrome and postprandial distress syndrome. The etiology of dyspeptic symptoms is heterogeneous, underlying mechanisms are poorly understood and symptomatic improvement after drug therapy is often incomplete.

AREAS COVERED IN THIS REVIEW

This review of the literature included Medline data being published in the field of functional dyspepsia and different therapies.

WHAT THE READER WILL GAIN

The reader will gain a current, unbiased understanding of the pathophysiological mechanisms underlying functional dyspepsia and of the therapeutic regimens based on randomized, controlled trials and on the meta-analyses that have been published on different therapeutic agents.

TAKE HOME MESSAGE

Before starting medical treatment, a careful physical examination should exclude 'alarm symptoms'. Laboratory data, ultrasound and endoscopy are recommended in patients older than 45 - 55 years (depending on the guidelines being used). In areas with a high prevalence of Helicobacter pylori, the initial strategy includes 'test and treat' for H. pylori in addition to empiric acid suppressive therapy. Many studies have focused on the role of gastrointestinal dysmotility and hypersensitivity for dyspepsia with inconclusive results. Further therapeutic medical strategies include prokinetics, herbal preparations and psycho-/neurotopic drugs as well as additional psycho- or hypnotherapy.

Gastroparesis: pathogenesis, diagnosis and management

Gastroparesis is a prevalent condition that produces symptoms of delayed gastric emptying in the absence of physical blockage. The most common etiologies of gastroparesis are idiopathic, diabetic, and postsurgical disease, although some cases stem from autoimmune, paraneoplastic, neurologic or other conditions. Histologic examination of gastric tissues from patients with severe gastroparesis reveals heterogeneous and inconsistent defects in the morphology of enteric neurons, smooth muscle and interstitial cells of Cajal, and increased levels of inflammatory cells. Diagnosis is most commonly made by gastric emptying scintigraphy; however, wireless motility capsules and nonradioactive isotope breath tests have also been validated. A range of treatments have been used for gastroparesis including dietary modifications and nutritional supplements, gastric motor stimulatory or antiemetic medications, endoscopic or surgical procedures, and psychological interventions. Most treatments have not been subjected to controlled testing in patients with gastroparesis. The natural history of this condition is poorly understood. Active ongoing research is providing important insights into the pathogenesis, diagnosis, treatment and outcomes of this disease.

Gastroparesis: approach, diagnostic evaluation, and management

Gastroparesis is a chronic motility disorder of the stomach that involves delayed emptying of solids and liquids, without evidence of mechanical obstruction. Although no cause can be determined for the majority of cases, the disease often develops as a complication of abdominal surgeries or because of other underlying disorders, such as diabetes mellitus or scleroderma. The pathophysiology behind delayed gastric emptying is still not well-understood, but encompasses abnormalities at 3 levels--autonomic nervous system, smooth muscle cells, and enteric neurons. Patients will often cite nausea, vomiting, postprandial fullness, and early satiety as their most bothersome symptoms on history and physical examination. Those that present with severe disease may already have developed complications, such as the formation of bezoars or masses of undigested food. In patients suspected of gastroparesis, diagnostic evaluation requires an initial upper endoscopy to rule out mechanical causes, followed by a gastric-emptying scintigraphy for diagnosis. Other diagnostic alternatives would be wireless capsule motility, antroduodenal manometry, and breath testing. Once gastroparesis is diagnosed, dietary modifications, such as the recommendation of more frequent and more liquid-based meals, are encouraged. Promotility medications like erythromycin and antiemetics like prochlorperazine are offered for symptomatic relief. These agents may be frequently changed, as the right combination of effective medications will vary with each individual. In patients who are refractory to pharmacologic treatment, more invasive options, such as intrapyloric botulinum toxin injections, placement of a jejunostomy tube, or implantation of a gastric stimulator, are considered. Future areas of research are based on current findings from clinical studies. New medications, such as hemin therapy, are emerging because of a better understanding of the pathophysiology behind gastroparesis, and present treatment options, such as gastric electric stimulation, are evolving to be more effective. Regenerative medicine and stem cell-based therapies also hold promise for gastroparesis in the near future.

Gastroduodenal motility

PURPOSE OF REVIEW

Abnormalities of gastroduodenal motility are considered key players in the pathogenesis of upper gastrointestinal symptoms in disorders such as functional dyspepsia and gastroparesis. Abnormalities of sensory control are considered another important factor that contributes to symptom generation. This review summarizes recent progress in our understanding of gastroduodenal motility and sensitivity in health and in disease.

RECENT FINDINGS

Although gastric and small intestinal motility remain an important focus of research, including the application of the SmartPill (SmartPill Corp., Buffalo, New York, USA) wireless motility monitoring capsule, duodenal sensitivity and low-grade duodenal inflammation are new areas of interest in the pathogenesis of functional dyspepsia. A number of genetic polymorphisms associated with functional dyspepsia are being investigated, but large-scale studies are still lacking. Central processing of visceral stimuli, and its role in the pathogenesis of functional dyspepsia, is another important emerging topic. Therapeutic studies have reported on novel pharmacological approaches in functional dyspepsia and gastroparesis, as well as gastric electrical stimulation in the treatment of refractory gastroparesis.

SUMMARY

There is gradual progress in our understanding of the pathogenesis of gastroduodenal symptoms. Areas of recent advances including the recognition of low-grade duodenal inflammation, the role of central nervous system processing in visceral hypersensitivity and the exploration of novel pharmacotherapeutic approaches.

Gastroparesis and functional dyspepsia: excerpts from the AGA/ANMS meeting

BACKGROUND

Despite the relatively high prevalence of gastroparesis and functional dyspepsia, the aetiology and pathophysiology of these disorders remain incompletely understood. Similarly, the diagnostic and treatment options for these two disorders are relatively limited despite recent advances in our understanding of both disorders.

PURPOSE

This manuscript reviews the advances in the understanding of the epidemiology, pathophysiology, diagnosis, and treatment of gastroparesis and functional dyspepsia as discussed at a recent conference sponsored by the American Gastroenterological Association (AGA) and the American Neurogastroenterology and Motility Society (ANMS). Particular focus is placed on discussing unmet needs and areas for future research.