A double-blind, randomized, placebo-controlled trial of itopride (100 and 200 mg three times daily) on gastric motor and sensory function in healthy volunteers

A double-blind randomized, multicenter, placebo-controlled study of itopride in functional dyspepsia postprandial distress syndrome

BACKGROUND

Itopride, a mixed D2 antagonist and cholinesterase inhibitor, has prokinetic effects on gastric motility. The Leuven Postprandial Distress Scale is a validated patient-reported outcome instrument for functional dyspepsia (FD) postprandial distress syndrome (PDS). We aimed to use the LPDS to assess treatment outcome in PDS and PDS/EPS (epigastric pain syndrome).

METHODS

Patients with PDS, with or without non-predominant EPS symptoms, were enrolled in an 8-week double-blind placebo-controlled multi-center trial with itopride (100 mg t.i.d.). Patients completed LPDS diaries and questionnaires to assess treatment response. Mann-Whitney test and mixed models were used.

RESULTS

One hundred patients (79% females, 39.1 ± 1.5 yo) were included. No significant difference was observed between treatment arms (p = 0.6). Compared to baseline, itopride treatment significantly improved the LPDS score (p = 0.001) and all individual symptoms (p < 0.0001). In the placebo arm, this was only the case for belching and epigastric pain (p < 0.05). In an exploratory analysis, outcomes in "pure" PDS (n = 45) and overlapping PDS/EPS (n = 55) patients were assessed and showed that the latter subgroup has the largest benefit with itopride compared to placebo (p = 0.03).

CONCLUSION

Using the LPDS score in a pilot controlled trial in FD, itopride shows no therapeutic benefit over placebo after 8 weeks of treatment. In an exploratory post hoc analysis, itopride but not placebo was associated with improvement of symptoms compared to baseline, and this was most prominent in patients with overlapping PDS/EPS. The efficacy of itopride in this subgroup needs to be evaluated in a large study using the same outcome measure. (clinialtrials.org ref.: NCT04647955).

Prokinetic Agents

Gastrointestinal (GI) prokinetic agents are drugs that increase GI motility and promote the movement of contents in the GI tract by amplifying and controlling the contraction of GI smooth muscle. Currently used prokinetics increase GI motility by acting as a dopamine D₂ receptor antagonist (e.g., metoclopramide, domperidone, levosulpiride) and 5-HT₄ receptor agonist (e.g., mosapride, prucalopride). Some prokinetics also have a cholinesterase inhibitory property (e.g., itopride), and herb-derived prokinetics (e.g., motilitone) affect multiple receptors. Depending on the type and distribution of receptors on which the prokinetics bind, the effect(s) may be regional or throughout the GI tract. Most prokinetics have been used for functional dyspepsia and gastroparesis because they mainly affect upper GI motility. However, prucalopride, a highly selective 5-HT₄ receptor agonist, is used primarily to treat chronic constipation and pseudo-obstruction. Dopamine D₂ receptor antagonists also inhibit the D₂ receptor in the medulla oblongata chemoreceptor trigger zone; therefore, they can treat nausea and vomiting. However, short term use of dopamine D₂ antagonists at an appropriate dose is recommended because of their potential for central nervous system side effects by penetrating the blood-brain barrier. It is necessary to know the mechanism of action, each clinical trial’s characteristics, and the side effects of prokinetics to obtain the best clinical outcomes. This article aims to summarize the results of clinical studies related to the impact of currently available prokinetic agents in Korea on GI motility.

Review article: treatment options for functional dyspepsia

BACKGROUND

Functional dyspepsia, consisting of epigastric pain syndrome and postprandial distress syndrome, is a prevalent functional gastrointestinal disorder. To date, only limited treatment options are available and conflicting results in terms of efficacy have been reported. Consequently, nonpharmacological treatment options are increasingly being explored for functional dyspepsia.

AIM

To provide an overview of current pharmacological and nonpharmacological treatment options for functional dyspepsia.

METHODS

A literature search was conducted on Pubmed and other sources to identify relevant studies.

RESULTS

Acid suppressive therapy reduced symptoms in 30%-70% of the patients, with higher benefit in epigastric pain syndrome and superior effectiveness for proton pump inhibitors compared to H₂ -antagonists. Prokinetic agents, primarily used to treat postprandial distress syndrome, showed variable efficiency: 59%-81% responder rate for dopamine receptor antagonists, 32%-91% for serotonin-4-receptor agonists and 31%-80% for muscarinic receptor antagonists. H Pylori eradication, recommended in infected patients, was effective in 24%-82%. Refractory symptoms are addressed with neuromodulators. However, their efficacy in functional dyspepsia remains incompletely elucidated, available data showing symptom reduction in 27%-71% of the patients. Regarding herbal agents, peppermint oil reduced symptoms in 66%-91%, rikkunshito in 29%-34% and iberogast in 20%-95%. Lastly, acupuncture, cognitive behavioural therapy and hypnotherapy may help to provide symptom control, but research on their efficacy remains sparse.

CONCLUSIONS

None of the available therapies is effective in the majority of patients without being associated with major side effects. Developing new treatment options is challenging due to the heterogeneity of functional dyspepsia, the lack of readily identified target mechanisms and the poor association between pathophysiological disturbances and symptoms.

Influence of itopride and domperidone on gastric tone and on the perception of gastric distention in healthy subjects

OBJECTIVE

Itopride, a prokinetic with dopamine D2-antagonistic and cholinesterase inhibitor properties, is used for treating functional dyspepsia (FD) patients. However, the effects of itopride on sensitivity to gastric distention and impaired gastric accommodation, major pathophysiological mechanisms of FD, are unknown. Our aim was to evaluate the effect of itopride on gastric distention and on gastric accommodation in healthy volunteers, compared to placebo and domperidone.

METHODS

Fifteen healthy volunteers (6 male, mean age 28.3 ± 5.8) were studied after pretreatment for 2 days tid with placebo (P), itopride 50 mg (I50), itopride 100 mg (I100), or domperidone 10 mg (D10) in a placebo-controlled, double-blind cross-over design. A gastric barostat study was performed to assess gastric compliance, sensitivity to gastric distention, and gastric accommodation. Symptoms were evaluated by visual analogue scales and perception scores.

RESULTS

I50, I100, and D10 did not influence gastric compliance and sensitivity compared to placebo. No significant differences in accommodation were observed after I100 compared to P. Preprandial intragastric volumes were similar with D10, I50, or placebo (respectively, 244 ± 21, 225 ± 23, and 261 ± 36 mL, NS). However, postprandial gastric volumes were lower after I50 compared to placebo (303 ± 34 vs. 448 ± 50 mL, P < 0.01). Gastric accommodation was significantly reduced after D10 (90 ± 26 mL) and I50 (78 ± 25 mL) compared to placebo (186 ± 37 mL, P < 0.05, and P < 0.01).

CONCLUSION

In healthy subjects, itopride and domperidone do not alter gastric compliance or sensitivity. I50 and D10 three times daily, but not I100, decrease meal-related gastric accommodation.

Itopride for gastric volume, gastric emptying and drinking capacity in functional dyspepsia

AIM

To study the effect of itopride on gastric accommodation, gastric emptying and drinking capacity in functional dyspepsia (FD).

METHODS

Randomized controlled trial was conducted to check the effect of itopride on gastric accommodation, gastric emptying, capacity of tolerating nutrient liquid and symptoms of FD. We recruited a total of 31 patients having FD on the basis of ROME III criteria. After randomization, itopride was received by 15 patients while 16 patients received placebo. Gastric accommodation was determined using Gastric Scintigraphy. ¹³C labeled octanoic breadth test was performed to assess gastric emptying. Capacity of tolerating nutrient liquid drink was checked using satiety drinking capacity test. The intervention group comprised of 150 mg itopride. Patients in both arms were followed for 4 wk.

RESULTS

Mean age of the recruited participant 33 years (SD = 7.6) and most of the recruited individuals, i.e., 21 (67.7%) were males. We found that there was no effect of itopride on gastric accommodation as measured at different in volumes in the itopride and control group with the empty stomach (P = 0.14), at 20 min (P = 0.38), 30 min (P = 0.30), 40 min (P = 0.43), 50 min (P = 0.50), 60 min (P = 0.81), 90 min (P = 0.25) and 120 min (P = 0.67). Gastric emptying done on a sub sample (n = 11) showed no significant difference (P = 0.58) between itopride and placebo group. There was no significant improvement in the capacity to tolerate liquid in the itopride group as compared to placebo (P = 0.51). Similarly there was no significant improvement of symptoms as assessed through a composite symptom score (P = 0.74). The change in QT interval in itopride group was not significantly different from placebo (0.10).

CONCLUSION

Our study found no effect of itopride on gastric accommodation, gastric emptying and maximum tolerated volume in patients with FD.

Validation of the Leuven Postprandial Distress Scale, a questionnaire for symptom assessment in the functional dyspepsia/postprandial distress syndrome

BACKGROUND

A validated patient-reported outcome instrument is lacking for the functional dyspepsia/postprandial distress syndrome.

AIM

To validate the Leuven Postprandial Distress Scale (LPDS).

METHODS

The LPDS diary, comprising eight symptoms with verbal descriptors rated for severity (0-4), was derived from focus groups and cognitive debriefing. It was used in a 2-week run-in, 8-week double-blind placebo-controlled trial of itopride 100 mg t.d.s. Results in 60 patients, with concealed treatment allocation, were used to analyse LPDS content validity, consistency, reliability and responsiveness. Patients also filled out Patient Assessment of Gastrointestinal Symptoms (PAGI-SYM), Nepean Dyspepsia Index, overall treatment evaluation and overall symptom severity questionnaires. Construct validity was evaluated by known-group analyses and by correlating LPDS with these additional questionnaires. Minimum Clinically Important Difference was determined from threshold changes in anchor questionnaires.

RESULTS

Symptom patterns and factor analysis identified three cardinal symptoms of postprandial distress syndrome (early satiation, postprandial fullness, upper abdominal bloating), whose mean intensities generate weekly LPDS scores. Known-groups analysis showed large-effect-size differences in LPDS scores (Cohen's d = 2.16). Strong correlations (r > 0.57) between LPDS scores and relevant anchors at baseline indicate good convergent validity. Internal consistency of LPDS was good (α > 0.85) with high inter-item correlations (0.67-0.76), and test-retest reliability (r = 0.85). Changes in LPDS scores were highly convergent with changes in overall treatment evaluation, overall symptom severity and PAGI-SYM (r > 0.52). minimum clinically important difference analysis generated thresholds of 0.4-0.6.

CONCLUSIONS

The Leuven Postprandial Distress Scale, which is supported by the European Medicines Agency, is a sensitive and reliable patient-reported outcome instrument to assess symptoms in the functional dyspepsia/postprandial distress syndrome.

[Gastroparesis. Definition, diagnostics, and therapy]

Gastroparesis is characterized by a constellation of upper gastrointestinal symptoms in association with delayed gastric emptying in the absence of mechanical outlet obstruction from the stomach. Major symptoms are nausea, vomiting, early satiety or postprandial fullness, bloating, and abdominal or epigastric pain. Idiopathic, diabetic, and postsurgical causes represent the most common etiologies. Diagnostic procedures for the evaluation of gastroparesis comprise gastric emptying scintigraphy (gold standard), (13)C-octanoate breath testing, and a wireless motility capsule. Management of gastroparesis includes normalization of nutritional state, relief of symptoms, glycemic control, and improvement of gastric emptying. Medical treatment entails use of prokinetic drugs, which are currently the first-line therapy. Nausea and vomiting might be positively influenced by antiemetic drugs. Gastric electronic stimulation and surgical interventions should be used in well-defined patients and represent a therapeutic option in tertiary centers.

Functional dyspepsia and the Rome criteria: a success story

The Rome III criteria for functional dyspepsia (FD), published in 2006, immediately generated controversy but have arguably helped to jump start the field in terms of mechanistic and therapeutic research. One controversy has surrounded the veracity of FD symptom subgroups and their overlap. In clinical practice the overlap of postprandial distress syndrome (PDS) and epigastric pain syndrome (EPS) is striking. In this issue, results from Belgium suggest overlap can be reduced by reclassifying those who have postprandial pain or nausea as PDS, and meal-related symptoms predominate in FD. This is consistent with other objective experimental observations. The realization most FD occurs postmeal ingestion is driving a new conceptualization of the syndrome. For example, the observation there is an excess of duodenal eosinophils in PDS has been confirmed, with recent observations implicating increased duodenal permeability and immune activation. The link between PDS and anxiety, not identified in EPS, provides yet further evidence for distinct pathophysiological entities. While symptom-based criteria likely need refinement, the recognition of PDS and EPS has promoted exciting progress.

DA-9701: A New Multi-Acting Drug for the Treatment of Functional Dyspepsia

Motilitone^® (DA-9701) is a new herbal drug that was launched for the treatment of functional dyspepsia in December 2011 in Korea. The heterogeneous symptom pattern and multiple causes of functional dyspepsia have resulted in multiple drug target strategies for its treatment. DA-9701, a compound consisting of a combination of Corydalis Tuber and Pharbitidis Semen, has being developed for treatment of functional dyspepsia. It has multiple mechanisms of action such as fundus relaxation, visceral analgesia, and prokinetic effects. Furthermore, it was found to significantly enhance meal-induced gastric accommodation and increase gastric compliance in dogs. DA-9701 also showed an analgesic effect in rats with colorectal distension induced visceral hypersensitivity and an antinociceptive effect in beagle dogs with gastric distension-induced nociception. The pharmacological effects of DA-9701 also include conventional effects, such as enhanced gastric emptying and gastrointestinal transit. The safety profi le of DA-9701 is also preferable to that of other treatments.

Gastroparesis: a review of current and emerging treatment options

Gastroparesis is a motility disorder of the stomach causing delay in food emptying from the stomach without any evidence of mechanical obstruction. The majority of cases are idiopathic. Patients need to be diagnosed properly by formal testing, and the evaluation of the severity of the gastroparesis may assist in guiding therapy. Initially, dietary modifications are encouraged, which include frequent and small semisolid-based meals. Promotility medications, like erythromycin, and antiemetics, like prochlorperazine, are offered for symptom relief. 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, can be considered. Hemin therapy and gastric electric stimulation are emerging treatment options that are still at different stages of research. Regenerative medicine and stem cell-based therapies also hold promise for gastroparesis in the near future.

The effects of itopride on oesophageal motility and lower oesophageal sphincter function in man

BACKGROUND

Itopride is a new prokinetic agent that combines antidopaminergic and cholinesterase inhibitory actions. Previous studies suggested that itopride improves heartburn in functional dyspepsia, and decreases oesophageal acid exposure in gastro-oesophageal reflux disease. It remains unclear whether this effect is due to effects of itopride on the lower oesophageal sphincter (LES).

AIMS

To study the effects of itopride on fasting and postprandial LES function in healthy subjects.

METHODS

Twelve healthy volunteers (five men; 32.6 ± 2.0 years) underwent three oesophageal sleeve manometry studies after 3 days premedication with itopride 50 mg, itopride 100 mg or placebo t.d.s. Drug was administered after 30 min and a standardized meal was administered after 90 min, with measurements continuing to 120 min postprandially. Throughout the study, 10 wet swallows were administered at 30-min intervals, and gastrointestinal symptoms were scored on 100 mm visual analogue scales at 15-min intervals.

RESULTS

Lower oesophageal sphincter resting pressures, swallow-induced relaxations and the amplitude or duration of peristaltic contractions were not altered by both doses of itopride, at all time points. Itopride pre-treatment inhibited the meal-induced rise of transient LES relaxations (TLESRs).

CONCLUSIONS

Itopride inhibits TLESRs without significantly affecting oesophageal peristaltic function or LES pressure. These observations support further studies with itopride in gastro-oesophageal reflux disease.

A slow caloric satiety drinking test in patients with temporary and permanent gastric electrical stimulation

OBJECTIVES

Improvement of gastric accommodation has been proposed as a potential explanation for the positive effect of gastric electrical stimulation (GES) on nausea/vomiting. A drinking test has been suggested as a noninvasive measure of gastric accommodation capacity.

METHODS

Eight patients with therapy refractory nausea and vomiting and nonapproved diagnosis for GES (chronic intestinal pseudo-obstruction (CIP, n=1), functional dyspepsia (FD, n=3), postsurgical gastroparesis (PSGP, n=4) underwent temporary percutaneous GES for 10-14 days, randomized to stimulation ON or OFF, respectively. 19 patients [CIP (n=1), diabetic gastroparesis (n=5), FD (n=5), idiopathic gastroparesis (n=4), PSGP (n=4)] received permanent GES (Enterra, Medtronic) (follow-up at baseline, 6 and 12 months). At the end of each stimulation period a slow caloric satiety drinking test was performed (Nutridrink 1.5 kcal/ml, 15 ml/min).

RESULTS

Healthy volunteers had higher drinking capacity compared to patients at baseline (1630 + or - 496 kcal vs. 887 + or - 412; P<0.001) and less composite symptom score (128 + or - 51 vs. 235 + or - 83; P<0.001). With temporary percutaneous GES, there was no significant change in drinking capacity during stimulation ON versus OFF (746 + or - 383 vs. 734 + or - 427 kcal) and symptom severity at the drinking test was unchanged. For patients having permanent GES there was no significant difference at 6 months (876 + or - 277 kcal) versus baseline, and no difference between symptomatic responders and nonresponders in change in drinking capacity (P=0.7).

CONCLUSION

GES had no effect on proximal gastric function as evaluated by the slow caloric satiety drinking test. This seems to be the case for patients with approved as well as nonapproved indications for GES, and irrespective of the symptomatic response.

Association between clinical manifestations of complicated and uncomplicated peptic ulcer and visceral sensory dysfunction

BACKGROUND AND AIMS

Peptic ulcer disease (PUD) usually manifests as either dyspepsia or less commonly with complications such as bleeding. Patients with bleeding ulcers are often asymptomatic until the bleeding occurs. A lack of dyspeptic symptoms might be explained by impaired visceral sensory function. The aim of this study was to assess symptom profiles and compare visceral sensory thresholds in patients with bleeding peptic ulcer (BPU) and uncomplicated PUD.

METHODS

A total of 30 patients with BPU, 25 with uncomplicated PUD and 32 healthy controls (HC) without dyspeptic symptoms were recruited. In ulcer patients after at least 8 weeks of ulcer treatment and an 8-hr fast, visceral sensitivity was tested using a standardized nutrient challenge with an enteral feeding solution. Five key symptoms (fullness, abdominal pain, retrosternal/abdominal burning, nausea, and regurgitation) were assessed using visual analog scales (0-100).

RESULTS

Twenty-five of the 30 (83%, 95% confidence interval 65-94%) patients with BPU had no dyspeptic symptoms compared with none of the 25 uncomplicated PUD patients. Patients with BPU and HC had significantly lower symptom responses (BPU 127.6 +/- 24.6, HC 89.8 +/- 13.9) to the nutrient challenge than uncomplicated PUD patients (338.4 +/- 56.2, P < 0.0001). Patients with dyspeptic symptoms (30/55) had significantly higher symptom responses (327.3 +/- 47.8) than the 25/55 patients without symptoms (98.9 +/- 23.4, P < 0.0001).

CONCLUSION

Most patients with BPU present without dyspeptic symptoms. Even after healing of the ulcer, patients with uncomplicated PUD have a significantly augmented symptom response to a standardized nutrient challenge compared to patients with complicated ulcers and HC. Differences in the processing of upper gastrointestinal visceral afferents may play a major role in the clinical presentation (complicated vs uncomplicated) of PUD.

Gastroparesis: Current diagnostic challenges and management considerations

Gastroparesis refers to abnormal gastric motility characterized by delayed gastric emptying in the absence of mechanical obstruction. The most common etiologies include diabetes, post-surgical and idiopathic. The most common symptoms are nausea, vomiting and epigastric pain. Gastroparesis is estimated to affect 4% of the population and symptomatology may range from little effect on daily activity to severe disability and frequent hospitalizations. The gold standard of diagnosis is solid meal gastric scintigraphy. Treatment is multimodal and includes dietary modification, prokinetic and anti-emetic medications, and surgical interventions. New advances in drug therapy, and gastric electrical stimulation techniques have been introduced and might provide new hope to patients with refractory gastroparesis. In this comprehensive review, we discuss gastroparesis with emphasis on the latest developments; from the perspective of the practicing clinician.

Tegaserod treatment for dysmotility-like functional dyspepsia: results of two randomized, controlled trials

OBJECTIVES

Therapies for dysmotility-like functional dyspepsia (FD) are limited. We studied tegaserod, a selective serotonin type 4 receptor agonist, in patients with FD.

METHODS

Two identical multicenter, double-blind, randomized, placebo-controlled trials enrolled women >/=18 yr with recurring mid-upper abdominal discomfort characterized by postprandial fullness, early satiety, and/or bloating. Patients were randomized to tegaserod 6 mg b.i.d. or placebo. Two patient-reported primary variables were assessed: percentage of days with satisfactory symptom relief, and symptom severity using the composite average daily severity score (CADSS).

RESULTS

In total, 2,667 women were randomized with no differences between trials in terms of recruitment method, Helicobacter pylori status, heartburn, or medication use. Mean percentage of days with satisfactory symptom relief for tegaserod versus placebo in Trial 1: 32.2%versus 26.6% (95% CI of treatment difference 2.82, 9.27; P < 0.01), Trial 2: 31.9%versus 29.4% (95% CI of treatment difference -0.21, 6.53; P= 0.066). Mean CADSS in Trial 1: 3.14 versus 3.35 (95% CI of treatment difference -0.29, -0.10; P < 0.0001), Trial 2: 3.15 versus 3.23 (95% CI of treatment difference -0.18, 0.01; P= 0.094). Meta-analysis showed significant benefit for both end points: increase in days with satisfactory relief 4.6% (95% CI 2.29, 6.96); decrease in CADSS 0.14 (95% CI 0.21, 0.07). Treatment effect was greater in patients with severe baseline symptoms. Diarrhea requiring study discontinuation was more common with tegaserod than placebo (4.1%vs 0.3%).

CONCLUSIONS

Some improvement in dysmotility-like FD was observed with tegaserod treatment. The clinical implication of this improvement is uncertain.

The Rome III Classification of dyspepsia: will it help research?

A major change in the Rome III criteria relates to the condition previously called functional dyspepsia (FD). Rome I and Rome II defined FD as pain or discomfort centered in the upper abdomen without a definite structural or biochemical explanation. The condition was further sub-classified into ulcer-like or dysmotility-like dyspepsia. However, subsequent studies failed to show that single-symptoms are present in the vast majority of patients, and most symptoms failed to correlate with any physiological abnormalities. In Rome III, FD as a broad category was no longer considered useful in terms of research, but rather was defined by two new symptom entities, namely epigastric pain (epigastric pain syndrome) and meal-related symptoms (postprandial distress syndrome). We predict these changes will stimulate new research into the underlying pathophysiological disturbances, as well as impact the diagnosis and treatment of dyspepsia; the classification should advance the field, and we review the challenges ahead.

Effect of itopride on gastric emptying in longstanding diabetes mellitus

Delayed gastric emptying (GE) occurs in 30-50% of patients with longstanding type 1 or 2 diabetes, and represents a major cause of morbidity. Current therapeutic options are limited. We aimed at evaluating the effects of itopride on GE in patients with longstanding diabetes. Twenty-five patients (20 type 1, 5 type 2; 10 males, 15 females; mean age 45.2 +/- 2.7 years; body mass index 27.5 +/- 0.9 kg m(-2); duration of diabetes 20.2 +/- 2.4 years) were enrolled in a double-blind, placebo-controlled, randomized, crossover trial. Subjects received both itopride (200 mg) and placebo t.i.d. for 7 days, with a washout of 7-14 days. GE (scintigraphy), blood glucose (glucometer) and upper gastrointestinal (GI) symptoms (questionnaire) were measured following each treatment period. The test meal comprised 100 g ground beef (99mTc-sulphur colloid) and 150 mL of 10% dextrose [67Ga-ethylenediaminetetraacetic acid (EDTA)]. There was a slight trend for itopride to accelerate both solid (P = 0.09) and liquid (P = 0.09) GE. With itopride treatment, the emptying of both solids and liquids tended to be more accelerated, as the emptying with placebo was slower (solids: r = 0.39, P = 0.057; liquids: r = 0.44, P < 0.03). Twelve (48%) patients had delayed solid and/or liquid GE on placebo and in this group, itopride modestly accelerated liquid (P < 0.05), but not solid (P = 0.39), emptying. Itopride had no effect on mean blood glucose during the GE measurement (placebo: 9.8 +/- 0.6 mmol L(-1) vs itopride: 9.6 +/-0.6 mmol L(-1)), or GI symptoms (placebo: 1.4 +/- 0.4 vs itopride: 1.8 +/- 0.5). Itopride, in a dose of 200 mg t.i.d. for 7 days, tends to accelerate GE of liquids and solids in longstanding diabetes. The magnitude of this effect appears to be modest and possibly dependent on the rate of GE without itopride.

Advances in roles of prokinetic agents in the treatment of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is characterized by the reflux of gastric content into esophagus with or without histological changes. Pathogenesis of GERD is lower esophageal sphincter (LES) dysfunction, abnormal clearing capacity of refluxed materials, delayed gastric emptying and abnormal resistance of esophageal mucosa to gastric acid, but the primary upper gastrointestinal motility dysfunction is regarded as the most important factor in general. Therefore, prokinetic agents which can restore gastric motility with increasing of LES and esophageal motility have been developed and used frequently in the treatment of GERD. There are several prokinetic agents such as metoclopramide, domperidone, cisapride and mosapride that facilitate acetylcholine release from the enteric cholinergic neurons through a selective 5-HT₄ receptor agonistic action. It is considered that prokinetic agents have the same effect as H2 blocker in the treatment of patients with mild GERD. Additionally, it was reported that a combination therapy with prokinetic agents and proton pump inhibitors (PPI) or H2 receptor antagonists (H2RAs) is more effective than monotherapy in patients with severe GERD. This article reviews the recent advances in the role of prokinetic agents in the treatment of gastroesophageal reflux disease.

The effect of short-term, low-dose tricyclic and tetracyclic antidepressant treatment on satiation, postnutrient load gastrointestinal symptoms and gastric emptying: a double-blind, randomized, placebo-controlled trial

Antidepressants are commonly prescribed for patients with functional dyspepsia. However, the effect of tricyclic antidepressants on satiation and gastric emptying remains unclear, and there are no data for tetracyclic compounds. To compare the effects of nortriptyline (maximum dose: 50 mg daily) and mirtazapine (30 mg daily) vs placebo on gastric emptying, gastric satiation and postprandial symptoms after a nutrient load in healthy volunteers. Randomized, double-blind, placebo-controlled study evaluated gastric function before and after 14 days of nortriptyline (n = 13), mirtazapine (n = 13), or placebo (n = 14) in healthy volunteers. Validated methods were used to study gastric emptying ((13)C-octanoate) and satiation postnutrient drink test. The three arms were comparable with regard to age, gender, body mass index and hospital anxiety/depression scale. There were no statistically significant effects of mirtazapine or nortriptyline on gastric emptying compared to placebo (P = 0.34). Maximum tolerated volume was similar on drug and placebo (P = 0.56). Aggregate symptom score 30 min postmaximum tolerated volume after nutrient drink challenge on placebo was 132 (+/-21), vs 165 (+/-21) on mirtazapine, and 126 (+/-21) on nortriptyline 50 mg respectively (P = 0.28). Tricyclic and tetracyclic antidepressant agents do not appear to have significant effects on gastric motor or satiation postnutrient challenge in healthy individuals at the doses tested.

Gastric motility

PURPOSE OF REVIEW

This review focuses on progress made in the field of gastric motility in the past year, emphasizing advances in understanding the motor physiology of the stomach in health and disease; noninvasive imaging technology and data on novel pharmacotherapeutics and other therapeutic interventions for gastroparesis.

RECENT FINDINGS

The differential conduction pattern in the interstitial cell of Cajal is responsible for the generation of the full spatio-temporal pattern of gastric peristalsis. The mitochondrial powerhouse provides the driving potential for the gastric slow waves. Females are more dependent on the nitrenergic system for gastric relaxation, which is predominantly affected in diabetes. The noninvasive modalities to evaluate gastric function have undergone substantial evolution in the past year. On the therapeutic front, a new generation of medications has been tested and holds promise for the near future. Gastric electrical stimulation is a viable option for medically refractory gastroparesis.

SUMMARY

Using dynamic imaging modalities, the pathophysiology of dyspepsia is becoming better understood and recognized as an end point of multifactorial dysfunction of the enteric neural circuitry. Mechanism-targeted drugs, stem cell transplantation and electrical stimulation options are becoming available.

Functional Dyspepsia: A New Rome III Paradigm

Functional dyspepsia (FD) is a condition commonly seen in gastroenterological practice. With the introduction of Rome III criteria in 2006, a new approach for categorizing patients has been recommended. The diagnostic criteria suggest that meal-related and pain-predominant symptom groupings that presumably have distinct pathophysiologic mechanisms and potentially different therapeutic targets exist. The new classification is in the early stages of testing; in the meantime, the umbrella term of FD should continue to be utilized in clinical practice. Treatment of FD remains a major challenge. Unfortunately, most of the agents used in practice have limited or no evidence of efficacy, and the results typically are short-lived once therapy is ceased. Appropriate therapy currently is based on a consideration of putative pathophysiologic mechanisms. Testing for and eradicating Helicobacter pylori is a first-line strategy irrespective of the symptom pattern. In patients who have epigastric pain, antisecretory agents are recommended. Antacids, bismuth, and sucralfate seem to be no better than placebo. For meal-related symptoms such as postprandial fullness or early satiety, prokinetics may confer some benefit. However, few choices are available, and the efficacy for those drugs on the market is limited at best. Antidepressants are of uncertain efficacy but are widely used. Psychological therapies seem promising and may confer benefits on both pain and meal-related symptoms. Efficacy of complementary medicines has been suggested in controlled trials, but more data are needed. Emerging treatments include gastric fundus relaxors and visceral analgesics, although their application in FD is still in the preliminary stages.

Severe gastroparesis: new treatment alternatives

Dopamine antagonists, such as metoclopramide and domperidone, and the motilin receptor agonist erythromycin have been the cornerstones in drug treatment of severe gastroparesis for more than a decade. No new drugs have been approved for treatment of this disorder in this period. Instead, the 5-HT4 agonist cisapride has been withdrawn due to side-effects. The effectiveness of intrapyloric botulinum toxin for gastroparesis remains to be shown. In the last decade, gastric electrical stimulation (GES) with a fully implantable device has evolved as a promising treatment, with significant effects on nausea and vomiting in most patients with severe, drug-refractory diabetic gastroparesis and postsurgical gastroparesis. A proportion of patients with severe idiopathic gastroparesis and patients with idiopathic nausea and vomiting also respond. More research is needed to achieve precise selection of responders/non-responders to GES, and to study the potential benefit of GES in other patient groups suffering from severe nausea or vomiting.