Effects of ranitidine and cisapride on acid reflux and oesophageal motility in patients with reflux oesophagitis: a 24 hour ambulatory combined pH and manometry study

Acid Suppressive Drugs

Histamine H₂ receptor antagonists (H₂RAs) suppress gastric acid production by blocking H₂ receptors in parietal cells. Studies have shown that proton pump inhibitors (PPIs) are superior to H₂RAs as a treatment for acid-related disorders, such as peptic ulcer disease (PUD) and gastroesophageal reflux disease (GERD). PPIs reduce gastric acid production by irreversibly inhibiting the H⁺/K⁺ ATPase pump, and they also increase gastric emptying. Although PPIs have differing pharmacokinetic properties, each PPI is effective in managing GERD and PUDs. However, PPIs have some limitations, including short plasma half-lives, breakthrough symptoms (especially at night), meal-associated dosing, and concerns associated with long-term PPI use. Potassium-competitive acid blockers (P-CABs) provide more rapid and profound suppression of intragastric acidity than PPIs. P-CABs are non-inferior to lansoprazole in healing erosive esophagitis and peptic ulcers, and may also be effective in improving symptoms in patients with non-erosive reflux disease. Acid suppressive drugs are the most commonly used drugs in clinical practice, and it is necessary to understand the pharmacological properties and adverse effects of each drug.

The Effect of H2 Receptor Antagonist in Acid Inhibition and Its Clinical Efficacy

The first histamine H₂ receptor antagonists (H₂RAs) were developed in the early 1970s. They played a dominant role in treating peptic ulcer disease and gastroesophageal reflux disease (GERD). H₂RAs block the production of acid by H⁺, K⁺-ATPase at the parietal cells and produce gastric luminal anacidity for varying periods. H₂RAs are highly selective, and they do not affect H1 receptors. Moreover, they are not anticholinergic agents. Sequential development of H₂RAs, proton pump inhibitors (PPIs), and discovery of Helicobacter pylori infection changed the paradigm of peptic ulcer disease with marked decrease of morbidity and mortality. PPIs are known to be the most effective drugs that are currently available for suppressing gastric acid secretion. Many studies have shown its superiority over H₂RAs as a treatment for acid-related disorders, such as peptic ulcer disease, GERD, and Zollinger-Ellison syndrome. However, other studies have reported that PPIs may not be able to render stomach achlorhydric and have identified a phenomenon of increasing gastric acidity at night in individuals receiving a PPI twice daily. These nocturnal acid breakthrough episodes can be eliminated with an addition of H₂RAs at night. The effectiveness of nighttime dose of H₂RA suggests a major role of histamine in nocturnal acid secretion. H₂RAs reduce secretion of gastric acid, and each H₂RA also has specific effects. For instance, nizitidine alleviates not only symptoms of GERD, but also provokes gastric emptying, resulting in clinical symptom improvement of functional dyspepsia. The aim of this paper was to review the characteristics and role of H₂RAs and assess the future strategy and treatment of upper gastrointestinal disease, including acid related disorders.

Regionally dependent neuromuscular functions of motilin and 5-HT₄ receptors in human isolated esophageal body and gastric fundus

BACKGROUND

Motilin agonists promote human gastric motility and cholinergic activity, but excitatory and inhibitory actions are reported in the esophagus. The effect of 5-HT₄ agonists in esophagus is also unclear. Perhaps the use of drugs with additional actions explains the variation. The aim, therefore, was to examine how motilin and prucalopride, selective motilin and 5-HT₄ receptor agonists, modulate neuromuscular functions in human esophagus and gastric fundus.

METHODS

Electrical field stimulation (EFS) evoked nerve-mediated contractions of circular and longitudinal muscle from human esophageal body and circular muscle from gastric fundus.

KEY RESULTS

In esophageal circular muscle EFS evoked brief contraction, followed by another contraction on termination of EFS, each prevented by atropine. Nitric oxide synthase inhibition facilitated contraction during EFS and the overall contraction became monophasic. In esophagus longitudinal muscle and gastric fundus, EFS evoked cholinergically mediated, monophasic contractions, attenuated by simultaneous nitrergic activation. Motilin (100-300 nM) reduced esophagus circular muscle contractions during EFS, unaffected by L-NAME or apamin. Motilin 300 nM also reduced EFS-evoked contractions of longitudinal muscle. Similar concentrations of motilin facilitated cholinergic activity in the fundus and increased baseline muscle tension. Prucalopride facilitated EFS-evoked contractions in esophagus (tested at 30 μM) and fundus (0.1-30 μM).

CONCLUSIONS & INFERENCES

Selective motilin and 5-HT₄ agonists have different, region-dependent abilities to modulate human esophageal and stomach neuromuscular activity, exemplified by weak inhibition (motilin) or excitation (5-HT₄) in esophageal body and excitation for both in stomach. In different patients with motility dysfunctions, motilin and 5-HT₄ agonists may reduce gastro-esophageal reflux in different ways.

Systematic review: cardiovascular safety profile of 5-HT(4) agonists developed for gastrointestinal disorders

BACKGROUND

The nonselective 5-HT(4) receptor agonists, cisapride and tegaserod have been associated with cardiovascular adverse events (AEs).

AIM

To perform a systematic review of the safety profile, particularly cardiovascular, of 5-HT(4) agonists developed for gastrointestinal disorders, and a nonsystematic summary of their pharmacology and clinical efficacy.

METHODS

Articles reporting data on cisapride, clebopride, prucalopride, mosapride, renzapride, tegaserod, TD-5108 (velusetrag) and ATI-7505 (naronapride) were identified through a systematic search of the Cochrane Library, Medline, Embase and Toxfile. Abstracts from UEGW 2006-2008 and DDW 2008-2010 were searched for these drug names, and pharmaceutical companies approached to provide unpublished data.

RESULTS

Retrieved articles on pharmacokinetics, human pharmacodynamics and clinical data with these 5-HT(4) agonists, are reviewed and summarised nonsystematically. Articles relating to cardiac safety and tolerability of these agents, including any relevant case reports, are reported systematically. Two nonselective 5-HT(4) agonists had reports of cardiovascular AEs: cisapride (QT prolongation) and tegaserod (ischaemia). Interactions with, respectively, the hERG cardiac potassium channel and 5-HT(1) receptor subtypes have been suggested to account for these effects. No cardiovascular safety concerns were reported for the newer, selective 5-HT(4) agonists prucalopride, velusetrag, naronapride, or for nonselective 5-HT(4) agonists with no hERG or 5-HT(1) affinity (renzapride, clebopride, mosapride).

CONCLUSIONS

5-HT(4) agonists for GI disorders differ in chemical structure and selectivity for 5-HT(4) receptors. Selectivity for 5-HT(4) over non-5-HT(4) receptors may influence the agent's safety and overall risk-benefit profile. Based on available evidence, highly selective 5-HT(4) agonists may offer improved safety to treat patients with impaired GI motility.

New pharmacologic approaches in gastroesophageal reflux disease

This article highlights current and emerging pharmacological treatments for gastroesophageal reflux disease (GERD), opportunities for improving medical treatment, the extent to which improvements may be achieved with current therapy, and where new therapies may be required. These issues are discussed in the context of current thinking on the pathogenesis of GERD and its various manifestations and on the pharmacologic basis of current treatments.

Cisapride: what can we learn from the rise and fall of a prokinetic?

Cisapride, the prototype serotonergic agent, evolved from a body of research that defined the key roles of serotonergic receptors in gastrointestinal motor and sensory function. Impressed by its in vitro properties and encouraged by clinical trial data, cisapride became the drug of choice for the treatment of a wide range of motility disorders and clinicians appeared impressed by its efficacy and comfortable with its side-effect profile. Once serious cardiac events began to be reported in association with cisapride therapy, dark clouds rapidly gathered and soon enveloped the drug, leading to its widespread withdrawal from markets. What lessons can we learn from the story of cisapride? How can its brief but spectacular rise and equally sensational demise inform the development of new drugs which are so sorely needed in the management of motility and functional gastrointestinal disorders? This review explores the background to the development of cisapride, its history in clinical trials and the experience with adverse events and, in so doing, attempts to identify lessons for the future in the therapeutics of enteric neuromodulatory drugs.

New pharmacologic approaches in gastroesophageal reflux disease

This article highlights current and emerging pharmacological treatments for gastroesophageal reflux disease (GERD), opportunities for improving medical treatment, the extent to which improvements may be achieved with current therapy, and where new therapies may be required. These issues are discussed in the context of current thinking on the pathogenesis of GERD and its various manifestations and on the pharmacologic basis of current treatments.

Comparative study of nizatidine and famotidine for maintenance therapy of erosive esophagitis

BACKGROUND

The therapeutic effect of combined administration of prokinetics and histamine H2 receptor antagonists (H2RA) in gastroesophageal reflux disease is reported to be superior to that of monotherapy with H2RA alone. In addition to its acid-suppressing effect, the H2RA nizatidine also has a prokinetic action by suppressing acetylcholine esterase. The present multicenter, randomized controlled study was performed to investigate whether nizatidine is superior to famotidine, which does not suppress acetylcholine esterase activity, in maintenance therapy for erosive esophagitis. In addition, the question as to whether the grade of erosive esophagitis affects the non-recurrence rate during the maintenance therapy with H2RA was also investigated.

METHODS

Seventy-two patients with endoscopically healed erosive esophagitis after 8 weeks of initial treatment with proton pump inhibitors were randomly divided into two groups. Patients in the nizatidine group were treated with 150 mg nizatidine twice a day (b.i.d.), while patients in the famotidine group were treated with 20 mg famotidine b.i.d. for 6 months. At the end of therapy, and at the time when patients complained of symptoms, endoscopic investigations were repeated to find out whether the esophagitis had recurred.

RESULTS

Nizatidine produced a significantly higher non-recurrence rate than famotidine (P = 0.049 in intention-to-treat [ITT] analysis). This difference of remission rate between nizatidine and famotidine was observed mainly in grade B esophagitis (P = 0.016 in ITT analysis).

CONCLUSION

Nizatidine is a more effective H2RA than famotidine in the maintenance therapy of patients with reflux esophagitis.

Nizatidine and cisapride increase salivary secretion in rats

Saliva is a neurally induced solution with buffering capacity against acidic solutions. Salivation therefore plays an important role in defending the esophageal mucosa against refluxed gastric acid and is evoked by cholinergic stimulation. Both nizatidine and cisapride are reported to increase acetylcholine concentrations in the postganglionic cholinergic synapses. We performed this study to clarify the effect of administration of nizatidine and cisapride on salivary secretion. Eight-week-old male Sprague-Dawley rats were used for the experiments. Histamine-stimulated gastric acid secretion was measured after intraduodenal administration of nizatidine or famotidine to determine the equipotent acid-suppressing doses. Salivary secretion was then measured for 3 hr after intraduodenal administration of nizatidine (30 mg/kg), famotidine (3 mg/kg), or cisapride (1 mg/kg). Both nizatidine and famotidine dose-dependently inhibited histamine-stimulated gastric acid secretion. Total salivary secretion was significantly increased by nizatidine (P = 0.02) and cisapride (P = 0.02) but not by famotidine (P = 0.50) compared with controls.

Effect of reflux and esophagitis on esophageal volume and acid clearance in piglets

BACKGROUND/AIMS

The study investigates esophageal motor function and esophageal clearance immediately after surgical induction of reflux in piglets and 8 weeks later after peptic esophagitis has developed.

METHODS

Twenty-four sedated, nonintubated piglets were divided into three groups: sham (laparotomy only), reflux (distal esophageal myotomy), and reflux + esophagitis (8 weeks after myotomy). All animals underwent stationary manometry of the esophagus with a four-lumen perfused assembly after injection of 1-, 2-, and 3-mL boluses of saline and acid into the proximal esophagus. Simultaneous pH monitoring allowed assessment of acid clearance. Wave features and clearance times after saline and acid were compared among groups.

RESULTS

There were minor changes in peristaltic activity of the esophagus after saline boluses in animals with reflux. Acid clearance time was prolonged, especially the time to re-establish resting esophageal pH, in animals with esophagitis. These changes, which were volume-dependent, were related to the loss of peristaltic organization of the esophageal waves. The esophageal wave frequency, amplitude, and duration were only slightly changed by the induction of reflux and by esophagitis.

CONCLUSIONS

The esophagus affected by acid reflux, with or without esophagitis, was capable of near-normal motor responses after boluses of saline. Reflux impaired the peristaltic response to acid, and the effect was more pronounced when reflux and esophagitis were both present. The acid clearance time was also strikingly prolonged in the presence of reflux and esophagitis. The results suggest that long episodes of reflux seen on pH tracings from individuals with esophagitis might be secondary both to acid-related motor dysfunction and large volumes of refluxate.

The effect of mosapride on oesophageal motor function and acid reflux in patients with gastro-oesophageal reflux disease

OBJECTIVE

To evaluate the efficiency of the 5-HT4 agonist and 5-HT3 antagonist mosapride, as compared with cisapride, on oesophageal acid reflux variables and oesophageal motor function in patients with chronic gastro-oesophageal reflux disease (GORD).

METHOD

Forty-one patients with proven GORD were included in a double-blind, randomised, double-dummy, three-way crossover study. All patients received mosapride 60 mg twice daily, mosapride 30 mg three times daily, and cisapride 20 mg twice daily for seven days in a randomised order, separated by a washout period of at least five days. Twenty-three patients underwent four combined ambulatory 24-h motility and pH recordings within two weeks before the start of treatment and on day seven of each treatment period. The remaining 18 patients underwent three ambulatory 24-h pH recordings only, i.e. on treatment day seven of each treatment period.

RESULTS

Mosapride had no significant effect on the total number of contractions in the oesophagus, or on the effectiveness, or possible effectiveness, of the propagations. Significant but numerically small effects on peristaltic durations and amplitudes were noted during both mosapride and cisapride treatment as compared with baseline values. The effect on acid reflux for both mosapride and cisapride was most pronounced for the duration of the longest reflux episode. The fraction of time with pH less than 4 was reduced by mosapride 30 mg three times daily in the supine position and by cisapride both totally and in the supine position. The number of reflux episodes was reduced significantly only by cisapride. Oesophageal clearance was reduced significantly by cisapride only in the supine position.

CONCLUSION

Mosapride had small but statistically significant effects, comparable to those of cisapride, on acid reflux variables and oesophageal motor function in patients with GORD.

Does the addition of a prokinetic to proton pump inhibitor therapy help reduce duodenogastro-oesophageal reflux in patients with Barrett's oesophagus?

OBJECTIVE

The metaplastic change of Barrett's oesophagus is linked to both acid and duodenal reflux together with impaired motility. Proton pump inhibitors (PPI) reduce acid reflux, but no treatment is available that reduces duodenogastro-oesophageal reflux (DGOR). The aim of this study was to investigate whether adding a prokinetic to PPI treatment could improve oesophageal motility and subsequently reduce reflux.

METHODS

Two groups of patients with Barrett's oesophagus on PPI therapy (prokinetic, n = 12; placebo, n = 11) were investigated. At visit 1, ambulatory oesophageal manometry was performed, and peristaltic and simultaneous wave percentage and characteristics were measured. DGOR and pH measurements were also performed. After treatment with either the prokinetic cisapride or placebo, all investigations were repeated (visit 2). Analysis of covariance and Spearman's correlation coefficients of changes from visit 1 to visit 2 were used to compare data.

RESULTS

There was no significant difference between the two groups with respect to DGOR, DGOR characteristics, or the percentage of peristalsis and simultaneous waves and their characteristics. There was no correlation between DGOR and motility changes. Although no significant differences existed between acid reflux in the two groups, five patients with high supine acid reflux showed a significant reduction after treatment with cisapride.

CONCLUSIONS

Addition of cisapride to PPI treatment does not appear to improve oesophageal motility or reduce DGOR in patients with Barrett's oesophagus.

A rational approach to uninvestigated dyspepsia in primary care: review of the literature

In this paper the rationale and limitations of the four most important approach strategies to dyspepsia in primary care (empiric treatment, prompt endoscopy, "test-and-scope", and "test-and-treat") are analysed. It is concluded that in the absence of alarm symptoms, a "test-and-treat" approach is currently the most rational approach provided that three conditions are met: (1) a highly accurate test should be used, (2) the prevalence of Helicobacter pylori in the population should not be too low, and (3) an effective anti-H pylori regimen should be prescribed taking sufficient time to instruct and motivate the patient.

Cisapride inhibits meal-stimulated gastric acid secretion and post-prandial gastric acidity in subjects with gastro-oesophageal reflux disease

BACKGROUND AND AIMS

KCNQ1 potassium channels in human gastric parietal cells are thought to be involved in gastric acid secretion. As cisapride can inhibit similar channels in other tissues and is an effective treatment for nocturnal heartburn, we examined the effects of cisapride on gastric and oesophageal acidity, gastric emptying and heartburn severity in subjects with gastro-oesophageal reflux disease.

METHODS

Subjects (n = 11) had suffered from heartburn four times or more per week for at least 6 months. Gastric pH and oesophageal pH were measured before, during and after a standard meal ingested over 15 min. Each subject received placebo or 10 mg cisapride orally, 30 min before the beginning of the meal. Meal-stimulated gastric acid secretion was calculated from the amount of HCl required to titrate the homogenized standard meal to pH 2 in vitro and the time required for the pH of the ingested meal to decrease to pH 2 in vivo. Heartburn severity was assessed at 15-min intervals beginning at the end of the meal. Gastric emptying of solids was measured using a [(13)C]-octanoic acid breath test.

RESULTS

Cisapride significantly decreased meal-stimulated gastric acid secretion by 20%, decreased integrated gastric and oesophageal acidity by 50-60% and transiently increased the expiration of (13)CO(2). Cisapride did not significantly alter heartburn severity.

CONCLUSIONS

The cisapride-induced decreases in meal-stimulated gastric acid secretion, gastric acidity and oesophageal acidity in subjects with gastro-oesophageal reflux disease can account for its beneficial clinical effects. These results also raise the possibility that gastric KCNQ1 potassium channels are important in meal-stimulated gastric acid secretion and possibly in the pathophysiology of gastro-oesophageal reflux disease.

Effects of ABT-229, a motilin agonist, on acid reflux, oesophageal motility and gastric emptying in patients with gastro-oesophageal reflux disease

AIM

The effect of ABT-229, a new macrolide with no antibacterial activity, on gastro-oesophageal reflux, oesophageal motility and gastric emptying in patients with gastro-oesophageal reflux disease was investigated.

METHODS

Twenty-one patients were treated with a placebo and ABT-229 (2.5, 5 or 10 mg b.d.) in a randomized, incomplete crossover study design. Ambulatory 24-h pH manometry was performed and gastric emptying was assessed by the 13C-octanoic acid breath test on the seventh day of treatment.

RESULTS

A significant decrease was found in the mean (+/- s.e.) percentage of reflux time (intra-oesophageal pH < 4) for ABT-229 5 mg b.d. and 10 mg b.d., but not for 2.5 mg b.d., compared with placebo. For ABT-229 5 mg, it was 8.5 +/- 0.5% vs. 10.7 +/- 0.7% (P < 0.038) and, for ABT-229 10 mg, it was 6.6 +/- 0.5% vs. 8.4 +/- 0.5% (P < 0.019). There were no significant differences in any of the analysed manometric parameters. In addition, the gastric half-emptying time for all doses of ABT-229 did not differ significantly from that after placebo.

CONCLUSIONS

ABT-229 is able to reduce slightly, but significantly, acid reflux in patients with gastro-oesophageal reflux disease. This effect does not appear to be due to a measurable improvement in oesophageal motility or gastric emptying.

Effect of aggressive therapy on laryngeal symptoms and voice characteristics in patients with gastroesophageal reflux

Gastroesophageal reflux (GER) is associated with a variety of laryngopharyngeal signs and symptoms. Injury of the laryngopharynx as a result of GER can be refractory to conventional antireflux therapy. This prospective study was undertaken to evaluate the prevalence of laryngopharyngeal signs and symptoms in patients with documented GER and to assess the response to a high-dose combination antireflux therapy consisting of cisapride and pantoprazole. Twenty-two patients with symptoms of GER were enrolled. After baseline evaluation using a history questionnaire for symptoms, laryngeal endoscopy and vocal acoustic analysis, patients were started on treatment consisting of pantoprazole 40 mg b.d. and cisapride 20 mg twice daily. Repeat history and otolaryngologic evaluation was performed at 4 weeks. Laryngopharyngeal symptoms were frequent in most patients, with throat clearing and globus being the most prevalent symptoms followed by vocal fatigue and excess mucus production. Almost 90% of the patients had abnormal endoscopic laryngeal findings but the acoustic parameters did not show any abnormal results except for mild elevation in the shimmer. After treatment, all symptoms and endoscopic abnormalities improved significantly except for intermittent dysphonia and laryngeal mucosal redness. Acoustic abnormalities did not change significantly following therapy. Laryngeal symptoms and voice abnormalities are highly prevalent in patients with GER. Combination antireflux therapy with a proton pump inhibitor and a prokinetic agent results in rapid symptomatic and endoscopic response in the majority of patients.

Influence of pantoprazole on oesophageal motility, and bile and acid reflux in patients with oesophagitis

BACKGROUND

Reflux of duodeno-gastric juice into the oesophagus appears to be involved in the pathogenesis of both reflux oesophagitis and oesophageal adenocarcinoma. Although proton pump inhibitors have been shown to decrease acid reflux and heal oesophagitis, their effect on biliary reflux and motility is less clear.

AIM

To investigate whether pantoprazole also reduces bile reflux and whether this is paralleled by a change in oesophageal motility.

METHODS

Combined 24-h measurements of intraoesophageal bilirubin concentration, pH and pressure were performed in 18 symptomatic patients with endoscopically proven reflux oesophagitis before and on day 28 of treatment with pantoprazole, 40 mg/day, under standardized conditions. A reflux symptom score was determined initially and every 2 weeks thereafter. After 56 days on medication, a control endoscopy was performed.

RESULTS

The symptom score and the acid and bile reflux improved significantly, whereas the motility parameters did not change during the study period. Helicobacter pylori-positive patients had a significantly higher bile reflux time (32.1 +/- 4.3%) than H. pylori-negative patients (16.3 +/- 3.1%) (P=0.009). The endoscopic healing rate was 89%. The cough symptoms disappeared in three of four patients.

CONCLUSIONS

The proton pump inhibitor pantoprazole decreases both acid and bile reflux. The decrease of bile reflux cannot be explained by increased oesophageal clearance as oesophageal motility did not improve with therapy. Interestingly, H. pylori infection of the stomach was associated with higher levels of oesophageal bile reflux.

Esophageal motor dysfunction persists in children after surgical cure of reflux: an ambulatory manometric study

BACKGROUND/PURPOSE

Esophageal dysmotility shown by perfusion manometry in children with gastroesophageal reflux can be primary or acquired. This study examines by combined ambulatory pH-metry and manometry the nature of motor dysfunction and whether it improves after surgical cure of reflux.

METHODS

Sixteen refluxing children aged 131 +/- 54 months were studied by combined ambulatory pH-metry and manometry before and more than 6 months after successful fundoplication. pH-metric and manometric variables were compared at both time end-points by paired statistical tests accepting a significance level of P less than.05.

RESULTS

Operation cured all patients clinically and pH-metrically, but, in spite of this, only the frequency of motor sequences decreased significantly after the operation from 1 (0.45) to 0.8 (0.6) waves per minute (median [interquartile range]). Wave amplitude and duration were similar in both conditions; the proportion of peristaltic waves was normal and did not change before and after the operation (79.5% [17.25] v 81.4% [21.5]; not significant), whereas the proportions of complete (63.2% [17.5] v 67.8% [19.3]; not significant) and effective (32.4% [31.95] v 27.25% [22.5]; not significant) waves were definitely low and remained so after treatment.

CONCLUSIONS

The esophagus of children with GER has mild disturbances of peristaltic activity with waves often incomplete, weak, and scarcely effective. Dismotility does not improve after successful fundoplication suggesting that it could be a primary phenomenon.

The efficacy of a 40-mg extended-release formulation of cisapride in the treatment of patients with gastro-oesophageal reflux

BACKGROUND

This study was conducted to assess the efficacy of a novel 40-mg extended-release formulation of cisapride in reducing gastro-oesophageal reflux.

METHODS

According to a double-blind, randomized, placebo-controlled design, 19 patients with pathological gastro-oesophageal reflux were treated with extended (40 mg o.d.) or immediate (10 mg q.d.s.) release formulations for two periods of 4 days each (pH-monitoring on day four). Patients received identical treatments in both periods to allow limits of agreement defining equivalent potency of both formulations to be derived from intra-individual variability of treatment effects.

RESULTS

The extended-release formulation decreased total and upright reflux times by 5.5 +/- 1.3% and 8.1 +/- 2.1% (P < 0.001), respectively. It did not change the percentage supine reflux time but diminished the mean duration of reflux episodes by 1.0 +/- 0.4 min (P=0.005). The total number of reflux episodes remained unaltered with both formulations. Immediately-released cisapride decreased total, upright, and supine acid exposures by 5.8 +/- 1.3%, 6.8 +/- 1.6% (P < 0.002) and 3.6 +/- 1.8%, respectively, and mean duration of episodes by 0.9 +/- 0.2 min (P </= 0.05). Equivalent potency for both formulations was accepted in terms of percentage total and upright acid exposure and mean duration of episodes.

CONCLUSIONS

The 40-mg extended-release formulation of cisapride decreases total acid exposure and in this study is equivalent to the conventional immediate-release 10 mg q.d.s. regimen. Cisapride primarily interferes with reflux by improving oesophageal acid clearance.

Prokinetic activity of nizatidine: implications for the management of patients with gastroesophageal reflux disease

Gastroesophageal reflux is a common condition caused mainly by motility disorders of the upper gastrointestinal tract. The most effective therapy combines acid suppression with a promotility agent. Nizatidine is a well-tolerated and effective histamine-2 (H2)-receptor antagonist used to suppress gastric acid secretion. Animal and human studies have conclusively demonstrated that nizatidine also has prokinetic activity comparable to that of cisapride, and its effect is evident <1 hour after administration of doses commonly used in clinical practice. This prokinetic activity occurs through noncompetitive inhibition of acetylcholine; this inhibition approximates the inhibition caused by neostigmine. Nizatidine appears to possess a prokinetic mechanism that may be helpful in treating patients with gastroesophageal reflux.

Five-year audit of ambulatory 24-hour esophageal pH-manometry in clinical practice

BACKGROUND

Esophageal function testing was developed to aid diagnosis in patients with negative endoscopy. Although combined 24-h esophageal pH-manometry is now commercially available, its routine clinical effectiveness has not yet been studied.

METHODS

From 1992 to 1996 we evaluated 303 consecutive patients who were first-time referrals to our unit for 24-h esophageal pH-manometry. The referral indications were gastroesophageal reflux disease, 47.2%; dysphagia, 18.5%; non-cardiac chest pain, 14.9%; connective tissue disease, 13.2%; and symptomatic patients after antireflux surgery, 6.3%.

RESULTS

Overall, esophageal function testing altered the diagnosis of 44% of the patients, confirmed it in 38%, and specifically changed the management of 66%. The final clinical 'diagnosis' was reflux disease, 54% (32% with non-specific esophageal motility disorder); connective tissue disease, 9.9%; achalasia, 9.6%; other specific esophageal motility disorders, 3.3%; non-specific esophageal motility disorders, 6.9%; and normal, 16.2%. The cost per testing was estimated to be US$305 and per change in management US$465.

CONCLUSION

Combined 24-h pH-manometry has been shown to be a useful and cost-effective test for the management of selected patients in whom the primary investigation was insufficient.

The effect of cisapride on duodenal acid exposure in the proximal duodenum in healthy subjects

AIM

To investigate the effect of the prokinetic drug, cisapride, on fasting and postprandial acid exposure in the proximal duodenum.

METHODS

Using a double-blind, placebo-controlled crossover study design, 12 healthy male volunteers were studied. After 1 week of dosing (cisapride 20 mg b.d. orally or placebo), fasting and postprandial antroduodenal pH-and pressure-recordings were made. Using a small-caliber (4 mm) catheter, containing one antral and two duodenal pH electrodes, and two antral and three duodenal pressure recording sites. Transmucosal potential difference was measured to ensure proper catheter position. Infusions of 0.1 N HCl were given in the duodenal bulb.

RESULTS

Endogenous acidification of the duodenal bulb occurred more frequently during phase II and postprandially, compared to phase I (P<0.001). During phase I, alkalinization of the antrum was observed. Cisapride significantly increased the postprandial number of duodenal acidic periods (P<0.02), but shortened their duration (P<0.04). The duodenal motor response elicited by exogenous acid was lower during phase I (P<0.05).

CONCLUSIONS

Antral and proximal duodenal acidity vary with the phases of the interdigestive motor complex. Cisapride shortens the individual periods of duodenal acidification.

Effect of cisapride on secondary peristalsis in patients with gastroesophageal reflux disease

OBJECTIVE

Improvement of esophageal acid clearance appears to be an important effect of cisapride in the treatment of reflux disease. The mechanism underlying this effect is not clear. Esophageal peristalsis is a major component of the acid clearance process. In normal subjects secondary peristalsis is an important mechanism of esophageal acid clearance during sleep, and this response appears to be impaired in patients with reflux esophagitis. The effects of cisapride on secondary peristalsis are not known. The aim of this study was to investigate the effects of cisapride on the triggering and characteristics of secondary peristalsis in patients with reflux esophagitis.

METHODS

In 17 patients with reflux esophagitis and impaired secondary peristalsis cisapride, 10 mg q.i.d., or placebo were administered in a randomized double blind, crossover design for 4 days separated by a 4-7 day washout period. On the fourth day of treatment, primary peristalsis and secondary peristalsis in response to 10- and 20-ml air boluses were assessed.

RESULTS

Secondary peristaltic success and amplitude were greater with the 20-ml bolus than with the 10-ml bolus. However, cisapride had no effect on either secondary peristaltic success or amplitude. Cisapride also had no effect on primary peristalsis or basal LES pressure.

CONCLUSIONS

The improvement in esophageal acid clearance by cisapride is not explainable by improvement in secondary peristalsis.

Effect of repeated injection and continuous infusion of omeprazole and ranitidine on intragastric pH over 72 hours

OBJECTIVE

In healthy subjects and patients with bleeding peptic ulcers, ranitidine and omeprazole, given parenterally, achieve high intragastric pH values on the first day of therapy. However, data on the antisecretory effect beyond the first 24 h is scanty. In addition, the superiority of either infusion or injection of omeprazole remains unproven. Thus, we have compared the antisecretory effect of high dose omeprazole and ranitidine infusion and injection over the critical first 72 h.

METHODS

A total of 34 healthy volunteers were randomized into a double-blind crossover 72 h intragastric pH-metry study (data compared: median pH, percentage of time with pH >4 and pH >6). Omeprazole-infusion: initial bolus of 80 mg + 8 mg/h; omeprazole-injection: initial bolus of 80 mg + 40 mg/6 h; Ranitidine-infusion: initial bolus of 50 mg + 0.25 mg/kg/h; ranitidine-injection: 100 mg/6 h.

RESULTS

Omeprazole-infusion versus ranitidine-infusion: on day 1: median pH 6.1 vs 5.1 (p = 0.01) and 95% vs 70% was pH >4 (p < 0.01); on day 2: median pH 6.2 vs 3.2 (p < 0.01); and 100% vs 38% was pH >4 (p < 0.01); on day 3: median pH 6.3 vs 2.7 (p < 0.01); 100% vs 26% was pH >4 (p < 0.01). Injections of both drugs were significantly less effective than the infusions on day 1. Thereafter, omeprazole injection was almost as effective as omeprazole infusion, whereas ranitidine injection and infusion were equally effective.

CONCLUSION

Our study shows, for the first time, that omeprazole infusion was significantly superior to all other regimens by having a high median pH >6 on each day. The tolerance effect of ranitidine, however, led to a rapid loss of antisecretory activity on days 2 and 3, rendering it inappropriate for situations in which high intragastric pH-levels appear to be essential.

The effect of healing oesophagitis on oesophageal motor function as determined by oesophageal scintigraphy and ambulatory oesophageal motility/pH monitoring

BACKGROUND

Oesophagitis has been shown by standard manometry to be associated with impaired oesophageal motility, but it remains unclear if this abnormality improves with healing of oesophagitis.

AIM

To determine if healing of oesophagitis improves oesophageal motility using solid bolus oesophageal transit scintigraphy and combined ambulatory oesophageal motility/pH monitoring.

METHODS

Patients with grade II-III oesophagitis underwent ambulatory motility/pH monitoring (using a Konigsberg catheter with four pressure transducers at 5 cm intervals) and solid bolus scintigraphy before and after treatment with omeprazole 20 mg b.d. for 8-14 weeks.

RESULTS

Three (11%) of the 28 patients failed to heal. Initial scintigraphy was abnormal in 18 (67%) of 27 patients (one refused scintigraphy). Twenty-three of the 25 healed patients had repeat studies showing no significant change in the number which were abnormal (16 (64%), P = 1.0) or the overall oesophageal transit time (P = 0.65). Due to intolerance of the technique, only 11 patients had ambulatory motility/pH performed both before and after healing, giving the study 90% power to detect a 5 mmHg increase in peristaltic amplitude. No significant improvement was seen in any motility or pH parameter after healing of oesophagitis.

CONCLUSION

Analysis of oesophageal motility showed no improvement in peristaltic activity after healing of oesophagitis, suggesting that the abnormal motility is either a primary disorder or an irreversible consequence of mucosal damage.

Esophageal function in achalasia: preoperative and postoperative manometric studies

BACKGROUND/PURPOSE

Aperistalsis observed in children with achalasia may be secondary to sphincteric spasm or reflect a primary esophageal dysfunction. The aim of this study was to assess manometrically sphincteric function and esophageal motility before and after successful myotomy.

METHODS

Conventional stationary and pull-through manometry were performed preoperatively in 14 patients and postoperatively in 13. Ambulatory 24-hour manometry was carried out in four and eight patients in these two groups, respectively, and the results were compared with those of 23 refluxing youngsters.

RESULTS

Sphincter hypertony with lack or incompleteness of relaxation was found preoperatively in all patients, and sphincter pressure decreased dramatically after myotomy in all of them. All patients had aperistalsis preoperatively, and only a few had some primary, but weak, contractions postoperatively. Ambulatory manometry results confirmed a reduced number of motor events even during meals and only insignificant improvement of progressiveness, completeness and amplitude of waves after myotomy irrespective of the time elapsed since the procedure, the degree of recovery of esophageal caliber, and the clinical outcome.

CONCLUSIONS

Motor disorders in achalasia in children are similar to those of adults with the same disease. Motor recovery is observed only in some patients, although it is never complete, and their esophagi will remain ineffective for life. Because myotomy destroys the sphincter, and motility is permanently impaired in this condition, a fundoplication must be interposed to allow long-term mucosal protection.

Treating the symptoms of gastro-oesophageal reflux disease: a double-blind comparison of omeprazole and cisapride

BACKGROUND

Few studies have specifically addressed the management of the symptoms of gastro-oesophageal reflux disease, and there are no comparative data in this respect for acid pump inhibitors and prokinetic agents.

METHODS

Following endoscopy 424 patients presenting with heartburn as the predominant symptom of gastro-oesophageal reflux disease were randomized to treatment with omeprazole 20 or 10 mg once daily, or cisapride 10 mg four times daily, in a double-blind, double-dummy, parallel group, multicentre study. Symptoms and quality of life were assessed at 4 weeks. Patients still experiencing heartburn continued therapy for a further 4 weeks and the assessments were repeated.

RESULTS

At 4 weeks, heartburn was resolved in 65% (95% CI: 57-73%), 56% (48-64%) and 41% (32%-49%) of patients treated, respectively, with omeprazole 20 mg and 10 mg once daily, and cisapride. Both omeprazole doses were significantly more effective than cisapride (P < 0.01). The same order of efficacy was observed regardless of the presence of erosive oesophagitis. Regurgitation and epigastric pain also improved to a greater degree with omeprazole than with cisapride. Quality of life was improved in all treatment groups, and the improvement in the reflux dimension of the Gastrointestinal Symptom Rating Scale (GSRS) score was significantly different between groups (P = 0.002).

CONCLUSIONS

Omeprazole 20 or 10 mg once daily is significantly more effective than cisapride in the resolution of heartburn, regardless of the presence of erosive oesophagitis, and this is accompanied by an improvement in patient quality of life.

Maintenance therapy with cisapride after healing of erosive oesophagitis: a double-blind placebo-controlled trial

BACKGROUND

There are few data on the role of prokinetic agents as maintenance therapy in moderately severe reflux oesophagitis despite the high relapse rate of this condition after healing.

AIMS

To determine whether cisapride is more effective than placebo as maintenance therapy after healing of moderate erosive oesophagitis in two respects: first, in preventing symptomatic relapse and preserving quality of life; and, second, in improving oesophageal motor function.

PATIENTS

Forty-two patients whose grade II-III oesophagitis had been healed with omeprazole were randomized to receive either cisapride 20 mg nocte or placebo for 6 months. Oesophageal pH monitoring and manometry were performed before starting maintenance therapy and after 4 weeks, and symptomatic status and quality of life were assessed at weeks 0, 4, 13 and 26.

RESULTS

After 4 weeks of maintenance therapy, lower oesophageal sphincter pressure improved in the cisapride group (16.4-21.9 mmHg, P = 0.01) but not in the placebo group (25.5-22.7 mmHg, P = 0.2). Oesophageal pH monitoring showed no significant changes in either group. Sixteen (76%) cisapride patients and 12 (57%) placebo patients withdrew within 4 weeks owing to symptomatic relapse (P = 0.2). After 26 weeks, 21 (100%) cisapride and 17 (81%) placebo patients had relapsed (log-rank analysis of survival time P = 0.07). Quality of life parameters deteriorated in both treatment groups to a similar degree.

CONCLUSION

Maintenance therapy with cisapride 20 mg nocte improves the lower oesophageal sphincter pressure in patients whose oesophagitis has been healed with omeprazole. However, cisapride is no better than placebo in preventing symptomatic relapse or deterioration in quality of life.

Gastroesophageal reflux disease. The long and the short of therapeutic options

Gastroesophageal reflux disease (GERD) is a common and treatable condition. Initial therapy includes lifestyle modifications, avoidance of certain medications, and use of antacids, alginic acid preparations, and over-the-counter histamine2 (H2) receptor antagonists. Escalation of therapy for acute disease relies primarily on H2 receptor antagonists given in conventional dosages. Although H2 receptor antagonists remain the cornerstone of therapy, sucralfate and promotility agents, especially cisapride, may offer alternatives. Most cases of GERD that are resistant to these therapies can be reliably healed with proton pump inhibitors (PPIs). Patients whose GERD is healed with one of the aforementioned agents often relapse unless they receive further therapy. For patients with mild disease, H2 receptor antagonists, cisapride, or a combination of the two may prevent recurrent symptoms. In severe disease, PPIs are the agents of first choice, but concerns about the safety of long-term use must be considered. In selected patients, surgery offers an option for long-term control of GERD. With present surgical techniques, symptom relief can be obtained with little risk of complications.

Pharmacokinetic optimisation in the treatment of gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GORD) is a very common disorder of upper gastro-intestinal motility, differing widely in severity and prognosis. Medical therapy of GORD has involved antacids, alginates, prokinetic agents and antisecretory compounds, primarily H2 receptor antagonists and proton pump inhibitors. Knowledge of the pharmacokinetics of these compounds is important, to optimise the therapeutic benefit in each patient. GORD patients are often elderly and pharmacokinetics are move variable in this group. Furthermore, they often suffer from other diseases needing medical therapy and may need a combination of drugs to heal reflux oesophagitis and relieve reflux symptoms. The ideal therapy for GORD will have linear pharmacokinetics, a relatively long plasma half-life (t1/2), a duration of action allowing once daily administration, and a stable effect independent of interactions with food, antacids and other drugs. Over-the-counter antacids and alginates are widely used, buy may affect absorption of H2 receptor antagonists like cimetidine and ranitidine. Aluminium-containing antacids may, over time, cause toxicity in patients with renal insufficiency. In the treatment of GORD, cisapride presents important advantages over earlier prokinetic compounds, with a longer plasma t1/2, low penetration of the blood-brain barrier and fewer adverse effects. The group of H2 receptor antagonists is still the most frequently use therapy for GORD. Linear pharmacokinetics make dose adjustments easy and safe. In individual patients, suppression of gastric secretion is related to the area under the plasma concentration-time curve (AUC), but there is wide interindividual variation in the effect of the same oral dose. Only with frequent administration and high doses will acid suppression approximate that of proton pump inhibitors. Tolerance, with loss of effect over time, however, is most pronounced in this situation. H2 receptor antagonists seem well suited for on-demand treatment of reflux symptoms, due to the rapid onset of effect and a decrease likelihood of the development of tolerance. Effervescent formulations provide more rapid absorption and almost immediate clinical effect. Cimetidine, however, causes interference with the metabolism of several other drugs in common use. In elderly patients elimination is delayed and in patients with renal insufficiency, dose reductions of all H2 receptor antagonists are recommended. The most effective medical therapy for any severity of GORD, particularly in severe oesophagitis, are the proton pump inhibitors. The substituted benzimidazoles (omeprazole, lansoprazole and pantoprazole), are prodrugs which once trapped and activated in the acid milieu of the gastric glands potently suppress gastric secretion of acid and pepsin. Their long duration of action, more related to the slow turnover of parietal cell H(+)-K+ ATPase molecules, allows once daily administration in most patients. Interindividual variation in bioavailability sometimes calls for higher doses or twice daily administration. Acid suppression is closely related to the AUC. Omeprazole is prone to interaction with the metabolism of other drugs, some of which may e be clinically important. Lansoprazole seems to have an earlier onset of action than omeprazole, ascribed to higher bioavailability during the first days of treatment. Proton pump inhibitors have a slow onset of action, which makes them unsuited for on-demand therapy. Clinical practice in GORD calls for the use of not one but several substances, according to the severity and symptom pattern of the patient. Pharmacokinetic optimisation in the treatment of GORD is a question of selecting the most suitable substances and administration schemes within each group. Cisapride is superior to other prokinetics in terms of longer plasma t1/2 and less toxicity. Amongst H2 receptor antagonists, the more long-acting compounds, ranitidine and famotidine, will improve acidity control througho

Cricoid pressure decreases lower oesophageal sphincter tone in anaesthetized pigs

PURPOSE

Previous studies have shown a decrease of lower oesophageal sphincter (LOS) tone during stimulation of the upper oesophageal sphincter. Therefore, we hypothesized that during anaesthesia, cricoid pressure could result in a decrease in LOS pressure.

METHODS

The LOS and oesophageal barrier pressures (BrP = LOSP minus gastric pressure) were obtained in 11 anaesthetized pigs with intraabdominal pressure of 15 mmHg using a manometric method (perfused catheters) before and during firm application of cricoid pressure. Reflux was assessed with concomitant recording of the lower oesophageal pH.

RESULTS

Cricoid pressure decreased LOSP from 31.0 +/- 14.5 mmHg to 26.1 +/- 12.7 mmHg (P < 0.001) leading to a 35% reduction of oesophageal barrier pressure (9 +/- 10.3 mmHg vs 13.7 +/- 12.4 mmHg; P < 0.001). No episodes of reflux were recorded.

CONCLUSIONS

This study shows that cricoid pressure decreases LOS tone in anaesthetized pigs. Although no gastrooesophageal reflux was recorded, this study suggests that, if cricoid pressure does not completely occlude the oesophagus, the decrease of oesophageal barrier pressure induced could favour the appearance of pulmonary aspiration.

Therapeutic strategies for motility disorders. Medications, nutrition, biofeedback, and hypnotherapy

Gastrointestinal motility is regulated by a complex balance of inhibitory and excitatory neuronal, humoral, and mechanical factors. The goal in the management of motility disorders is to maintain adequate nutrition while decreasing symptoms. This can be accomplished by medications and support of nutrition and biofeedback; the application of these therapeutic strategies to patients with gut motility disorders is reviewed.

Esophageal motility disorders and their coexistence with pathologic acid reflux in patients with noncardiac chest pain

BACKGROUND

The aim of this study was to determine which motility data of patients with noncardiac chest pain (NCCP) differ from those of controls on the basis of long-term manometry and to evaluate the coexistence of motility disorders and pathologic acid reflux. Further, motility disorders were tested as to whether they were secondary to acid reflux.

METHODS

Combined long-term pH/manometry was performed in 95 patients with NCCP, using one pH-electrode and two pressure transducers. The motility data were compared with those of healthy controls (n = 40). In addition, an intraindividual patient-oriented motility analysis was performed. Evaluated were the amplitude, the duration in the distal and proximal esophagus, and the type of propagation, propulsive and simultaneous, of esophageal contractions. Ten patients with pathologic acid reflux and hypermotility disorders received 20 mg omeprazole twice daily and were investigated again 4 weeks after therapy began.

RESULTS

The median distal pressure amplitude (39.4 versus 28.9 mmHg, p < 0.0001) and the median percentage of simultaneous contractions (18.5% versus 10%; p < 0.0001) were significantly higher in patients with NCCP than in controls. In addition, patients whose symptoms correlated with abnormal motility (n = 18) had a significantly higher median duration of contractions (3.8 sec versus 3.2 sec; p < 0.03) than controls Patients with pathologic acid reflux showed a higher median distal pressure amplitude (38.3 mmHg versus 28.9 mmHg; p < 0.0001) and median percentage of simultaneous contractions (18% versus 10%; p < 0.0001) than controls. Furthermore, a high rate of coexistence with hypermotility disorders was observed (64%). These disorders persisted after acid suppression therapy.

CONCLUSIONS

Patients with NCCP differ from controls in their esophageal motility. Simultaneous contractions of increased amplitude and duration are pathologic. The intraindividual patient-oriented motility analysis is an appropriate evaluation method. Hypermotility disorders occur often in patients with pathologic acid reflux, but apparently they are not dependent on it.

Ambulatory 24-hour manometric and pH metric evidence of permanent impairment of clearance capacity in patients with esophageal atresia

Dysphagia and gastroesophageal reflux (GER) probably caused by structural disorganization of the esophagus occur frequently after repair of tracheoesophageal fistula (TEF), and the extent to which they may improve beyond childhood is not known. The aim of the present study is to assess by combined ambulatory 24-hour manometry and pH-metry the esophageal peristaltic activity and acid clearing capacity in adolescents and adults who had been operated on for TEF at birth. Twenty-two patients, aged 17.1 +/- 4.5 years (mean +/- SD), were examined with combined three-channel manometry and two-channel pH-metry followed by endoscopy and biopsy. Although they considered themselves healthy, on careful interrogation, 16 (72%) were found to have dysphagia, 13 (59%) had heartburn, 10 (45%) had foreign body impaction, and 7 (31%) had chronic respiratory tract disease. GER was detected in 12 (54%) patients (5 with histological esophagitis), 10 of whom had a pattern of prolonged nocturnal episodes with very slow clearance. All patients had diminished contractile activity with low-amplitude and short-duration waves that decreased from 0.53 +/- 0.35 waves per minute to 0.28 +/- 0.2 waves per minute during sleep. Propulsive activity was uniformly disorganized, with peristaltic sequences being few (less than 50% overall) and incomplete (above 80%). Finally, the acid-clearing capacity was nil; the proportions of ineffective sequences were above 90% for all periods considered, including sleep and mealtimes. The motor behavior of nonrefluxing and refluxing patients was identical despite the differences in esophageal acid exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

The clinical use of cisapride in gastro-oesophageal reflux disease, with particular focus on the long-term treatment aspects

BACKGROUND

The healing of oesophagitis, both symptomatic and endoscopic, can be obtained with cisapride, the results being equivalent to what has been achieved with H2RAs. For many patients, however, GORD is a chronic relapsing disease.

RESULTS

At least 40-50% of patients relapse within a year of initial healing. Important predictors for relapse are the severity of symptoms, the degree of mucosal damage, and the time it takes for the initial lesions to heal. Another important predictor of relapse, as shown in the cisapride maintenance studies, is the need for PPIs, probably because the most recalcitrant patients were selected for this therapy.

CONCLUSIONS

Patients with mild or moderate disease should be treated with intermittent or prolonged therapy with cisapride or H2RAs. Patients with severe disease should be given prolonged or permanent therapy with a PPI or with cisapride in combination with either an H2RA or a PPI. For the latter group, antireflux surgery should also be considered, especially in younger patients who have a completely incompetent closing mechanism of the lower oesophageal sphincter.

Cisapride. An updated review of its pharmacology and therapeutic efficacy as a prokinetic agent in gastrointestinal motility disorders

Cisapride is an orally administered prokinetic agent which facilitates or restores motility throughout the length of the gastrointestinal tract. It is a substituted piperidinyl benzamide, chemically related to metoclopramide, but unlike metoclopramide, cisapride is largely devoid of central depressant or antidopaminergic effects. In placebo-controlled trials, cisapride improved healing rates and symptoms in both adults and children with reflux oesophagitis. Maintenance therapy with cisapride at half the healing dose is effective in reducing the incidence of relapse. Symptoms are also alleviated in patients with functional dyspepsia, and gastric emptying and symptoms are improved in most patients with gastroparesis, an effect which is sustained during long term administration. However, the efficacy of cisapride in end-stage gastroparesis remains less clear. Cisapride increases stool frequency in patients with chronic constipation, and limited data suggest that the drug may also be beneficial in treating chronic intestinal pseudo-obstruction and irritable bowel syndrome. Cisapride demonstrated efficacy comparable with or superior to that of metoclopramide, and was at least as effective as cimetidine and ranitidine in patients with reflux disease. In patients with functional dyspepsia, cisapride has shown at least equal efficacy to domperidone, metoclopramide and ranitidine, and superior efficacy to cimetidine in the small comparative trials conducted to date. Adverse effects in patients receiving cisapride are generally transient and mild, with abdominal cramping, borborygmi, diarrhoea or loose stools most frequently reported. Central nervous system adverse effects are rare. Thus, with its favourable tolerability profile and demonstrated efficacy in a variety of gastrointestinal motility disorders, the position of cisapride as a valuable agent in the management of patients with gastrointestinal motility disorders is strengthening. However, larger well-controlled comparative trials of the drug with other agents are necessary before the relative position of cisapride in therapy can be categorically defined.