Stimulation of gastroduodenal motor activity: Dopaminergic and cholinergic modulation

Oesophageal spasm, vomiting and hyoscine hydrobromide patch

We report the case of a 60-year-old woman with metastatic breast cancer whose intractable nausea and vomiting were effectively managed with a hyoscine hydrobromide (scopolamine) patch. Contrast swallow revealed oesophageal spasm to be the underlying cause. Symptom relief may be attributed to the antimuscarinic properties of the patch, allowing lower oesophageal sphincter relaxation. Following patch use she was able to enjoy small meals and fluids without symptoms. This is the first time this mechanism of action of scopolamine for alleviating nausea and vomiting has been described in the literature.

Treatment of nausea and vomiting in terminally ill cancer patients

Nausea and vomiting is a common and distressing symptom complex in patients with far-advanced cancer, affecting up to 60% of individuals at some stage of their illness. The current approach to the palliative care of patients with nausea and vomiting is based on identifying the cause, understanding its pathophysiology and knowing the pharmacology of the drugs available for its amelioration. The following six main syndromes are identified: gastric stasis, biochemical, raised intracranial pressure, vestibular, mechanical bowel obstruction and ileus. A careful history, focused physical examination and appropriate investigations are needed to elucidate the syndrome and its cause, so that therapy is rational. Drugs are the mainstay of treatment in terminal cancer, and the main classes of antiemetic agents are prokinetics, dopamine antagonists, antihistamines, anticholinergics and serotonin antagonists. Dexamethasone and octreotide are also used, especially in bowel obstruction. Non-drug measures are important in relieving the associated distress. Patients should be able to die comfortably, without tubes. Despite decades of practice affirming this approach, the evidence base is weak and well designed studies are urgently needed.

Effect of Anticholinergics (Atropine, Glycopyrrolate) and Prokinetics (Metoclopramide, Cisapride) on Gastric Motility in Beagles and Labrador Retrievers

The effect of atropine, glycopyrrolate, metoclopramide and cisapride on the antral motility was investigated in eight dogs (four Beagles and four Labradors) using passive telemetry. Both anticholinergics induced a pronounced and lasting reduction of the intensity and frequency of the contractions. A definite dose-related inhibition of the antral motility was seen in Beagles, similar for both active substances. Low doses of atropine (0.02 mg/kg BW i.m.) and glycopyrrolate (0.005 mg/kg BW i.m.) completely inhibited the gastric motility for at least 30 min, whereas higher doses (0.04 or 0.01 mg/kg BW) caused a cessation of activity for more than 3 h. In Labradors, the effects of both active substances were not so dose related and the effect of glycopyrrolate lasted at least 6 h, whereas the effect of atropine gradually decreased after 3 h. A distinct breed difference regarding the effect of the two prokinetics on the antral motility was also observed. In Beagles, the prokinetics, at a low dose (metoclopramide 0.3 mg/kg BW, cisapride 0.2 mg/kg BW), resulted in a significant increase in the amplitude integral. Higher doses (metoclopramide 0.6 mg/kg BW, cisapride 0.5 mg/kg BW) also increased the integrals of the pressure profiles, but significantly less than with the lower doses. In Labradors, both medications, mainly at higher doses, resulted in an increase of the contraction amplitudes. The low dose had no (cisapride) or only a transient effect (metoclopramide). The frequency of the antral contractions was not at all influenced by cisapride, and only in Beagles metoclopramide resulted in a dose-related increase. It is not clear if the different results in Labradors and Beagles are because of breed or body weight.

KDR-5169, a new gastrointestinal prokinetic agent, enhances gastric contractile and emptying activities in dogs and rats

KDR-5169, 4-amino-5-chloro-N-[1-(3-fluoro-4-methoxybenzyl)piperidin-4-yl]-2-(2-hydroxyethoxy)benzamide hydrochloride dihydrate, is a new prokinetic with a dual action, i.e., stimulation of the 5-HT4 receptor and antagonism of the dopamine D2 receptor. In this study, we determined in vitro activities of KDR-5169 towards both receptors and demonstrated the effect of the compound on gastrointestinal motor activity in conscious dogs and rats. In dogs, intravenous KDR-5169 stimulated upper gastrointestinal motility in the fasting state and also eliminated the depressive effect of 3,4-dihydroxyphenylalanine (L-DOPA) on this motility in the postprandial state. The effect of KDR-5169 on gastric emptying was further characterized by the use of three rat gastroparesis models (dopamine D2 receptor agonist (quinpirol)-, abdominal surgery-, or combined-situation-induced). Domperidone (a dopamine D2 receptor antagonist) was effective in the quinpirol-delay and combination-delay models, and cisapride and mosapride (5-HT4 receptor agonists) were effective in the surgery-delay model. Only KDR-5169 eliminated the delay of gastric emptying in all three models. In addition, KDR-5169 accelerated emptying to above the normal level in the combination-delay model. These results suggest that KDR-5169 would be effective in various types of gastric ileus caused by different mechanisms.

The use of Scopoderm in palliative care

The drug hyoscine has several indications for symptom control for patients with end-stage disease. The transdermal preparation, Scopoderm, is most widely used to control excess salivary secretions but it can also have a role in the management of terminal secretions and in the control of nausea.

Drugs coordinating and restoring gastrointestinal motility and their effect on selected hypodynamic gastrointestinal disorders in horses and cattle

Hypodynamic gastrointestinal disorders in horses and cattle that are thought to benefit from treatment with drugs restoring and coordinating gastrointestinal motility include postoperative ileus and large colon impaction in the horse and displacement of the abomasum and dilatation of the cecum in cattle. Important physiologic, pathophysiologic and pharmacologic mechanisms involved in the intrinsic control of gastrointestinal motility include cholinergic, adrenergic, dopaminergic, serotoninergic, and opioid-mediated pathways. Preliminary results suggest that cisapride, acting on 5-Hydroxytryptamine receptors, might be useful for treatment of idiopathic postoperative ileus and the alpha 2-adrenoceptor blocking agent yohimbine for endotoxic postoperative ileus. Naloxone, an opioid antagonist, and neostigmine, an acetylcholinesterase inhibitor, are thought to restore motility of the large colon in cases of large colon impaction in the horse. Bethanechol and neostigmine significantly increase myoelectric activity of the cecum and proximal loop of the ascending colon in healthy cows. Investigations of the effects of prokinetic drugs on displacement of the abomasum of cattle do not allow any conclusions because no results derived from controlled experimental disease models are available.

Efficacy of cisapride therapy in functional dyspepsia

AIM

To assess the efficacy of cisapride therapy in relieving symptoms of functional dyspepsia.

METHODS

After a 2-week placebo run-in period, 61 out of 74 patients were eligible to enter a 4-week double-blind treatment phase, consisting of treatment with cisapride (10 mg) or placebo tablets t.d.s. Gastric emptying was assessed scintigraphically at entry to the study. Patients were stratified before treatment into those with or without active chronic (Helicobacter pylori) gastritis. Patients were also classified retrospectively into those with 'reflux-like' dyspepsia (n = 29) and those with 'motility-like' dyspepsia (n = 32).

RESULTS

At the end of the active treatment phase, there was a similar significant (P < 0.001) reduction in total symptom score from baseline in both cisapride (8.9 +/- 0.5 to 5.8 +/- 0.6) and placebo (9.7 +/- 0.6 to 5.5 +/- 0.6) groups. Scores for heartburn and continual bloating were significantly reduced in the cisapride but not the placebo group; improvement was attributable to patients with normal, rather than delayed, rates of gastric emptying. For continual bloating, significant improvement also occurred in the cisapride subgroup without gastritis, but not in the subgroup with gastritis (mean symptom score reduction 0.48 +/- 0.18, P = 0.03). For global evaluation by the investigator and by the patient, the overall improvement rates were not statistically different between cisapride and placebo groups. In those with normal gastric emptying, however, there was a significant (P = 0.01) improvement in general well-being in the cisapride but not in the placebo group.

CONCLUSIONS

We were unable to show major differences in the short-term efficacy of cisapride and placebo in functional dyspepsia. There were indications, however, of beneficial effects of cisapride over placebo in those with 'reflux-like' dyspepsia, and in those without gastroparesis.

The hypotensive effect of cisapride in rat

1. Cisapride is a prokinetic agent believed to facilitate acetylcholine release from the myenteric plexus of the gut. The aim of the present study was to investigate the effect of cisapride on blood pressure and the effects of muscarinic receptor antagonists on the cisapride-induced blood pressure changes. 2. Cisapride was given i.v. alone or 10 min after muscarinic receptor antagonists. Cisapride given i.v. produced a significant decrease in blood pressure in a dose-related manner. Atropine, AF-DX 116 and 4-DAMP given 10 min before cisapride injection, partially inhibited the hypotensive response to cisapride. In pithed rat, the effect of cisapride on blood pressure remained unaltered. 3. This study indicates that the action of cisapride is not through central mechanisms and part of cisapride's effect is through the cholinergic system.

Cisapride versus metoclopramide in the treatment of functional dyspepsia. A double-blind comparative trial

The efficacy and tolerability of cisapride (5 mg three times daily) and metoclopramide (10 mg three times daily) were evaluated in a randomized double-blind trial in patients with functional dyspepsia. Sixty patients, equally distributed in the two groups, entered the trial. After 4 weeks of treatment there was a significant improvement of symptom severity versus base line (p < 0.001) in both groups. The percentage of responders (with no or only mild symptoms) was 87% in the cisapride group and 77% in the metoclopramide group (no statistically significant intergroup difference). At the follow-up visit 2 weeks after completion of the trial this response rate was significantly higher in the cisapride group (73%) than in the metoclopramide group (47%) (p < 0.05). Four of the patients receiving cisapride and 2 of the patients receiving metoclopramide reported adverse events. On assessment of extrapyrimidal symptoms, relevant clinical values were found in one patient receiving metoclopramide. Increased prolactin concentrations were observed in seven patients of the metoclopramide group versus only 1 of the cisapride group (p < 0.05). The present data indicate that during the 2 weeks after completion of treatment in patients with functional dyspepsia, cisapride may result in a better, more sustained overall response when compared with metoclopramide.

Efficacy of cisapride in functional dyspepsia resistant to domperidone or metoclopramide: a double-blind, placebo-controlled study

A double-blind, placebo-controlled trial was performed to determine the therapeutic efficacy of cisapride in patients with refractory functional dyspepsia. A total of 147 patients with functional dyspepsia characterized by prominent epigastric pain or discomfort were randomized to 2 weeks' treatment with metoclopramide or domperidone (both 30 mg/day); of these, 53 patients unresponsive to dopamine antagonist treatment were randomized to cisapride 30 mg/day or placebo for an additional 2 weeks. Metoclopramide and domperidone produced comparable alleviation of epigastric symptoms; global efficacy was good or excellent in 62% and 57% of patients, respectively. In refractory patients, cisapride tended to display greater efficacy than placebo against epigastric pain, particularly at night. Global assessments of efficacy significantly favored cisapride over placebo, with good or excellent ratings in 65% and 32% of patients, respectively. Cisapride was well tolerated. Thus, cisapride appears to be an effective agent in functional dyspepsia unresponsive to other gastrokinetic agents.

Cisapride in chronic dyspepsia: results of a double-blind, placebo-controlled trial

The efficacy and tolerability of cisapride in chronic dyspepsia was evaluated in a randomized, double-blind, placebo-controlled study. After 4 weeks' treatment with oral cisapride 10 mg three times daily (n = 14), bloating and epigastric discomfort were significantly reduced compared with placebo (n = 15; p < 0.05). Moreover, the global response to treatment was excellent or good in 71.4% of patients in the cisapride group versus 20.0% with placebo. No significant side effects were observed. It is concluded that cisapride is an effective and well-tolerated treatment for chronic dyspepsia.

Cisapride in the prophylaxis of equine post operative ileus

Cisapride and domperidone were both effective in restoring electrical and mechanical activity, coordination between gastric and small intestinal activity cycles and the stomach to anus transit time in three ponies in which post operative ileus was induced experimentally. Cisapride (0.1 mg/kg bodyweight intramuscularly) for three to eight doses prevented idiopathic post operative ileus in 22 clinical cases requiring colic surgery. The only side effects after cisapride were increased bowel sounds and slight, transient sounds of discomfort. No adverse side effects were seen in 16 cases following anastomosis or enterotomy. Cisapride appears safe and effective in the prophylaxis of equine post operative ileus.

Rationale for the development of a novel gastrointestinal prokinetic, cisapride

Several promotility drugs have been used to correct disorders caused by disturbed gastrointestinal motility. However these drugs have various drawbacks. Their effects on smooth muscle activity may be restricted to part of the digestive system, or may not be very efficient. On the other hand, their use is somewhat limited by side effects: drugs may not be specific for the motor functions of the gastrointestinal tract or not even for the gastrointestinal tract itself. The desirability of improving the promotility effects and eliminating the secondary effects of existing drugs constituted the rationale for developing cisapride. This aim was achieved by influencing--in a physiological way--the release of acetylcholine, the main neurotransmitter in the 'gut brain', the myenteric plexus.

Actions of the novel gastrointestinal prokinetic agent cisapride on equine bowel motility

The effect of cisapride was evaluated on the normal fasting bowel motility of four ponies with chronically implanted electromechanical transducers. Cisapride was infused over 60-min periods at 0.05 mg/kg (n = 4), 0.1 mg/kg (n = 5) and 0.25 mg/kg (n = 5). It produced marked and prolonged increases in electrical and mechanical activity at all sites examined. In the stomach there was increased total contraction activity with increased contraction amplitude and a slight reduction in rate. In the small intestine there was an increase in irregular (phase II) activity with an increase in number and amplitude of contractions and a decrease in the number of regular (phase III) activity fronts. There was a decrease in the number of phase III fronts that spread distally from the jejunum to the ileum. The phase II activity was coordinated temporally with prolonged activity in the stomach. Cisapride increased electrical and contractile activity in the left dorsal colon with increased contraction amplitude and an increase in electrical activity in the small colon. In the stomach and small intestine cisapride produced dose-dependent increases in activity but in the left dorsal and small colon the intermediate dose (0.1 mg/kg) produced the largest and most consistent responses. Side-effects observed were increased bowel sounds and frequency of defaecation, a slight increase in heart rate and transient signs of discomfort at the highest (0.25 mg/kg) dose rate.