Prokinetics and reflux: a promise unfulfilled

How I Approach Laryngopharyngoesophageal Reflux (LPR)

The purpose of this article is to review the cornerstone and most recent literature regarding laryngopharynoesophageal reflux (LPR) including epidemiological characteristics, pathophysiology, symptoms, diagnosis, and management. The role of pepsin in the pathophysiology of LPR is highlighted in addition to new diagnostic modalities and pharmacologic therapies that target pepsin.

Postprandial gastric antral contractions in patients with gastro-oesophageal reflux disease: a scintigraphic study

Disturbed gastric contractility has been found in manometric studies in patients with gastro-oesophageal reflux disease (GORD), but the pathophysiological role of this abnormality is unclear. We aimed at assessing postprandial gastric antral contractions and its relationships with gastric emptying and gastro-oesophageal reflux in GORD patients. Fasted GORD patients (n = 13) and healthy volunteers (n = 13) ingested a liquid meal labelled with 72 MBq of 99mTechnetium-phytate. Gastric images were acquired every 10 min for 2 h, for measuring gastric emptying half time. Dynamic antral scintigraphy (one frame per second), performed for 4 min at 30-min intervals, allowed estimation of both mean dominant frequency and amplitude of antral contractions. In GORD patients (n = 10), acidic reflux episodes occurring 2 h after the ingestion of the same test meal were determined by ambulatory 24-h oesophageal pH monitoring. Gastric emptying was similar in GORD patients and controls (median; range: 82 min; 58-126 vs 80 min; 44-122 min; P = 0.38). Frequency of antral contractions was also similar in both groups (3.1 cpm; 2.8-3.6 vs 3.2 cpm; 2.4-3.8 cpm; P = 0.15). In GORD patients, amplitude of antral contractions was significantly higher than in controls (32.7%; 17-44%vs 23.3%; 16-43%; P = 0.01), and correlated positively with gastric emptying time (R(s) = 0.58; P = 0.03) and inversely with the number of reflux episodes (R(s) = -0.68; P = 0.02). Increased amplitude of postprandial gastric antral contractions in GORD may comprise a compensatory mechanism against delayed gastric emptying and a defensive factor against acidic gastro-oesophageal reflux.

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.

A novel antireflux device based on magnets

BACKGROUND

The problem of eliminating gastroesophageal reflux (GER) with simple, effective and devoid of unpleasant side effects procedures is still unresolved. We tried to settle this problem with a magnetic device that should be applied to the distal end of the esophagus.

MATERIALS AND METHODS

Two plastoferrite magnets of 2 x 4 x 0.5cm(1) were applied, on the opposite sides of a flaccid polyethylene tube mimicking the physical characteristics of the terminal esophagus. The two magnets attracting themselves compressed the tube, creating an artificial high-pressure zone that divided the tube in two segments. Both segments of the tube were connected to pressure transducers and a polygraph and one of them was connected to a hydraulic pump. The pressure was progressively increased in this segment up to a value sufficient to detach the magnets with consequent flowing of the water in the other segment of the tube.

RESULTS

The progressive increase of the pressure in a segment of the tube detached the magnets allowing a free flow into the other segment when the pressure reached an average value of 9.75+/-1.05 mmHg (mean+/-SD).

CONCLUSIONS

A couple of magnets clamping a tube with the characteristics of the distal esophagus is able to prevent the passage of liquid with a pressure value near to that of a normal lower esophageal sphincter. This magnetic device could be useful to maintain closed a sphincter unable to prevent gastroesophageal reflux.

Safety of potent gastric acid inhibition

The proton pump inhibitors are a very effective drug group for the control of gastric acid secretion, which makes them of great use in the medical practice setting, while at the same time they represent one of the treatment groups widely used in Western European countries. These factors lead to this drug group being prescribed in all age populations, quite often in polymedicated patients and with pluripathology, and on many occasions during prolonged periods of time. All these determinant factors sometimes make the safety profile of proton pump inhibitors disputable. In this respect all of them have been shown to have little adverse events and are safe in long-term treatment. The risk of drug interactions when prescribed in association with other drugs is low and their repercussion in the medical practice setting is quite exceptional as they require few dosage adjustments in patients with severe concomitant diseases and in elderly patients. Finally, their safety is high in pregnant women and in children, although further studies in this population are required to corroborate this evidence.