title: Gaviscon Double Action Liquid (antacid & alginate) is more effective than antacid in controlling post-prandial oesophageal acid exposure in GERD patients: a double-blind crossover study.
abstract: BACKGROUND
  Recent studies have shown that Gaviscon Double Action Liquid (a combination alginate-antacid) administered post-prandially co-localises with the acid pocket, the 'reservoir' for post-prandial acid reflux.
  
  
  OBJECTIVE
  To compare the effectiveness of Gaviscon Double Action Liquid to an equivalent strength antacid without alginate in controlling post-prandial acid reflux in GERD patients.
  
  
  METHODS
  Fourteen GERD patients undertook two 3.5-h high-resolution manometry/pH-impedance studies during which they ate a standardised meal. In a double-blinded randomised crossover design they then took Gaviscon or CVS brand antacid, each with ~18 mmol/L acid neutralising capacity. The primary outcome was distal oesophageal acid exposure; secondary outcomes were number of reflux events, proximal extent of reflux, nadir pH of the refluxate, mechanism of reflux and reflux symptoms scored with a validated instrument.
  
  
  RESULTS
  Ten patients completed the study. Gaviscon studies had significantly less distal oesophageal acid exposure and greater nadir refluxate pH in the 30-150 min post-prandial period than antacid studies. There were no differences in the number of reflux events (acid or weakly acidic) or the number of proximal reflux events (15-17 cm above the LES) with either study medication.
  
  
  CONCLUSIONS
  Gaviscon Double Action Liquid is more effective than an antacid without alginate in controlling post-prandial oesophageal acid exposure. However, the number and spatial distribution of reflux events within the oesophagus are similar. This suggests that Gaviscon main effectiveness relates to its co-localisation with and displacement/neutralisation of the post-prandial acid pocket, rather than preventing reflux.
authors.affiliation: Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA; Department of Gastroenterology, Academic Medical Center Amsterdam, Amsterdam, The Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: De Ruigh
authors.forename: S
authors.initials: S
authors.lastname: Roman
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: J E
authors.initials: JE
authors.lastname: Pandolfino
authors.forename: P J
authors.initials: PJ
authors.lastname: Kahrilas
mesh_terms: D000328:Adult; D000464:Alginates / Q000627:therapeutic use*; D000536:Aluminum Hydroxide / Q000627:therapeutic use*; D000863:Antacids / Q000627:therapeutic use*; D002119:Calcium Carbonate / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004338:Drug Combinations; D017097:Electric Impedance; D004947:Esophagus / Q000187:drug effects; D005260:Female; D005744:Gastric Acid / Q000378:metabolism; D005764:Gastroesophageal Reflux / Q000188:drug therapy*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008276:Magnesium Hydroxide / Q000627:therapeutic use*; D008297:Male; D008365:Manometry; D008875:Middle Aged; D019518:Postprandial Period; D012824:Silicic Acid / Q000627:therapeutic use*; D017693:Sodium Bicarbonate / Q000627:therapeutic use*
chemical_list: D000464:Alginates; D000863:Antacids; D004338:Drug Combinations; D012824:Silicic Acid; D000536:Aluminum Hydroxide; C007829:alginate, aluminium hydroxide, magnesium trisilicate, sodium bicarbonate drug combination; D017693:Sodium Bicarbonate; D002119:Calcium Carbonate; D008276:Magnesium Hydroxide