title: An alginate-antacid formulation (Gaviscon Double Action Liquid) can eliminate or displace the postprandial 'acid pocket' in symptomatic GERD patients.
abstract: BACKGROUND
  Recently, an 'acid pocket' has been described in the proximal stomach, particularly evident postprandially in GERD patients, when heartburn is common. By creating a low density gel 'raft' that floats on top of gastric contents, alginate-antacid formulations may neutralise the 'acid pocket'.
  
  
  OBJECTIVE
  To assess the ability of a commercial high-concentration alginate-antacid formulation to neutralize and/or displace the acid pocket in GERD patients.
  
  
  METHODS
  The 'acid pocket' was studied in ten symptomatic GERD patients. Measurements were made using concurrent stepwise pH pull-throughs, high resolution manometry and fluoroscopy in a semi-recumbent posture. Each subject was studied in three conditions: fasted, 20 min after consuming a high-fat meal and 20 min later after a 20 mL oral dose of an alginate-antacid formulation (Gaviscon Double Action Liquid, Reckitt Benckiser Healthcare, Hull, UK). The relative position of pH transition points (pH >4) to the EGJ high-pressure zone was analysed.
  
  
  RESULTS
  Most patients (8/10) exhibited an acidified segment extending from the proximal stomach into the EGJ when fasted that persisted postprandially. Gaviscon neutralised the acidified segment in six of the eight subjects shifting the pH transition point significantly away from the EGJ. The length and pressure of the EGJ high-pressure zone were minimally affected.
  
  
  CONCLUSIONS
  Gaviscon can eliminate or displace the 'acid pocket' in GERD patients. Considering that EGJ length was unchanged throughout, this effect was likely attributable to the alginate 'raft' displacing gastric contents away from the EGJ. These findings suggest the alginate-antacid formulation to be an appropriately targeted postprandial GERD therapy.
authors.affiliation: Department of Medicine, Feinberg School of Medicine, Northwestern University, 676 St. Clair Street, Chicago, IL 60611-2951, USA. monika.kwiatek@gmail.com
authors.forename: M A
authors.initials: MA
authors.lastname: Kwiatek
authors.forename: S
authors.initials: S
authors.lastname: Roman
authors.forename: A
authors.initials: A
authors.lastname: Fareeduddin
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*; D004338:Drug Combinations; D005260:Female; D005764:Gastroesophageal Reflux / Q000188:drug therapy*; D006356:Heartburn / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D012824:Silicic Acid / Q000627:therapeutic use*; D017693:Sodium Bicarbonate / Q000627:therapeutic use*; D016896:Treatment Outcome
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