Post‐prandial reflux suppression by a raft‐forming alginate (Gaviscon Advance) compared to a simple antacid documented by magnetic resonance imaging and pH‐impedance monitoring: mechanistic assessment in healthy volunteers and randomised, controlled, double‐blind study in reflux patients

• Published in: Alimentary pharmacology & therapeutics Vol. 37; no. 11; pp. 1093 - 1102
• Main Authors: Sweis, R., Kaufman, E., Anggiansah, A., Wong, T., Dettmar, P., Fried, M., Schwizer, W., Avvari, R. K., Pal, A., Fox, M.
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell 01.06.2013
• Subjects: Adult; Aged; Alginates - therapeutic use; Aluminum Hydroxide - therapeutic use; Antacids - therapeutic use; Biological and medical sciences; Cross-Over Studies; Digestive system; Double-Blind Method; Drug Combinations; Electric Impedance; Esophageal pH Monitoring; Female; Gastroenterology. Liver. Pancreas. Abdomen; Gastroesophageal Reflux - diagnosis; Gastroesophageal Reflux - drug therapy; Humans; Hydrogen-Ion Concentration; Magnesium Oxide - therapeutic use; Magnetic Resonance Imaging; Male; Manometry; Medical sciences; Middle Aged; Pharmacology. Drug treatments; Postprandial Period; Silicic Acid - therapeutic use; Sodium Bicarbonate - therapeutic use; Treatment Outcome; Human; Evaluation; Healthy subject; Alginates; Document; Nuclear magnetic resonance imaging; Randomization; Surveillance; Double blind study; pH; Medical imagery; Impedance; Antiacid; Comparative study
• ISSN: 0269-2813; 1365-2036; 1365-2036
• DOI: 10.1111/apt.12318

Summary Background Alginates form a raft above the gastric contents, which may suppress gastro‐oesophageal reflux; however, inconsistent effects have been reported in mechanistic and clinical studies. Aims To visualise reflux suppression by an alginate–antacid [Gaviscon Advance (GA), Reckitt Benckiser, UK] compared with a nonraft‐forming antacid using magnetic resonance imaging (MRI), and to determine the feasibility of pH‐impedance monitoring for assessment of reflux suppression by alginates. Methods Two studies were performed: (i) GA and antacid (Alucol, Wander Ltd, Switzerland) were visualised in the stomach after ingestion in 12 healthy volunteers over 30 min after a meal by MRI, with reflux events documented by manometry. (ii) A randomised controlled, double‐blind cross‐over trial of post‐prandial reflux suppression documented by pH‐impedance in 20 patients randomised to GA or antacid (Milk of Magnesia; Boots, UK) after two meals taken 24 h apart. Results MRI visualized a “mass” of GA form at the oesophago‐gastric junction (OGJ); simple antacid sank to the distal stomach. The number of post‐prandial common cavity reflux events was less with GA than antacid [median 2 (0–5) vs. 5 (1–11); P < 0.035]. Distal reflux events and acid exposure measured by pH‐impedance were similar after GA and antacid. There was a trend to reduced proximal reflux events with GA compared with antacid [10.5 (8.9) vs. 13.9 (8.3); P = 0.070]. Conclusions Gaviscon Advance forms a ‘mass’ close to the OGJ and significantly suppresses reflux compared with a nonraft‐forming antacid. Standard pH‐impedance monitoring is suitable for clinical studies of GA in gastro‐oesophageal reflux disease patients where proximal reflux is the primary outcome.