Rapid onset of effect of sodium alginate on gastro-oesophageal reflux compared with ranitidine and omeprazole, and relationship between symptoms and reflux episodes.

The objective of the open, randomised, four-period crossover study was to compare the time of onset of effect of sodium alginate (SA), omeprazole, ranitidine and control, based on oesophageal and intragastric pH and to determine any correlation between reflux symptoms and episodes in volunteers suffering from occasional gastro-oesophageal reflux. SA showed extensive prevention of acid exposure in the oesophagus compared with other treatments during the first hour. Overall, SA was more effective than control or omeprazole and comparable with ranitidine. There was little evidence of association between 'oesophageal' symptoms and reflux episodes, but associations between 'gastric' symptoms and acidity in the oesophagus, fundus and corpus were apparent. For an immediate reduction in gastro-oesophageal reflux into the oesophagus and gastric acidity during the first hour, SA was significantly superior to control, ranitidine and omeprazole. Ranitidine showed a superior effect from 2 h, consistent with its pharmacological mode of action.