Ranitidine, cimetidine, antacids, and gastro-oesophageal reflux: results of a 20-hour oesophageal pH study.

This study compared the effects of cimetidine, ranitidine, and antacids on oesophageal pH levels. Forty-five patients were confirmed as having a gastro-oesophageal acid reflux by 3-hour postprandial metered pH measurements. The 45 patients were randomly placed into three treatment groups; one group received cimetidine 1 g/day, the second received ranitidine 300 mg/day, and the third received 60 ml/day of an antacid. The patients were retested under treatment (3-hour postprandial metered pH and prolonged 20-hour metered pH). The 3-hour postprandial metered pH was then compared to the pretreatment tests. The 20-hour postprandial metered pH test was compared with the results from 43 control (untreated) subjects with gastro-oesophageal acid refluxes. The 3-hour postprandial comparison showed a significant decrease in acid reflux with all three treatment drugs. The 20-hour measurement demonstrated a significant decrease with all three drugs in the number of acid reflux incidences compared to the untreated control patients; the ranitidine group had a significant decrease in the percentage of time with acid pH. No significant differences appeared in the comparison of the records of the 45 treated patients except for the percentage of time below pH 2 for 20 hours which was significantly lower for ranitidine. All three treatments were effective with a clear advantage in favour of ranitidine.