Continuous 24-hour intragastric pH monitoring in the evaluation of the effect of a nightly dose of famotidine, ranitidine and placebo on gastric acidity of patients with duodenal ulcer.

In 11 duodenal ulcer patients, the antisecretory effects of bedtime famotidine 40 mg were compared to those obtained with ranitidine 300 mg and placebo by means of continuous 24-hour intragastric pH monitoring. The 24-hour areas under the curve of pH profiles of the two H2 blockers were significantly different from those related to placebo (p approximately 0 for ranitidine and p = 0.00001 for famotidine), but not from each other (p = 0.51). Onset and duration of the famotidine action, however, were respectively earlier and longer lasting (12 vs. about 9 h) than those of ranitidine. Famotidine was also significantly superior (p approximately 0) to ranitidine in keeping intragastric pH at high values (especially those comprised between 6 and 8 pH units), although theoretically equipotent doses of the two H2 antagonists were used.