: Episodic heartburn is a common problem, affecting over 40 million Americans. Although omeprazole provides excellent acid suppression when used daily, the use of omeprazole as on-demand therapy for episodic symptoms has not been extensively studied.


: To compare the onset and duration of post-prandial gastric acid suppression by omeprazole (10 and 20 mg) or ranitidine (75 and 150 mg) taken as single doses in healthy volunteers.


: Twenty-four healthy volunteers (14 male, 10 female, mean age 33.4 years, range 18–56 years) were given ranitidine (RAN) 75 mg or 150 mg vs. omeprazole (OME) 10 mg or 20 mg when pH returned to below 2 after breakfast, in a randomized open label crossover design, with a washout of at least 2 days between medications. Intragastric pH was monitored for 6 h. The time between drug ingestion and rise of gastric pH > 3 and 4, and total time pH remained > 3 and 4 during the 6 h post drug, was compared between groups using two way ANOVA and Wilcoxon matched pairs test.


: The median time needed to pH > 4 was 204.5 min for RAN 75 mg, 186 min for RAN 150 mg and > 360 min for both OME 10 and 20 mg (< 0.001 between the four groups). The median time that pH remained > 4 was 93 min for RAN 75 mg, 143.5 min for RAN 150 mg and 0 min for both OME 10 and 20 mg (< 0.001 between the four groups). Both doses of RAN were significantly superior to both doses of OME, although no significant difference was found between the high and the low doses of either drugs. Similar results were found for pH > 3.


: Ranitidine 75 or 150 mg provides more rapid increase in gastric pH to > 3 and > 4 compared to omeprazole 10 or 20 mg when taken at the end of the post-prandial period. These data suggest that ranitidine may be more effective for episodic post-prandial heartburn than omeprazole.