A randomized, double-blind, placebo-controlled, multicenter, parallel group, dose-ranging study of ranitidine was conducted to determine its effect for relief of episodic heartburn.

Adult outpatients having heartburn, which responded to antacid therapy, at least seven times a week, over the previous 2 weeks, were included in the trial.

Patients who successfully completed a 1-week single-blind placebo run-in phase and did not have adequate relief in over 50% of heartburn episodes were randomly allocated to a 1-week, double-blind treatment phase and were given ranitidine in doses of 25, 75 or 125 mg, or placebo. A total of 577 patients were randomized. Of these, 566 patients had at least one evaluable heartburn episode and participated in the intention-to-treat analysis.

• All three dosage regimens of ranitidine were found to be statistically significantly superior to placebo in terms of providing relief from episodic heartburn for the first episode (P < 0.002), last episode (P</=0.004), as well as all episodes combined (P < 0.001).
• A larger proportion of patients achieved sustained relief (relief within 60 min of taking the drug, persisting through the 4-h evaluation period) with the 75 mg and 125 mg doses for each individual episode (43-56% for 75 mg and 42-57% for 125 mg) compared to ranitidine 25 mg dose (35-50%), or placebo (21-29%).
• Patients undergoing treatment with the 75 mg and 125 mg doses took statistically lesser rescue antacids compared to those treated with placebo for the first episode.
• The incidence of adverse events was similar in all treatment groups.

All three dosage regimens of ranitidine were found to be safe and superior to placebo in providing adequate relief for heartburn.

The onset of relief with ranitidine was progressive and evident by 30 minutes.

All three doses of ranitidine were well tolerated, and the adverse event profiles were similar placebo.

Table. Proportion of patients achieving sustained relief for each individual episode

Source: Pappa KA, Buaron K, Payne JE, et al. An evaluation of increasing doses of ranitidine for treatment of heartburn. Aliment Pharmacol Ther. 1999 Apr;13(4):475-81.