Effects of roxatidine acetate on 24-hour gastric acidity. Early evening versus bedtime administration in healthy subjects.

The gastric antisecretory activity of roxatidine acetate was studied on 24-hour intragastric pH in 12 healthy male volunteers. The study was randomised, double-blind and double-dummy where either roxatidine acetate 150 mg as a slow release granulated formulation or placebo were administered at 7.30 pm or 10 pm. Roxatidine acetate 150 mg produced a significant decrease in the number of hours during which gastric acidity ranged between pH 1.5 and 4.0 which was consistent with the pharmacokinetic profile of the drug. There was no significant difference between the median intragastric pH values for early evening and bedtime administration of roxatidine acetate. The present data confirm that roxatidine acetate 150 mg inhibits gastric acid secretion but while a single evening dose is effective in controlling intragastric pH the results suggest there is no clear advantage in an early evening dose compared with a bedtime dose.