The effects of 75 mg HOE 760, a novel H2-receptor antagonist, on daytime peptone-stimulated and nocturnal gastric acid output in healthy volunteers

The effects of roxatidine acetate (HOE-760) on 24-hour intragastric acidity in healthy volunteers: comparison with ranitidine and placebo

In a series of double-blind randomized studies in normal volunteers using continuous intragastric pH monitoring, the effects of different dosage regimens of roxatidine, a new H2-receptor antagonist, were compared with placebo and ranitidine. Roxatidine acetate, 75 mg twice daily, decreased median 24 h gastric acidity from pH 1.6 to 3.2 and median nocturnal acidity from 1.5 to 3.0. Roxatidine acetate, 150 mg at bedtime, raised median 24 pH of the same 17 subjects to 2.4 and nocturnal pH to 5.9. In another series of experiments, 150 mg roxatidine acetate at bedtime was as effective as ranitidine 300 mg nocte raising median nocturnal pH (14 volunteers) from 1.4 to 6.65 compared to 6.7, respectively. However, when drugs were taken after the evening meal (post cenam nocte, pcn) roxatidine acetate 150 mg was less potent than ranitidine 300 mg with median night-time pH rising from 1.3 to 3.2 and 4.0, respectively, in 28 volunteers. Roxatidine acetate 300 mg pcn raised the pH to 4.9 suggesting that roxatidine is 1-2 times as potent as ranitidine, on a milligram-for-milligram basis.

Effect of roxatidine acetate on daytime and night-time peptone-stimulated gastric acid secretion

A double-blind, randomised, crossover study in 12 healthy volunteers was performed to assess the effects of roxatidine acetate 75 mg or placebo administered at 8 am and 9 pm on peptone-stimulated hydrochloric acid secretion. In comparison to placebo, roxatidine acetate produced an average reduction of daytime hydrochloric acid output of 86% and 32%, respectively, for the 4- to 6-hour and 10- to 12-hour post-drug administration phases. In addition, roxatidine acetate produced reductions in nocturnal hydrochloric acid output of 75 to 92% with an associated rise in intragastric pH of around 2 units compared to placebo. No side effects or clinically significant alterations in haematological or biochemical values were reported following roxatidine acetate administration. These results suggest that roxatidine acetate is a potent and effective inhibitor of day and night-time intragastric acid secretion.