Gastric secretion in response to a meal 12-13 h after ranitidine.

In a recent study we demonstrated a marked inhibition of basal gastric acid secretion 12-14 h after oral administration of 150 mg ranitidine. This study investigates the effect of ranitidine on meal-evoked secretion, time interval between drug administration and measurements remaining the same as in a former study. Under the present conditions 150 mg ranitidine had no effect on acid secretion and enhanced pepsin secretion. The results indicate that the effect of the H2-receptor antagonist is surmountable by meal stimulation. The concentrations of ranitidine in basal gastric juice was approximately the same as in blood. The gastric excretion of ranitidine did not increase by meal stimulation and was approximately 0.5% of the excretion in urine.