Famotidine (Standard) is the standard substance of Famotidine, and it is applicable for quantitative analysis, quality control, and related research in biochemical experiments. Famotidine (MK-208) is a propanimidamide and histamine H2-receptor antagonist with antacid activity. As a competitive inhibitor of histamine H2-receptors located on the basolateral membrane of the parietal cell, famotidine reduces basal and nocturnal gastric acid secretion, resulting in a reduction in gastric volume, acidity, and amount of gastric acid released in response to various stimuli.