鹽酸雷尼替丁抑制劑Ranitidine Hydrochloride?is a member of the class of?histamine?H2-receptor antagonists with antacid activity.?Ranitidine?is a competitive and reversible inhibitor of the action of?histamine, released by enterochromaffin-like (ECL) cells, at the?histamine?H2-receptors on parietal cells in the stomach, thereby inhibiting the normal and meal-stimulated secretion of stomach acid. In addition, other substances that promote acid secretion have a reduced effect on parietal cells when the H2 receptors are blocked.