Why are cimetidine and ranitidine better antacids than sodium hydrogen carbonate or magnesium or aluminium hydroxide ?

Explanation

Excessive intake of sodium hydrogen carbonate can make the stomach alkaline and trigger the production of even more acid. Metal hydroxides are better alternatives because of being insoluble these do not increase the pH above neutrality. However, these treatments control only symptoms and not the cause. Therefore, with these metal salts, the patients cannot be treated easily. Cimetidine and ranitidine are better antacids because they control the cause of hyperacidity. It is observed that histamine stimulates the secretion of pepsin and hydrochloric acid in the stomach. Drugs like cimetidine and ranitidine prevent the interaction of histamine with the receptors present in the stomach wall. This result in release of lesser amount of acid, thus controlling the hyperacidity.