In the stomach, over production of acid causes irritation, constipation and pain. In severe cases, ulcers are developed in the stomach. Until 1970, only treatment for acidity was administration of antacids, such as sodium hydrogen carbonate (SHC) and a mixture of aluminium and magnesium hydroxide. Some common antacids are- sodium hydrogen carbonate (NaHCO3), ranitidine, omeparazole, rebprazole, rolaid (CaCO3 and Mg(OH)2), etc. Novestrol (ethylnylestradiol) is used as contraceptive drug. Chlordiazepoxide is used as tranquiliser.
Hence, the antacids are - 1, 4 and 5.