Kalpana Kalpana (Editor)


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An antacid is a substance which neutralizes stomach acidity, which in turn relieves heartburn, indigestion or stomach upset.


Medical uses

Antacids are available over the counter and are taken by mouth to quickly relieve occasional heartburn, the major symptom of gastroesophageal reflux disease and also indigestion. Treatment with antacids alone is symptomatic and only justified for minor symptoms.

Antacids are distinct from acid-reducing drugs like H2-receptor antagonists or proton pump inhibitors and they do not kill the bacteria Helicobacter pylori, which causes most ulcers.

Side effects

Versions with magnesium may cause diarrhoea, and brands with calcium or aluminium may cause constipation and rarely, long-term use may cause kidney stones. Long-term use of versions with aluminium may increase the risk for getting osteoporosis.

Mechanism of action

When excessive amounts of acids are produced in the stomach the natural mucous barrier that protects the lining of the stomach can damage the esophagus in people with acid reflux. Antacids contain alkaline ions that chemically neutralize stomach gastric acid, reducing damage and relieving pain.


Antacids may be formulated with other active ingredients such as simethicone to control gas or alginic acid to act as a physical barrier to acid.


Eno is an antacid brand whose main ingredients are sodium bicarbonate, sodium carbonate, and citric acid; it is sometimes used as baking powder. Eno was first marketed by James Crossley Eno (1827–1915). The legend says that his idea for the product arose while he was working at the pharmacy of an infirmary in Newcastle where Dennis Embleton worked, and that Embleton often prescribed an effervescent drink made by mixing sodium bicarbonate and citric acid in water, and that Eno adopted this beverage from Embleton. However, Eno opened a pharmacy where he made the mixture in 1852, a year before Embleton came to work at the infirmary, and such mixtures were common at the time. Eno gave away his branded mixture to sea captains at the port, and in this way Eno's became a brand known around the world; by 1865 he had to move to a bigger facility, and he formally founded the company Eno's "Fruit Salt" Works in 1868. In 1878 Eno moved the business to Hatcham where the factory employed 50 people by 1884.

Eno was advertised heavily, like all patent medicines were at that time. In 1883 it was advertised as a cure for cholera and in 1892 for "keeping blood pure and free from disease", prevention of diarrhea, and many other conditions. By 1928 the company had factories in England, Canada, France, Germany, Spain, and the US; that year the company was acquired by International Proprietaries, a company that had been established by Canadian businessman Harold F. Ritchie. International Proprietaries was eventually renamed Eno, and in 1938 the business was bought by Beecham for its products as well as its international marketing force. As the pharmaceutical industry transitioned from selling cure-all patent medicines to selling drugs in the 1950s, Eno was one of a handful of products that were retained in the industry.


Antacid Wikipedia

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