Antacids are substance which neutralizes stomach acidity and is used to relieve heartburn, indigestion or an upset stomach. Some antacids have been used in the treatment of constipation and diarrhea. Currently marketed antacids contain salts of aluminum, calcium, magnesium, or sodium. Some preparations contain a combination of two salts, such as magnesium carbonate and aluminum hydroxide.
Antacids are available over the counter and are taken by mouth to quickly relieve occasional heartburn, the major symptom of gastroesophageal reflux disease and indigestion. Treatment with antacids alone is symptomatic and only justified for minor symptoms. Alternative uses for antacid include constipation, diarrhea, hyperphosphatemia, and urinary alkalization. Some antacid are also used as an adjunct to pancreatic enzyme replacement therapy in the treatment of pancreatic insufficiency.
Non-particulate antacid pills (sodium citrate, magnesium trisilicate) increase gastric pH with little or no effect on gastric volume, and therefore may see some limited use in pre-operative procedures. Sodium citrate should be given within 1 hour of surgery to be the most effective.
Formulations containing magnesium salts may cause diarrhea, whereas those containing calcium or aluminum may cause constipation. Rarely, long-term use of calcium carbonate may cause kidney stones. Long-term use of antacids containing aluminum may increase the risk of developing osteoporosis. In vitro studies have found a potential for acid rebound to occur due to antacid pills overuse, however the significance of this finding has been called into question
When an excess amount of acid is produced in the stomach, the natural mucous barrier that protects the lining of the stomach can degrade, leading to pain and irritation. There is also potential for the development of acid reflux, which can cause pain and damage to the esophagus. Antacids contain alkaline ions that chemically neutralize stomach gastric acid, reducing damage to the stomach lining and esophagus, and relieving pain. Some antacid pills also inhibit pepsin, an enzyme that can damage the esophagus in acid reflux.