Antacid

[3] 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.

[6] Conventional effervescent tablets contain a significant amount of sodium and are associated with increased odds of adverse cardiovascular events according to a 2013 study.

[9] In vitro studies have found a potential for acid rebound to occur due to antacid overuse, however the significance of this finding has been called into question.

[2][13] Antacids do not directly inhibit acid secretion, and thus are distinct from acid-reducing drugs like H2-receptor antagonists or proton pump inhibitors.

[19] Chewable tablets are one of the most common forms of antacids, most frequently made from carbonate or hydroxide salts, and are readily available over the counter.

This process reduces the concentration of H+ ions in the stomach, raising the pH and neutralizing the acid.

[8]: Figure 1  Common carbonate salts available in tablet form include those of calcium, magnesium, aluminum, and sodium.

[21][22][23] Common ingredients include citric acid and sodium bicarbonate, which react when in contact with water to produce carbon dioxide.