How Do Antacids Work and Types of Antacids, Side Effects of Antacids

Antacid are mainly used to treat symptoms of dyspepsia (indigestion/heartburn)when stomach acid causes inflammation or ulceration of the lying of the stomach, duodenum or gullet.

Excess of acid is neutralized in the stomach with antacid tablets. The main constituents of antacids are aluminum and magnesium hydroxide. Alginates such as sodium alginates are other common ingredients of indigestion and heartburn remedies. Sometimes, dimethicone is added to an antacid as an antifoaming agent to relieve wind. Antacids work by forming a protactive coating on these walls of stomach and gullet.

Systemic antacids

Sodium bicarbonate

It is used an antacid in the treatment of indigestion and heartburn. it mainly acts by neutralizing HCL produced by gastric parietal cells. It gets rapidly cleared from the stomach and presents both as alkali and sodium load.

Non -Systemic antacids

Aluminium Hydroxide

It is most commonly used in treatment of heartburn, gastritis and peptic ulcer. It is a week and slowly acting antacid, and its neutralizing action is slowed down by food in the stomach. It is a demulcent and protects ulcerates.

Calcium Carbonate

This preparation contains active ingredients CaCO3. It is useful in temporary relief of occasional indigestion and heartburn. It is a potent and rapidly acting neutralizer which slowly liberates CO2In stomach, causing distention and discomforts. Occasional effects like loss of appetite, headache, constipation, dizziness, and vomiting may occur. Caution should be taken in any kidney disease.


Activated dimethicone is an antifoaming agent.


It neutralizes and reduce stomach acid relieving heartburn and indigestion. it is used to treat an upset stomach, ulcer, hiatal hernia and other digestive disorders .Loss of appetite, diarrhoea ,or constipation may occur .

Magnesium Hydroxide

It is used as an antacid for short-term relief of stomach upset. It is poorly water – soluble and has low alkalinity. It also helps in short – term treatment of constipation.

Magnesium Oxide

It is relieved heartburn, some stomach acid indigestion. It comes as a tablet and capsule to be taken orally. Do not take as an antacid more than 2 weeks unless doctor tells. Side effects are cramping, diarrhoea, itching, rash, dizziness, or light-headedness, weakness and vomiting.

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