Antacids: Uses, Working, Side Effects, and Precautions

Posted On Dec 02, 2022

gastroenterology hospital in Bangalore

Antacids are agents that reduce the amount of acid in the stomach. They provide relief from certain digestive disorders such as heartburn, acid reflux and indigestion by reducing or preventing the secretion of stomach acid. They are available as over-the-counter medications in two forms - liquid and tablets. While antacids help relieve symptoms of digestive disorders, it’s best if you take them as needed. Overuse of antacids can cause excess calcium in the body which can result in problems like nausea, vomiting, and kidney stones. Moreover, over usage of antacids can lead to alkalosis (a condition in which your body doesn’t make enough acid to function properly). 

Antacids and Their Uses

Antacids are a group of medicines used for quick relief from symptoms of too much stomach acid such as stomach upset, heartburn, and acid indigestion. An antacid is a combination of various compounds with various salts of calcium, magnesium, and aluminium as active ingredients such as Aluminum Hydroxide, Magnesium Carbonate, and Magnesium Trisilicate. They are sold under different brand names in India. The most common and widely popular antacids examples are ENO, Digene, Gelusil, Mucaine gel, Digirest, Gaviscon, Dabur Pudin Hara, Himalaya Gasex, and BIOCIL MPS syrup. 

Antacids are very useful for reducing symptoms of 

  • acid reflux, also known as gastro-oesophageal reflux disease (GERD). It may cause heartburn or inflammation of the oesophagus.

  • stomach or duodenum ulcers

  • Indigestion or dyspepsia 

In the video below, Dr. Suresh Shenoy, Consultant - Gastroenterologist, KMC Hospital Mangalore throws light on the treatment options available for GERD.

Antacids are different from other acid blocker agents like H2 blockers and proton pump inhibitors (PPI). An antacid is a fast-acting agent that doesn’t cure the underlying cause of the disease. It just neutralises stomach pH, thereby decreasing the exposure of the oesophagal mucosa to acid from the stomach during episodes of reflux. Moreover, the effects of antacid remain for about 30 to 60 minutes, whereas the duration of action of PPI can last 24 hrs up to 3 days. Consult with our best gastroenterologist in Bangalore to know more about the treatment.

How do Antacids Work?

The way antacids work is by neutralising (counteracting) the stomach acid. Antacids contain metallic salts in them which are basic (alkaline) in nature. When they react with stomach acid, the pH gets neutralised. Neutralisation describes the outcome of an acid and base reaction. This neutralisation lessens the corrosiveness of the stomach contents. This may lessen the discomfort brought on by ulcers and the burning sensation brought on by acid reflux. 

Their working mechanism shows that they do not cure the underlying cause of heartburn or indigestion. Suppose your symptoms of stomach acid do not go away after taking antacids. In that case, it’s better to consult a doctor and take more advanced medicines such as Histamine H2-receptor antagonists or proton pump inhibitors. Acid neutralisation can cause gas build-up in the digestive tract. Therefore, antacids often contain agents like simethicone which helps break up gas bubbles in the gut and provides relief from flatulence. 

Side Effects of Antacids

Antacids generally do not pose any side effects or serious medical threats. However, since they are made to provide quick relief from stomach acid symptoms, you should not take them as a treatment option. Also, some side effects are observed in a small number of users with regular and excess usage of antacids. Side effects might include diarrhoea, constipation, belching, and swelling in the feet, ankles and hands. 

Antacids can be laxative or constipating in nature depending on the alkaline salt contained in them. Antacids with magnesium tend to be laxative, whilst those with aluminium tend to be constipating. Hence choose an antacid that contains both magnesium and aluminium as the effects could be balanced out, minimising any potential negative consequences.

People with certain medical conditions such as heart failure and kidney failure should consult their doctors before taking any kind of antacids. These medicines often contain a lot of sodium and aluminium as well as electrolytes. This can lead to toxicity and electrolyte imbalance.

In the following video, Dr. Manish Kak, Consultant - Gastroenterology, Manipal Hospital Ghaziabad discusses the types, causes, symptoms and treatments for various common stomach issues.

Precautions While Taking Antacids

Although antacids are the go-to medicine for mild symptoms of acid reflux and indigestion, they can cause problems if taken in excess or with other medications. Here are some precautions you need to take while taking antacids:

  • Consult a doctor immediately if the symptoms don’t go away even after taking antacids for 2 weeks. 

  • Always talk to your doctor before taking antacids if you have kidney or liver problems or if you are on a low-sodium diet. 

  • Antacids may interfere with certain thyroid drugs such as Levoxyl or Synthroid (levothyroxine) or the blood thinner Coumadin or Jantoven (warfarin). So if you are taking these medications, don’t take antacids unless prescribed by your doctor. To know more about the precautions, visit our gastroenterology hospital in Bangalore.

  • If you are pregnant, avoid taking antacids that contain high amounts of sodium.

  • Children should not take antacids without consultation from a paediatrician.


Here are some frequently asked questions on antacids and their uses and side effects:

Q.1: What are commonly used antacids?

A: Most commonly used antacids are weak bases such as sodium bicarbonate, magnesium hydroxide, magnesium carbonate and aluminium hydroxide.

Q.2: When should I take antacids?

A: You should take antacids when you have symptoms of heartburn or indigestion. You can also take an antacid one hour after eating, which is when you might experience symptoms of heartburn.

Q.3: Are antacids safe?

A: Antacids are quite safe and do not cause side effects in most cases. However, people with kidney or heart failure conditions should consult their doctor before they take antacids as they can interfere with other medications and cause complications.

Q.4: What is a natural antacid remedy?

A: Natural antacids are those which we can prepare at home to get relief from symptoms of indigestion and acid reflux. The best natural antacid remedies are:

  • Sodium bicarbonate (baking soda)

  • Milk

  • Chewing gum

  • Gingerroot

  • Acids such as apple cider vinegar and lemon juice

Q.5: Do antacids have side effects?

A: Occasional small doses of antacids do not pose any side effects or serious health threats. However, patients with kidney or heart diseases should consult their doctor before taking antacids. In rare cases, there are some side effects observed in a few people such as diarrhoea, belching, and nausea.

Department of Gastrointestinal Science

Manipal Hospitals

Call Us