Antacids are substances that counteract stomach acidity. They are taken by mouth to relieve:

  • Heartburn
  • Sour stomach
  • Acid indigestion
  • Gas
  • Symptoms of stomach and duodenal ulcers

    Some antacids contain simethicone. Simethicone relieves the symptoms of excess gas. Those containing dimethicone will help reduce gas pains (flatulence). Some contain alginic acid. These help manage GERD (gastro-esophageal reflux disease).

    Antacids that contain aluminium or magnesium work by neutralizing gastric acid in order to reduce acid damage.

    Alginates such as sodium alginate work by forming a protective layer over the walls of the stomach and oesophagus.

    Antacids should be used only for occasional relief of the stomach. They should not be used for more than 14 days unless under medical supervision.

    If antacids are ineffective, medication such as H2 blockers or proton pump inhibitors may relieve the symptoms.

    H2 blockers may not relieve symptoms right away but they relieve symptoms for a longer period than antacids. Antacids can only provide fast short-term relief.

    Proton pump inhibitors stop the body’s production of acid and require 1 to 4 days to work.

    Poor response to medication may indicate an underlying medical condition.

    Types of antacids include:

  • Aluminium hydroxide such as Amphojel, AlternaGEL
  • Magnesium hydroxide e.g. Phillips’ Milk of Magnesia
  • Aluminium hydroxide and magnesium hydroxide e.g. Maalox, Mylanta
  • Aluminium carbonates gel such as Basajel
  • Calcium carbonate: these include Tums, Titralac, and Calcium Rich Rolaids
  • Sodium bicarbonate such as Bicarbonate of soda
  • Hydrotalcite such as Talcid

    Antacids and Pregnancy

    Those who are pregnant or breast-feeding need to use antacids with care. Some may pass into breast milk but there is no evidence that the intake of antacids through breast milk causes problems to the babies.

    Antacids should not be given to children under 6 years unless advised by the doctor.

    Other Precautions

    Aluminum may cause bone problems and Alzheimer's disease to get worse. Therefore, aluminium-containing antacids should not be used by elderly persons with such problems.

    Diabetic patients should take a sugar-free preparation.

    Side Effects of Antacids

    Antacids are relatively free of side effects when taken as directed. Occasionally, side effects may occur and these include,

  • Loss of appetite
  • Chalky taste
  • Constipation
  • Diarrhoea
  • Increased thirst
  • Stomach cramps
  • Muscle weakness

    Normally, antacids containing magnesium are likely to have a laxative action.

    Those containing aluminium may cause constipation.

    Magnesium carbonate is likely to cause belching. This is due to carbon dioxide being released from the compound in the stomach.