What is antacid?

Antacids are medicines used in reducing stomach disturbance caused by gastritis or heartburn.

How antacid works?

Antacid works by reducing the acidity in the stomach.

It will interact with stomach fluids containing hydrochloric acid (a liquid which is secreated by stomach for food digestion thus will increase stomach’s pH value to achive neutral level.

Naturally, our stomach acidity level is around pH value of 1.5 and 3.5.

How to take antacid?

Antacids are available in tablet and liquid form. They are taken orally before food.

The recommended doses for adult are one or two tablets and it is important to discuss with doctor or pharmacist if used with other medicines. Tablets must be chewed or crushed to increase absorption rate into the body. Do not double the dose or take more than recommended doses unless directed by doctor.

While in liquid suspension, the suggested dose is 15ml for adult. Make sure that you follow the recommended doses. It is advice to shake the bottle well before taking any doses.

If you are having peptic ulcer disease (Picture 1; wound at stomach lining), continue to take your medicine as directed by the doctor.


Picture 1: Peptic ulcer occur in stomach

Where I can get this medicine?

Antacids are available at most of retail pharmacies and purchased can be made without prescription. Some examples of antacids available at retail pharmacies are:

  1. Mixture of sodium alginate, sodium bicarbonate, calcium carbonate

    Available in liquid form

  2. Mixture of magnesium oxide, aluminium dioxide, dimethylpolysiloxane

    Mixture of magnesium oxide, aluminium dioxide, dimethylpolysiloxane

There are several types of antacids available at Ministry of Health hospitals and clinics such as:

  1. Magnesium trisilicate

    Available in tablet and liquid form

    Adult dose:

    • Tablet form – can take 1 to 2 tablets that need to be chewed before consume and can be taken up to 6 times daily before food.

    • Liquid form – 15ml or 1 tablespoon can be taken up to 6 times daily before food.

    Children dose: age 6 years and above, 1 tablet taken 3-4 times daily.

  2. Mixture of Sodium Bicarbonate, Magnesium Carbonate, Tincture Cardamom Compound

    Adult dose: 10-20 ml taken 3 times daily.

  3. Sodium Bicarbonate Mixture (Pediatric)

    Available in liquid form

    Children dose: 5ml for age 1 year and below, 10ml for age 1-5 years: taken 4 to 6 times daily.

  4. Aluminium Hydroxide 600mg

    Available in tablet form

    Adult dose: 600mg – 1200mg taken 4 times daily including before going to bed.

What if I forget to take the dose?

  • Immediately take the dose as soon as you remember.

  • If the time for next dose is too near (around 1 to 2 hour), wait until the next dose and ignore skip the missed dose.

  • Do not take double the dose.

How long will it takes for the antacid to take action?

Antacid acts fast, around 10 to 15 minutes from the time it was taken.

The stomach disturbances usually will resolve in 20 minutes time after consume the antacid.

Why do I need to take antacid?

  • Antacid are prescribe for patients that are experiencing stomach ache and heart burn.

  • Antacid are also use as adjuvant with pain relievers medications that have potential in causing gastritis.

  • For patients with peptic ulcer, antacid should be taken within a longer time until the ulcer is healed.

What are the side effects taking antacid?

All medicines may have some unwanted side effects. Sometimes they are serious, but most of the time they are not. Tell your doctor or pharmacist if you have any side effects which are severe or persist.

Common side effects include:

  • Irregular heartbeats

  • Weakness or severe fatigue, or

  • Persistent stomachache

If you are having side effects and they persist either:

  • Constipation

  • Persistent diarrhea

  • Severe numbness of the tongue/loss of taste or

  • White stools

During taking antacid, STOPS immediately from taking it and seek for advice and see a doctors.

How to store this antacid?

  • Store at room temperature and in a dry place

  • Protect away from light

  • Do not keep the liquid suspension in the refrigerator

  • Keep out of reach of children

  • Do not share medication with others

  • Do not use/take after the expiry date has passed

  • Seek advice from doctor or pharmacist on how to dispose expired antacid

  • OR return the expired or unused antacid to the nearest pharmacy counters.

Precautions before taking this medication

  • Inform your doctor if you are pregnant or breastfeeding.

  • Make sure you inform your doctor if you are having kidney or liver problems

  • If you are on dialysis, DO NOT take any antacids of various brands because some brands contains substances that may interfere with the process of dialysis. Dialysis patients should seek doctor’s advice.

  • Antacid may contains high salt content. Consult your doctor if you are on low-salt diet programme.

Last Reviewed : 23 April 2014
Writer : Mohd Hadafi bin Mohd Yasim
Reviewer : Che Pun bt. Bujang