Indigestion medicines

Published by Bupa's Health Information Team, July 2011.

This factsheet is for anyone taking indigestion medicines, or who would like information about them.

Indigestion (dyspepsia) is the term used to describe pain or discomfort in the upper abdomen (tummy) or chest that generally occurs soon after meals. Indigestion medicines relieve these symptoms.

Why would I take indigestion medicines?

Indigestion can cause pain and discomfort in your upper abdomen or chest after you eat. You might feel a burning sensation in your chest, known as heartburn.

Indigestion can happen when your stomach acids (which digest your food) leak back into your oesophagus (the pipe that goes from your mouth to your stomach) and cause irritation. This is known as backflow or acid reflux, and the condition is called gastro-oesophageal reflux disease. Other problems that can cause indigestion include a hiatus hernia and an infection with a type of bacteria called Helicobacter pylori (H. pylori).

What are the main types of indigestion medicines?

There are four main types of medicine for indigestion and gastro-oesophageal reflux disease. These are:

  • antacids and alginates
  • H2-blockers
  • proton pump inhibitors
  • prokinetics

How do indigestion medicines work?

The types of medicines for indigestion work in different ways.

Antacids and alginates

Antacids usually contain aluminium or magnesium. These are alkalis, which work by neutralising stomach acid.

Alginates, such as sodium alginate, are another common ingredient of indigestion medicines. These work by forming a protective layer that floats on the surface of your stomach to reduce acid reflux.

Some indigestion medicines contain both antacids and alginates, and other ingredients such as simeticone and peppermint oil (both for wind and bloating). These are especially useful for people with irritable bowel syndrome. 


A chemical called histamine (which is produced naturally by your body) causes cells in your stomach to make acid. H2-blockers can stop histamine from working on these cells and so lower the amount of acid produced in your stomach.

Proton pump inhibitors

Proton pump inhibitors work by completely blocking the production of stomach acid. They do this by shutting down (inhibiting) a system in your stomach known as the proton pump. Proton pump inhibitors are used for treating:

  • heartburn symptoms caused by acid reflux
  • H. pylori infections (in combination with antibiotics)
  • peptic ulcers


These medicines work by helping food pass more quickly through your stomach. They are used if you still have symptoms after taking the medicines above.

How to take indigestion medicines

Antacids and alginates

Antacids come as tablets, capsules, liquids or powders. Liquid preparations are more effective than tablets and capsules but may be less convenient to carry around.

It’s best to take antacid-containing medicines when you get, or expect to get, indigestion symptoms. This is usually about an hour after a meal and when you go to bed. 


You can buy some H2-blockers from your pharmacist without a prescription. Your GP may prescribe medicines from this group in stronger doses and for longer courses if you have digestive problems such as gastro-oesophageal reflux disease and ulcers.

H2-blockers come as tablets and liquids. To relieve indigestion, take H2-blockers as soon as you get symptoms. 

Proton pump inhibitors

Omeprazole is a common type of proton pump inhibitor medicine used to treat indigestion. You can buy it from your pharmacist without a prescription. Usually you take two 10mg tablets, with plenty of liquid, once a day before a meal. You can use this medicine for 28 days – if your symptoms continue for longer than this, ask your GP for advice.

Your GP may prescribe omeprazole or another proton pump inhibitor to treat stomach and duodenal ulcers. They are also used to relieve symptoms of gastro-oesophageal reflux disease, and as part of the treatment to get rid of a H. pylori infection. 


If you still have symptoms after taking the medicines above, your GP may recommend that you take a prokinetic medicine. Domperidone and metoclopramide are both prokinetics. You can buy domperidone from your pharmacist without a prescription if you’re over 16. You take one to two 10mg tablets or 10 to 20ml liquid three to four times a day before a meal.

Your GP may prescribe metoclopramide. It comes as tablets, liquids or an injection. You will take one 10mg tablet or 10ml liquid three times a day.

Always read the patient information leaflet that comes with your medicine and if you have any questions, ask your GP or pharmacist for advice.

Special care

Use indigestion remedies with care if you have liver or kidney problems, if you're pregnant or breastfeeding, or if you're on a low-salt diet. Ask your GP or pharmacist for advice.

Side-effects of indigestion medicines

Side-effects are the unwanted, but mostly temporary effects you may get after taking a treatment.

Antacids that contain magnesium tend to have a laxative action, whereas those that contain aluminium may give you constipation. Magnesium carbonate can cause belching as carbon dioxide gas is released in your stomach.

Side-effects of H2-blockers and proton pump inhibitors can include:

  • diarrhoea or constipation
  • feeling sick or vomiting
  • wind
  • stomach ache
  • a headache
  • dizziness
  • tiredness

This section doesn’t include every possible side-effect of indigestion medicines. Please read the patient information leaflet that comes with your medicine for more information.

Interactions of indigestion medicines with other medicines

Check with your GP or pharmacist before you take any other medicines or herbal remedies at the same time as an indigestion treatment. Antacids, for example, can affect how your body absorbs other medicines.

Names of common indigestion medicines

Examples of the main types of indigestion medicines are shown in the table.

All medicines have a generic name. Many medicines also have one or more brand names. Generic names are in lower case, whereas brand names start with a capital letter.

Generic names Examples of common brand names
H2-blockers (over-the-counter)
ranitidine Zantac
famotidine Pepcid, Pepcid AC
H2-blockers (prescription-only)
cimetidine Tagamet
nizatidine Axid
Proton pump inhibitors (over-the-counter)
omeprazole Losec
Proton pump inhibitors (prescription-only)
esomeprazole Nexium
lansoprazole Zoton
pantoprazole Protium
rabeprazole Pariet
Examples of popular combination remedies
antacids and alginates Algicon
Andrews Antacid
Maalox Plus
Remegel Wind-eze


For answers to frequently asked questions on this topic, see FAQs.

For sources and links to further information, see Resources.

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  • This information was published by Bupa's Health Information Team and is based on reputable sources of medical evidence. It has been reviewed by appropriate medical or clinical professionals. Photos are only for illustrative purposes and do not reflect every presentation of a condition. The content is intended only for general information and does not replace the need for personal advice from a qualified health professional. For more details on how we produce our content and its sources, visit the about our health information page.

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  • Publication date: July 2011

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