Ranitidine to reduce stomach acid Zantac

Last updated by Peer reviewed by Sid Dajani
Last updated Meets Patient’s editorial guidelines

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Clinical author's note Michael Stewart 22/02/23: As a precautionary measure all ranitidine-containing products have been discontinued globally whilst the scientific investigation into its risks and benefits is ongoing. It is not known whether ranitidine products will be made available again in the future. If you have any concerns regarding your use of ranitidine please speak to your doctor or a pharmacist.

Clinical author's note Michael Stewart 21/11/2019: Since October 2019 a large number of ranitidine products have been recalled by their manufacturers. Pharmacies and other retailers have been told to remove these products from sale. The recalls are due to a risk of contamination with a potentially harmful chemical. There may be an ongoing shortage of ranitidine products as a consequence. If you have any concerns about the medicine you are taking you should speak with your pharmacist for advice.

Ranitidine reduces the amount of acid produced by your stomach.

Any side-effects are usually mild and do not last long.

Type of medicineH2-receptor antagonist
Used forTreatment of conditions caused by too much acid being produced in the stomach
Also calledZantac®
Available asTablets and oral liquid medicine

Ranitidine belongs to a group of medicines that reduce the amount of acid produced by the cells in the lining of the stomach. They are called 'histamine H2-receptor antagonists', but are commonly also called H2 blockers.

Ranitidine is helpful in the treatment of conditions caused by too much acid being produced in the stomach. These conditions include stomach ulcers (gastric ulcers), ulcers of the upper part of the intestine (duodenal ulcers), acid reflux or heartburn (reflux oesophagitis), and indigestion. Ranitidine is also prescribed to treat ulceration of the stomach which has been caused by non-steroidal anti-inflammatory drugs (NSAIDs).

Acid is produced naturally in your stomach to help you digest food. Excessive amounts of acid can irritate the lining of your stomach, causing inflammation, ulcers and other conditions. Ranitidine works by reducing the amount of acid produced by your stomach. This helps to relieve symptoms and assist the healing process where damage has already occurred.

Ranitidine is available on prescription. You can also buy short courses of ranitidine at retail outlets for symptoms such as heartburn, indigestion and hyperacidity in adults and in children over 16 years of age.

To make sure that this is the right treatment for you, before you start taking ranitidine it is important that you speak with a doctor or pharmacist:

  • If you are pregnant or breastfeeding.
  • If you have any of the following symptoms: difficulty swallowing, loss of blood, or weight loss, or if you are being sick.
  • If you have any problems with the way your kidneys work.
  • If you have a rare inherited blood disorder called porphyria.
  • If you have ever had an allergic reaction to a medicine.
  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.
  • Before you start this treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about ranitidine and will provide you with a full list of the side-effects which you may experience from taking it.
  • Take ranitidine exactly as your doctor tells you to, or as directed on the label if you have bought it. There are three different strengths of tablet available - 75 mg, 150 mg and 300 mg. Only the lower strength of tablet can be purchased. Ranitidine is taken once or twice a day.
  • You can take ranitidine either before or after meals.
  • If you forget to take a dose at your usual time, you can take it when you remember. However, if it is nearly time to take your next dose when you remember, leave out the missed dose and take your next dose when it is due. Do not take two doses together to make up for a forgotten dose.
  • A course of treatment can vary in length depending upon the reason why you are taking ranitidine. It may be just for a few days to relieve your symptoms, or for several weeks to help an ulcer heal. Keep any appointments that you have booked with your doctor so that your progress can be checked.
  • Some people say that certain foods make their symptoms worse. Foods and drinks that have been suspected of this include peppermint, tomatoes, chocolate, spicy foods, hot drinks, coffee, and alcoholic drinks. If it seems that a food is aggravating your symptoms, try avoiding it for a while to see if your symptoms improve. Also, try avoiding eating large meals, as these can make your symptoms worse too.
  • If you are overweight, this puts extra pressure on your stomach and encourages the symptoms of acid reflux. Losing some weight and eating a healthy balanced diet may help you.
  • Smoking increases the amount of acid produced by the stomach and may make your symptoms worse. If you are a smoker, speak with your doctor or pharmacist about how to quit.

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the ones associated with ranitidine, although these are generally mild and do not last long. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Ranitidine side-effects What can I do if I experience this?
Constipation or diarrhoea, tummy painThese should soon pass
Feeling sick (nausea)Stick to simple meals - avoid rich or spicy foods
Feeling dizzy, headacheThese should soon pass

If you experience any other symptoms which you think may be due to ranitidine, speak with your doctor or pharmacist for further advice.

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

If you buy any medicines, always check with a pharmacist that they are safe to take with your other medicines.

If you are having an operation or any dental treatment, tell the person carrying out the treatment which medicines you are taking.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

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