Sounds like 'ra-ni-ta-dine'

Easy-to-read medicine information about ranitidine – what it is, how to take ranitidine safely and possible side effects.

Type of medicine Also called
  • Belongs to a group of medicines called antihistamines   
  • Arrow-Ranitidine
  • Zantac
  • Ranitidine Relief® 
  • Peptisoothe®

What is ranitidine?

  • Ranitidine reduces the amount of acid produced in the stomach.
  • It is used to treat a number of stomach-related conditions caused by too much acid, such as indigestion, reflux, and ulcers.
  • It can also prevent ulcers from forming, or help the healing process where damage has already occurred.
  • Ranitidine may be used to prevent ulcers caused by medicines such as non-steroidal anti-inflammatory drugs (NSAIDs).
  • Examples of NSAIDs are diclofenac, ibuprofen, naproxen.


  • The usual dose of ranitidine is 150 mg twice a day or 300 mg once a day, at night.
  • For some people, 150 mg once a day is enough.
  • Duration (how long you need to take it) varies from one month to many years.
  • Always take your ranitidine exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much ranitidine to take, how often to take it, and any special instructions.

How to take ranitidine

  • Swallow your ranitidine tablet with a full glass of water.
  • Take ranitidine at the same times each day.
  • Ranitidine is not affected by food, so it can be taken before or after food.
  • If you forget to take your dose, take it as soon as you remember that day.
  • But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the amount.

Possible side effects

Like all medicines, ranitidine can cause unwanted side effects, although not everyone gets them. Often unwanted side effects improve as your body gets used to the new medicine.

Side effects What should I do?
  • Stomach upset 
  • Feeling sick (nausea)
  • Bloated
  • Gas in the tummy
  • Diarrhoea
  • Constipation
  • Headache
  • This is quite common when you first start taking ranitidine and usually goes way with time.
  • Tell your doctor if these continue.
  • Allergic reaction such as skin rash, itching, swelling of the lips, face, and mouth or difficulty breathing such as chest tightness, or wheezing
  • Tell your doctor immediately or ring HealthLine


  • Ranitidine may interact with a few medications and herbal supplements, so check with your doctor or pharmacist.
  • Ranitidine interacts with medications containing iron, calcium and magnesium. Take these products at least 1 hour before or 1 hour after taking a dose of ranitidine.

Learn more

Medsafe Consumer Information Sheet Ranitidine Relief

Credits: Sandra Ponen, Pharmacist. Reviewed By: Dr Janine Bycroft, GP, Health Navigator NZ