H2 Blockers (Acid Reducers) for Gastroesophageal Reflux Disease (GERD)

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H2 Blockers (Acid Reducers) for Gastroesophageal Reflux Disease (GERD)


Generic NameBrand Name

Some H2 blockers (also sometimes referred to as acid reducers or H2 receptor antagonists) are available in non-prescription and prescription forms. Prescription forms are stronger than the non-prescription forms.

H2 blockers are usually taken by mouth, although some can also be given as an injection. Two doses (morning and evening) are generally recommended to control both daytime and nighttime symptoms. Doctors sometimes recommend a single dose, taken at bedtime, for people who have difficulty remembering to take their medicines.

How It Works

H2 blockers reduce the production of stomach acid. This makes the stomach juices less acidic so that any stomach juice that gets into the esophagus is less irritating. This relieves symptoms and allows the esophagus to heal.

Why It Is Used

H2 blockers are used to treat the symptoms of gastroesophageal reflux disease (GERD). They may be prescribed for your symptoms without any diagnostic testing if your symptoms point to GERD.

  • H2 blockers may be used together with antacids.
  • Non-prescription H2 blockers may be used for up to 2 weeks for short-term symptom relief. But if you have been using non-prescription medicines to treat your symptoms for longer than 2 weeks, talk to your doctor. If you have GERD, the stomach acid could be causing damage to your esophagus. Your doctor can help you find the right treatment.
  • H2 blockers may be used on a long-term basis to relieve persistent GERD symptoms.

How Well It Works

All of the H2 blockers in this class are about equally effective.

H2 blockers heal the damage done to the esophagus by GERD (esophagitis) in about 5 out of 10 people.1

H2 blockers also work to help symptoms of GERD. But the number of people who take H2 blockers and who have no GERD symptoms is usually less than 5 out of 10 people. That means that of the people taking H2 blockers, more than 5 out of 10 still have some GERD symptoms.2

Side Effects

H2 blockers have been in use since the late 1960s. H2 blockers are well studied and are considered very safe.

Minimal side effects occur with use of H2 blockers. Side effects may include:

  • Headache.
  • Dizziness.
  • Diarrhea.
  • Constipation.
  • Nausea.
  • Vomiting.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Depending on how bad your symptoms are, medicines may need to be taken every day or only now and then when GERD symptoms occur. Long-term—often lifelong—drug treatment is usually needed for GERD symptoms that are more severe, because symptoms tend to return when drug treatment is stopped.

Treatment of inflammation in the esophagus (esophagitis) with H2 blockers usually lasts 8 to 12 weeks. If H2 blockers do not help relieve the symptoms, the doctor may recommend using a proton pump inhibitor (acid blocker) instead.

Lifestyle changes and antacids are usually tried first to treat pregnant women who have GERD. If you are pregnant and think you need something stronger, ranitidine and cimetidine are the H2 blockers that have been studied the most. They seem to be safe during pregnancy. It is always a good idea to talk to your doctor about what medicines are safe to use during pregnancy.

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  1. Moayyedi P, et al. (2007). Medical treatments in the short term management of reflux oesophagitis. Cochrane Database of Systematic Reviews (2).
  2. Kahrilas, PJ (2008). Gastroesophageal reflux disease. New England Journal of Medicine, 359(16): 1700–1707.


By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Primary Medical Reviewer Brian D. O'Brien, MD - Internal Medicine
Specialist Medical Reviewer Peter J. Kahrilas, MD - Gastroenterology
Last Revised May 18, 2010

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.