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


    Generic Name Brand Name
    cimetidine Tagamet
    famotidine Pepcid
    nizatidine Axid
    ranitidine Zantac

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

    H2 blockers are usually taken by mouth, although some can also be given as an injection. Two doses (morning and evening) are typically 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.
    • Nonprescription H2 blockers may be used for up to 2 weeks for short-term symptom relief. But if you have been using nonprescription 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 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.1

    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.

    Side Effects

    All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

    Here are some important things to think about:

    • Usually the benefits of the medicine are more important than any minor side effects.
    • Side effects may go away after you take the medicine for a while.
    • If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

    Call911or other emergency services right away if you have:

    Common side effects of this medicine include:

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

    What To Think About

    Antacids and H2 blockers should not be taken within 1 hour of each other, because the antacid will cause the H2 blocker to take effect more slowly.

    Taking medicine

    Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

    There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

    Advice for women

    If you are pregnant, breast-feeding, or planning to get pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant, breast-feeding, or planning to get pregnant.


    Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

    Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.


    1. Kahrilas, PJ (2008). Gastroesophageal reflux disease. New England Journal of Medicine, 359(16): 1700-1707.

    ByHealthwise Staff
    Primary Medical ReviewerAdam Husney, MD - Family Medicine
    Specialist Medical ReviewerPeter J. Kahrilas, MD - Gastroenterology

    Current as ofNovember 14, 2014

    WebMD Medical Reference from Healthwise

    Last Updated: November 14, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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