What to Know About H2 Receptor Blockers for GERD

Medically Reviewed by Poonam Sachdev on December 01, 2021

H2 receptor blockers are drugs that are used to treat gastroesophageal reflux disease (GERD) and peptic ulcers. This drug is effective, cheap, and safe for relieving heartburn. It is available by prescription and over-the-counter, though the over-the-counter H2 receptor blockers have a lower dose of active ingredients and are used to treat mild heartburn.

What Is GERD?

Gastroesophageal reflux disease (GERD) is a digestive condition characterized by partially digested foods, acidic stomach juices, and fluid coming up into the esophagus from the stomach. It may affect individuals of any age, including infants. 

Heartburn occurs when you get a burning sensation in your chest due to stomach acid going up into the throat. It develops into GERD if it goes on for some time.

A common risk factor for getting GERD is underlying asthma. An asthmatic attack may cause relaxation of the lower esophageal sphincter. This relaxation lets the stomach contents flow back up the esophagus. The effect of some asthma treatment drugs like theophylline has been found to worsen GERD symptoms. GERD may also worsen asthma symptoms due to the irritation it causes the lungs and airways.

What Are the Symptoms of GERD?

A common GERD symptom is an acidic taste in your mouth when reflux happens.

Other GERD symptoms may include:

  • Severe sore throat
  • Painful or difficult swallowing
  • Severe cough
  • Acid regurgitation
  • Excess saliva
  • Gum inflammation
  • Bad breath
  • Laryngitis
  • Chest pain

What Other Conditions Are Treated with H2 Receptor Blockers?

Another name for H2 receptor blockers is H2 receptor antagonists (H2RAs). These drugs are FDA-approved to treat other gastric conditions like:

  • Gastric hypersecretion
  • Gastric and duodenal ulcers
  • Esophagitis
  • Gastrointestinal hemorrhage
  • Urticaria
  • Gastritis
  • Indigestion
  • Stress ulcers

How Do H2 Receptor Blockers Work?

H2 receptor blocker medications work by reducing the amount of stomach acid released by glands in the lining of your stomach and thereby reducing symptoms of heartburn. A decrease in acidity also allows peptic ulcers to heal.

H2 receptor antagonist medications are absorbed quickly by the stomach. The drugs may get to peak blood levels in about one to three hours.

Some prescription H2 receptor blocker medications include:

Are There Side Effects of H2 Receptor Blockers?

There are few reported cases of H2 receptor blocker side effects. When side effects occur, they are usually minor. Some of them include:

  • Fatigue
  • Diarrhea
  • Headache
  • Constipation
  • Muscle pains
  • Drowsiness

Can You Overdose on H2 Receptor Blockers?

It is possible to overdose on H2 receptor antagonist medications if you take more than the prescribed amount. Some of the symptoms of an H2 receptor blocker overdose are:

  • Confusion
  • Diarrhea
  • Nausea
  • Vomiting
  • Drowsiness
  • Abnormal heartbeat (too fast or too slow)
  • Difficult breathing
  • Sweating
  • Dilated pupils
  • Low blood pressure
  • Slurred speech
  • Flushing

You should call a doctor immediately after noticing the symptoms of an overdose. Avoid inducing vomiting unless you are advised to do so by a health care professional or poison control. It might also be helpful to carry the container of the swallowed drug to the hospital if possible.

Consider taking down the following information before calling for help:

  • The name of the affected individual
  • Weight
  • The severity of the condition 
  • The name of the medication (include ingredients and strength if possible)
  • Time of swallowing
  • The amount swallowed

Overdose Management

After getting to the emergency room, the doctor may start by taking vital signs like temperature, blood pressure, breathing rate, and pulse. They may also go on to take tests like chest x-rays, blood tests, urine analysis, and ECG (electrocardiogram).

Treatment may include:

  • Breathing support
  • Intravenous (IV) fluids
  • Activated charcoal
  • Laxatives
  • Other symptom management medications

What Other Drugs Are Used to Treat GERD?

Proton pump inhibitors are the preferred prescription medications for gastrointestinal reflux disease. They work by preventing the parietal cells of the stomach from producing acid. Proton pump inhibitors available in the U.S.  include:

  • Omeprazole (Prilosec, Prilosec OTC, Zegerid)
  • Dexlansoprazole (Dexilant)
  • Pantoprazole (Protonix)
  • Rabeprazole (Aciphex)
  • Lansoprazole (Prevacid)
  • Esomeprazole (Nexium)

Researchers found that proton pump inhibitors are more efficient in treating acid reflux than H2 receptor blockers. That is because proton pump inhibitors are better at preventing the production of acid in the stomach.

Show Sources


American Academy of Allergy, Asthma & Immunology: “Gastroesophageal Reflux Disease.”

Bethesda (MD). Histamine Type-2 Receptor Antagonists (H2 Blockers), National Institute of Diabetes and Digestive and Kidney Diseases, 2018.

International Foundation for Gastrointestinal Disorders: “H2 Blockers,”“Proton Pump Inhibitors (PPIs).”

Japanese journal of clinical medicine: "[Comparison between histamine H2-blocker and proton pump inhibitor on the effects of initial treatment in reflux esophagitis]"

Nugent, C., Falkson, S. Terrell J, StatPearls, "H2 Blockers," StatPearls Publishing, 2021.

University of Florida Health: “H2 receptor antagonists overdose.”

© 2020 WebMD, LLC. All rights reserved. View privacy policy and trust info