H2 blockers are medications that are used to treat conditions such as duodenal ulcers, gastric ulcers, and gastroesophageal reflux disease (GERD). Because they reduce the amount of acid in the stomach, they are also known as "acid reducers." They are taken by mouth, usually one to four times per day. A few of the most common side effects include abdominal pain (or stomach pain), constipation, and dizziness.
H2 blockers, also known as H2 receptor antagonists, are medications used to treat a variety of gastrointestinal conditions. They decrease the amount of acid produced by the stomach.
H2 blockers are available both over the counter and with a prescription. Prescription H2 blockers are used for the following conditions:
- Duodenal ulcers
- Gastric ulcers (stomach ulcers)
- Erosive esophagitis
- Pathological hypersecretory conditions (which occur when too much stomach acid is produced), such as Zollinger-Ellison syndrome or systemic mastocytosis.
Not all H2 blockers are approved for all of the conditions listed above. Over-the-counter H2 blockers are approved to treat less-serious conditions, including:
- Acid indigestion
- Sour stomach.
(Click H2 Blocker Uses for more information on these uses, as well as possible off-label uses for these medications.)
H2 blockers work by blocking a specific kind of histamine receptor. Histamine is a chemical released by that body that has several effects. In the stomach, histamine causes more acid to be produced. By blocking histamine in the stomach, H2 blockers reduce the amount of acid produced by the stomach. This is why H2 blockers are known as "acid reducers."