2021 Mar 20. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–.
H2 receptor blockers, or H2 receptor antagonists (H2RAs), are a class of gastric acid-suppressing agents frequently used in various gastric conditions. They are FDA-approved for short-term use in treating uncomplicated gastroesophageal reflux disease (GERD), gastric or duodenal ulcers, gastric hypersecretion, and mild to infrequent heartburn or indigestion. H2RAs may also be used off-label for stress ulcer prophylaxis, esophagitis, gastritis, gastrointestinal hemorrhage, or urticaria. H2RAs are also sometimes included in a multidrug regimen for Helicobacter pylori. Although antacids are generally considered first-line agents for heartburn during pregnancy, H2RAs are pregnancy category B with no known teratogenic effects and may be used if needed. The overall therapeutic effectiveness of H2RAs greatly depends on the severity of gastric disease, dosage regimen, and duration of therapy. This activity describes the indications, contraindications, and use of H2 blockers and highlights the interprofessional team's role in promoting their safety.