H2 blockers are acid-reducing medications that are typically used to help relieve the symptoms of acid reflux or treat gastroesophageal reflux disease, according to MedlinePlus. They are also used to treat peptic or stomach ulcers.
H2 blockers work by blocking the signals that cause the stomach to produce acid, explains Healthline. Parietal cells, which are located in the stomach lining, produce stomach acid, and many foods and liquids stimulate these cells. H2 blockers come in liquid, capsule and tablet forms and are often taken with or before meals. They take between 30 to 90 minutes to begin working, and the benefits often last several hours, explains MedlinePlus.
Many H2 blockers are available over-the-counter, including Pepcid AC, Zantac 75, Tagamet and Axid AR. Stronger versions of these medications are available by prescription, notes Healthline. H2 blockers may be used together with antacids, and patients can use them on a long-term basis to relieve persistent acid reflux or treat inflammation of the esophagus, according to WebMD. Patients are advised to consult their doctors if their symptoms do not improve or if they begin to experience side effects. Side effects of H2 blockers are rare but may include dizziness, headache, rashes or diarrhea, according to MedlinePlus.