If you have heartburn or gastroesophageal reflux disease (GERD), a common class of drug that can help is the histamine 2 (H2) blocker. These type of medications reduce the amount of acid the stomach produces by blocking histamine, an organic compound that tells your stomach to churn out acid. There are prescription and non-prescription H2 blockers. The choices you can find over the counter include Tagamet-HB, Pepcid-AC, Axid AR, and Zantac 75.
While H2 blockers haven't been around as long as antacids, they have been available since the 1970s. H2 blockers are stronger than antacids and can fight acid reflux for 8 to 12 hours.
You can use them for up to two weeks for short-term relief of heartburn. Side effects may include headache, dizziness, diarrhea, constipation, nausea, and vomiting, but they are considered safe. H2 blockers relieve mild GERD symptoms in about 60% of people.