A non-sedating histamine H2-receptor antagonist that inhibits stomach acid production. It is used to help prevent and treat heartburn, indigestion, upset stomach, and other symptoms of gastroesophageal reflux disease (GERD). Famotidine Tablet is a non-sedating histamine H2-receptor antagonist that inhibits stomach acid production. It is used to help prevent and treat heartburn, indigestion, upset stomach, and other symptoms of gastroesophageal reflux disease (GERD).