Pepcid is a popular brand name for the drug famotidine, which is classified as an H2 receptor antagonist used to treat conditions like gastric ulcers, heartburn, and GERD. Though it is a widely recognized drug to treat acid reflux and digestive problems, there are several other synonyms for Pepcid, including Acid Control, Famotidine Tablets, Acid Reducer, and Heartburn Relief. Famotidine is also available over-the-counter under brand names like Pepcid AC, Fluxid, and Mylanta AR. Though they have different brand names, all the drugs contain famotidine as their active ingredient and work the same way to reduce acid levels in the stomach.