Medications for the prevention and treatment of the progression of gastroesophageal reflux disease to adenocarcinoma, and more specifically to medications that operate in accordance with a new mechanistic understanding of the sequence of changes whereby gastroesophageal reflux disease progresses to adenocarcinoma are provided. The medications for the prevention and treatment of reflux-induced adenocarcinoma are based on (1) recognizing cardiac mucosa as an abnormal epithelium that should be a target of treatment, (2) preventing cardiac mucosa from progressing to intestinal metaplasia (Barrett esophagus), and (3) promoting the conversion of cardiac mucosa to oxyntocardiac mucosa, which is recognized by the invention as being a benign epithelium that does not progress to intestinal metaplasia (Barrett esophagus) and adenocarcinoma. In patients who already have intestinal metaplasia at the time of detection, the medications for prevention and treatment require a preliminary step whereby the intestinal metaplasia is reverted to cardiac mucosa before it can be induced to convert to the benign oxyntocardiac mucosa.