Lansoprazole belongs to a class of drugs termed proton-pump inhibitors (PPIs) and is prescribed for the treatment of duodenal and stomach ulcers, gastroesophageal reflux disease (GERD), and Zollinger-Ellison syndrome, a condition where a gastrin-producing tumor leads to severe reoccurring ulcers in the esophagus, stomach, and upper small intestine. Gastric acid, the juice secreted by the stomach that aids in digestion, is mainly composed of hydrochloric acid. If in excess, it has the ability to erode the gastric mucosal barrier, a protective layer that shields the stomach from erosion. Lansoprazole has the ability to decrease hydrochloric acid production by blocking the enzyme responsible for its production.
Lansoprazole became FDA approved for the treatment of heartburn and duodenal and stomach ulcers under the trade name Prevacid in 1995. It is currently manufactured through large-scale synthetic organic chemistry methods starting from simple, commercially available precursors.