Lansoprazole is a proton-pump inhibitor (PPI) which inhibits the stomach's production of gastric acids. Lansoprazole is a proton-pump inhibitor (PPI) in the same pharmacologic class as omeprazole. Lansoprazole has been marketed for many years and is one of several PPIs available. Lansoprazole is a racemate 1:1-mixture of the enantiomers dexlansoprazole and levolansoprazole. Dexlansoprazole is an enantiomerically pure active ingredient of a commercial drug as a result of the 'enantiomeric shift'. Lansoprazole's plasma elimination half-life is not proportional to the duration of the drug's effects to the person. The mean plasma elimination half-life is 1.5 hours, and the effects of the drug last for over 24 hours after it has been used for 1 day or more. Lansoprazole interacts with several other drugs, either due to its own nature or as a proton pump inhibitor.