Esomeprazole is a proton pump inhibitor (brand names sompraz, zoleri, nexium, lucen, esopral; axagon in italy, nexiam in belgium) developed and marketed by astrazeneca which is used in the treatment of dyspepsia, peptic ulcer disease (pud), gastroesophageal reflux disease (gord/gerd) and zollinger-ellison syndrome.

Omeprazole (INN) is a proton pump inhibitor used in the treatment of dyspepsia, peptic ulcer disease (pud), gastroesophageal reflux disease (gord/gerd) and zollinger-ellison syndrome. It was first marketed in the us in 1989 by astrazeneca under the brand names losec and prilosec, and is now also available from generic manufacturers under various brand names. Astrazeneca markets omeprazole as losec, antra, gastroloc, mopral, omepral, and prilosec.