EZZ - oh - MEPP -ruh -zole
Most drug molecules are chiral, which means they exist in two mirror image forms (designated "R" and "S" for reasons we needn't discuss here).
Usually there's no significant difference between the R- and S- form, but sometimes there is. When Prilosecâ„¢ (omeprazole) went off-patent, AstraZeneca isolated the S- form of the molecule and marketed it (in magnesium salt form) as Nexiumâ„¢.
Thus, S-omeprazole, or esomeprazole.