Omeprazole (Prilosec®) – Proton Pump Inhibitor


Omeprazole is a proton-pump inhibitor used in the treatment of gastroesophageal reflux and peptic ulcer disease.  It inhibits the p-type hydrogen-potassium ATPase responsible for parietal cell acid secretion into the gastric lumen, raising gastric pH and ameliorating reflux-related discomfort and erosive processes.  Despite its short half-life, the target binding kinetics of omeprazole facilitate extended acid control and once-daily dosing.

Omeprazole is also indicated for diseases involving acid hypersecretion (e.g., Zollinger-Ellison Syndrome, multiple endocrine neoplasia), active peptic ulcer disease, and Helicobacter pylori infection.  H. pylori treatment requires a multi-drug regimen involving two weeks of omeprazole and clarithromycin +/- amoxicillin therapy followed by omeprazole monotherapy.  Omeprazole is also used off-label to prevent peptic ulcers in patients taking NSAIDs.

The most common adverse effects associated with omeprazole are headache and GI distress, although acute interstitial nephritis, hypersensitivity reactions, and other organ dysfunction have also been reported.

In Plain English

Omeprazole blocks stomach cells from pumping acid into the digestive system.  This reduces discomfort from acid reflux, and helps ulcers to heal in a less acidic environment.

Clinical Considerations


Figure 1. Omeprazole clinical considerations at a glance (EE = erosive esophagitis)


Evidence Basis


Omeprazole In the News



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