Esomeprazole · Nexium

What is Esomeprazole?

Esomeprazole is the S-isomer of omeprazole and a proton pump inhibitor. It is converted in the acidic compartment of gastric parietal cells to an active sulfenamide that forms covalent disulfide bonds with H+/K+ ATPase, blocking the final step of gastric acid secretion. It is studied in erosive esophagitis and chronic hepatitis B.

Summary written with AI from the sources listed at the end of this page.

At a glance

Also known as

Nexium

Drug type

Small molecule

Targets

H+/K+ ATPase (gastric proton pump) (ATP4A)

Mechanism

Inhibitor of H+/K+ ATPase (gastric proton pump) (ATP4A)

Pathways

gastric acid secretion

Therapy area

Gastroenterology, Infectious disease

Developer

Astrazeneca

In trials of

ARVN, ASMB, IQV

FDA status

Approved as Nexium (February 20, 2001), NDA021153 · FDA label

✅ FDA-approved uses

• Erosive esophagitis
• Gastric ulcer associated with NSAID use
• Helicobacter pylori infection
• Zollinger-Ellison syndrome

From the indications section of the FDA label (version of Dec 19, 2025). Read the full label for the exact wording, limitations and safety information.

🧪 Clinical trials

Trials of the companies BioRadar tracks, from ClinicalTrials.gov, most advanced phase first.

Conditions studied

Erosive EsophagitisChronic Hepatitis BHealthy

Other drugs acting on ATP4A

Sources

• FDA label (DailyMed)
• FDA label Nexium (2025-12-19), indications
• NCI Thesaurus
• NCI Thesaurus
• ClinicalTrials.gov NCT06275841

Updated Oct 11, 2026.