Esomeprazole sodium

Esomeprazole sodium
INN
Drug class
Routes of administration	Oral, intravenous
Pregnancy category
Bioavailability	50-90%
Metabolism	Hepatic (CYP2C19, CYP3A4)
Elimination half-life	1-1.5 hours
Excretion	Renal
Legal status
CAS Number	161796-78-7
PubChem	9579578
DrugBank	DB00736
ChemSpider	7853356
KEGG	D07911

Esomeprazole sodium is a proton pump inhibitor (PPI) used in the treatment of gastroesophageal reflux disease (GERD), peptic ulcer disease, and Zollinger-Ellison syndrome. It is the S-enantiomer of omeprazole, which means it is a specific optical isomer of the compound, providing a more targeted action in the body.

Pharmacology

Mechanism of Action

Esomeprazole sodium works by inhibiting the H+/K+ ATPase enzyme system found on the gastric parietal cells. This enzyme is often referred to as the "proton pump" of the stomach, and it is responsible for the secretion of gastric acid. By blocking this enzyme, esomeprazole effectively reduces the production of stomach acid.

Pharmacokinetics

Esomeprazole is absorbed rapidly after oral administration, with peak plasma concentrations occurring within 1 to 2 hours. The bioavailability of esomeprazole increases with repeated dosing, reaching approximately 90% after several days of administration. It is extensively metabolized in the liver by the cytochrome P450 system, primarily by CYP2C19 and CYP3A4 isoenzymes. The metabolites are excreted in the urine.

Clinical Uses

Gastroesophageal Reflux Disease (GERD)

Esomeprazole is commonly prescribed for the treatment of GERD, a condition characterized by the backward flow of stomach acid into the esophagus, causing heartburn and potential damage to the esophageal lining.

Peptic Ulcer Disease

In patients with peptic ulcer disease, esomeprazole helps to heal ulcers by reducing gastric acid secretion, thus allowing the ulcerated tissue to recover.

Zollinger-Ellison Syndrome

This rare condition involves the formation of gastrin-secreting tumors, leading to excessive gastric acid production. Esomeprazole is used to manage the acid hypersecretion associated with this syndrome.

Adverse Effects

Common side effects of esomeprazole include headache, diarrhea, nausea, flatulence, abdominal pain, constipation, and dry mouth. Long-term use of PPIs, including esomeprazole, has been associated with an increased risk of osteoporosis-related fractures, Clostridium difficile infection, and hypomagnesemia.

Drug Interactions

Esomeprazole can interact with other medications metabolized by the cytochrome P450 system. It may affect the absorption of drugs that require an acidic environment for optimal absorption, such as ketoconazole and iron salts. Additionally, esomeprazole may increase the serum levels of drugs such as diazepam, warfarin, and phenytoin.

Dosage and Administration

Esomeprazole is available in both oral and intravenous formulations. The typical oral dose for GERD is 20 to 40 mg once daily. For intravenous administration, the dose is usually 20 to 40 mg once daily, depending on the condition being treated.

Conclusion

Esomeprazole sodium is a widely used proton pump inhibitor with a well-established role in the management of acid-related disorders. Its efficacy in reducing gastric acid secretion makes it a valuable therapeutic option for conditions such as GERD, peptic ulcer disease, and Zollinger-Ellison syndrome.