What is Esomeprazole (Nexium)?

Esomeprazole is a proton pump inhibitor (PPI), a drug that is used to reduce acid secretion in the stomach.

 

Other examples of PPIs include omeprazole, rabeprazole, pantoprazole and lansoprazole. These drugs are used to treat conditions such as peptic ulcer and gastroesophageal reflux disorder or GERD.

There are several different brand names for esomeprazole including Nexium, Essocam and Esmezol. Esomeprazole is the more active, S-isomer of the PPI omeprazole, which is marketed as Losec or Prilosec.

Indications for use

Some of the conditions, esomeprazole may be prescribed for include:

• Dyspepsia
• Peptic ulcer
• Gastroesophageal reflux disorder
• Zollinger-Ellison syndrome

Mechanism of action

Esomeprazole reduces acid secretion by inhibiting an enzyme called H+/K+ ATPase, which is present in gastric parietal cells. When this transporter protein is inhibited, gastric acid is not formed.

Dosing and pharmacokinetic considerations

Usually, a single oral dose of 20 to 40 mg per day is recommended and can lead to a peak plasma or blood concentration of 0.5 to1.0 mg/L within 1 to 4 hours of intake. After several days of use, this concentration can increase by half again. In some cases, intravenous administration may be required. A 30 minute intravenous infusion of a similar dose usually raises the peak blood concentration to around 1 to 3 mg/L. The drug is cleared rapidly, with inactive metabolites mainly passed in the urine.