Description

Lansoprazole Sodium, Lyophilized Powder is a sterile, freeze-dried formulation of the proton pump inhibitor (PPI) drug, lansoprazole. The term “lyophilized powder” indicates that the drug has been converted into a stable, dry powder through a freeze-drying process. This formulation is specifically designed for intravenous (IV) administration.

Like other PPIs, lansoprazole is highly unstable in acidic environments. Administering it as a lyophilized powder that is reconstituted just before use prevents its degradation and allows for its safe and effective delivery directly into the bloodstream, bypassing the oral route.

Indications

This injectable form of lansoprazole is used in clinical settings where patients are unable to take oral medication. This often occurs in hospital settings for critically ill patients or those undergoing surgery. The main indications include:

• Short-term treatment of GERD: Used for patients with gastroesophageal reflux disease (GERD) with or without erosive esophagitis when oral therapy is not feasible.
• Prophylaxis and treatment of stress ulcers: In critically ill patients, it is used to prevent the development of stress-related mucosal bleeding and ulcers.
• Maintenance of hemostasis in peptic ulcer bleeding: It is used as an adjunct to therapeutic endoscopy to maintain a high gastric pH, which is crucial for clot stabilization and preventing re-bleeding from gastric or duodenal ulcers.
• Zollinger-Ellison syndrome: It can be used to manage this condition in patients who cannot take oral lansoprazole.

Mechanism of Action

The mechanism of action of lansoprazole sodium is the same as that of oral lansoprazole. It works by irreversibly inhibiting the final step of gastric acid production.

1. Prodrug Activation: Lansoprazole is a prodrug that is inactive in its original form. After being administered intravenously, it travels through the bloodstream and accumulates in the highly acidic secretory canaliculi of the gastric parietal cells.
2. Conversion to Active Form: In this acidic environment, lansoprazole undergoes a chemical transformation into its active sulfenamide form.

3. Irreversible Binding: This activated form then forms a permanent, irreversible covalent bond with the H+/K+-ATPase enzyme, which is also known as the “proton pump.” The proton pump is the enzyme responsible for pumping hydrogen ions (H+) into the stomach lumen, a key step in acid secretion.

4. Cessation of Acid Production: By irreversibly blocking the proton pump, lansoprazole effectively stops both basal (resting) and stimulated acid secretion. The acid-suppressing effect is sustained and powerful because the cell cannot resume acid production until new proton pumps are synthesized, a process that can take up to 24 hours.

This mechanism ensures that lansoprazole provides powerful and prolonged acid suppression, which is essential for the treatment and prevention of many acid-related diseases.