Products
Lansoprazole is commercially available in the form of capsules as meltable tablets (Agopton, generics). It has been approved in many countries since 1993.
Structure and properties
Lansoprazole (C16H14F3N3O2S, Mr = 369.4 g/mol) is a benzimidazole and pyridine derivative. It exists as a white to brownish-white, odorless, crystalline powder that is practically insoluble in water. Lansoprazole is a racemate. The pure enantiomer dexlansoprazole is also commercially available (dexilant).
Effects
Lansoprazole (ATC A02BC03) reduces gastric acid secretion by inhibiting the proton pump (H+/K+-ATPase) in the gastric vestibular cells irreversibly. It does not act locally in the lumen of the stomach but is absorbed in the intestine and travels to the vestibular cells via the systemic circulation. It is a prodrug and is converted from acid to its active form only in the canaliculi of the vestibular cells, where it binds covalently to the proton pump, inhibiting it. Lansoprazole is acid labile and must be administered in enteric-coated dosage forms. Lansoprazole has a short half-life of approximately 1.5 hours but has a long duration of action.
Indications
- Gastric and intestinal ulcers, gastritis.
- Acid regurgitation, stomach burning
- Helicobacter pylori eradication, in combination with antibiotics.
- As gastric protection during treatment with non-steroidal anti-inflammatory drugs.
- Gastroesophageal reflux, reflux esophagitis.
- Zollinger-Ellison syndrome
Dosage
According to the professional information. Medicines are usually taken once a day, for some indications twice a day and thirty minutes before meals.
Contraindications
- Hypersensitivity
- Combination with the HIV protease inhibitor atazanavir, because this greatly reduces atazanavir availability.
Full precautions can be found in the drug label.
Interactions
Lansoprazole is metabolized by CYP3A and CYP2C19 and is an inhibitor of P-glycoprotein. Corresponding interactions are possible. Other interactions may occur with anticoagulants, sucralfate, atazanavir, azole antifungals, and digoxin. Increasing gastric pH may affect the absorption of other drugs.
Adverse effects
The most common possible adverse effects include headache, dizziness, fatigue, rash, pruritus, digestive symptoms such as nausea, diarrhea, and constipation, and an increase in liver enzyme levels.
