Lansoprazole and omeprazole in the treatment of acid peptic disorders.

The pharmacology, pharmacokinetics, efficacy, safety, and dosage and administration of lansoprazole and omeprazole are reviewed. Lansoprazole and omeprazole are proton-pump inhibitors (PPIs). These agents bind covalently to hydrogen/potassium-exchanging adenosine triphosphatase in gastric parietal cells, rendering the molecule nonfunctional and inhibiting the secretion of gastric acid. The bioavailability of lansoprazole is 85%; that of omeprazole is 54%. Although lansoprazole and omeprazole have a plasma half-life of less than 2 hours, the duration of action is more than 24 hours. Clinical trials have shown lansoprazole and omeprazole to be effective in the treatment of duodenal ulcers, gastric ulcers, peptic ulcer disease involving Helicobacter pylori infection, recurrent ulcers, ulcers induced by nonsteroidal anti-inflammatory drugs, reflux esophagitis, Barrett esophagus, and Zollinger-Ellison syndrome. In many cases, these PPIs were more effective than histamine H2-receptor antagonists or worked when the latter failed. Lansoprazole and omeprazole have similar adverse-effect profiles and are well tolerated in both long- and short-term therapy. The dosage and duration of therapy vary with the condition being treated or the individual patient. Dosage adjustments should be considered only in the case of lansoprazole in patients with severe liver disease. Lansoprazole and omeprazole are highly specific in blocking a critical step in gastric acid production and have been found to be safe and effective in the treatment of many acid peptic disorders.