Lansoprazole: pharmacokinetics, pharmacodynamics and clinical uses.

Lansoprazole (Prevacid, TAP Pharmaceuticals, Inc.) is a substituted benzimidazole that inhibits gastric acid secretion. This agent is approved for the short-term treatment of erosive reflux oesophagitis, active gastric ulcer, active duodenal ulcer and the treatment of non-steroidal anti-inflammatory drug (NSAID)-induced gastric and duodenal ulcers. It is also approved for the long-term treatment of healed reflux oesophagitis, healed duodenal ulcer, the treatment of hypersecretory conditions such as Zollinger-Ellison syndrome and the eradication of Helicobacter pylori as a component of triple therapy with lansoprazole, clarithromycin and amoxicillin, or dual therapy with lansoprazole and amoxicillin. Its mechanism of action is to selectively inhibit the membrane enzyme H+/K+ ATPase in gastric parietal cells. In clinical trials, lansoprazole is more effective than placebo or histamine (H2)-receptor antagonists in the treatment of reflux oesophagitis. Lansoprazole administered at a dose of 30 mg daily produced faster relief of symptoms and superior healing rates in patients with gastric or duodenal ulcers or reflux oesophagitis than H2-receptor antagonists. A daily dose of 30 mg lansoprazole reduced epigastric pain faster than omeprazole 20 mg daily in patients with peptic ulcer disease but healing rates at 4 and 8 weeks were similar with both agents at these dosages. Lansoprazole was more effective than H2-receptor antagonists in patients with Zollinger-Ellison syndrome and produced similar treatment outcome to omeprazole. Lansoprazole in combination with clarithromycin and amoxicillin produced similar rates of eradication of H. pylori. In clinical trials, lansoprazole is well-tolerated and has a low frequency of side effects similar to that of H2-receptor antagonists or omeprazole.