LANSOPRAZOLE - A REAPPRAISAL OF ITS PHARMACODYNAMIC AND PHARMACOKINETIC PROPERTIES, AND ITS THERAPEUTIC EFFICACY IN ACID-RELATED DISORDERS

Lansoprazole is a benzimidazole derivative that effectively decreases gash ic acid secretion, regardless of the primary stimulus, via inhibi tion of gastric H+,K+-adenosine triphosphatase (ATPase). It provides e ffective symptom relief and healing of peptic ulcer and reflux oesopha gitis after 4 to 8 weeks of therapy and appears to prevent recurrence of lesions when administered as maintenance therapy. When administered at therapeutic dosages, lansoprazole produced higher healing rates th an ranitidine or famotidine in patients with duodenal and gastric ulce rs. Lansoprazole heals duodenal ulcers more rapidly than ranitidine or famotidine. Relief of ulcer symptoms in lansoprazole recipients is at least equivalent to, and tends to be more rapid than, that in patient s receiving histamine H-2-receptor antagonists. In comparisons with om eprazole 20 mg/day, lansoprazole 30 mg/day produced duodenal ulcer hea ling more rapidly and reduced ulcer pain to a greater extent at 2 week s, but overall healing rates were similar after 4 weeks of therapy. Ar therapeutic dosages, lansoprazole produces superior healing and sympt om relief of reflux oesophagitis in comparison with ranitidine, and it tends to relieve heartburn more effectively than omeprazole, although both agents produce equivalent healing. Healing of peptic ulcers or r eflux oesophagitis refractory to histamine H-2-receptor antagonists oc curs after 8 weeks in the majority of patients treated with lansoprazo le, and lansoprazole and omeprazole demonstrate similar efficacy in pa tients with refractory peptic ulcers. In patients with Zollinger-Ellis on syndrome, lansoprazole effectively controls mean basal gastric acid output. Lansoprazole is generally well tolerated in clinical trials. The incidence of adverse effects is similar to that of omeprazole, ran itidine and famotidine in comparative studies. Combination therapy wit h lansoprazole and antibacterial agents such as amoxicillin, tinidazol e, roxithromycin and/or metronidazole appears to eradicate Helicobacte r pylori in 22 to 80% of patients with this organism. Limited data als o suggest that lansoprazole may have superior activity against H. pylo ri in comparison with omeprazole, although the clinical relevance of t his preliminary finding requires further confirmation. Thus, lansopraz ole may be considered as an alternative to existing antisecretory agen ts available for the treatment of acid-related disorders, particularly because it may provide more rapid healing and relief of symptoms.