Initial potency of lansoprazole and omeprazole tablets on pentagastrin-stimulated gastric acid secretion - A placebo-controlled study in healthy volunteers

Abstract

Background: The new tablet formulation of omeprazole (Losec MUPS), is thought to have a stronger acid inhibition than the previously marketed capsules. Methods: The effects of the proton pump inhibitors lansoprazole and omeprazole tablets on pentagastrin-stimulated acid secretion were compared in Helicobacter pylori-negative healthy male volunteers (n = 12). The study was placebo-controlled, crossover matched and double-blind for lansoprazole (Agopton) and placebo, and single-blind for omeprazole tablets, Gastric acid response to sub-maximal pentagastrin-stimulation (0.6 μg · h/kg b.w.) was determined from 12.5 to 14.5 h after the first and second dose of the test drugs. Results: Lansoprazole 15 mg and 30 mg as well as omeprazole 20 mg tablets caused a marked decrease in gastric acid secretion, showing equipotency for 15 mg lansoprazole and 20 mg omeprazole tablets. Their efficacy, however, was lower than 30 mg lansoprazole. In addition, the inter-individual variation after omeprazole tablets was higher than following lansoprazole. Neither 7.5 mg lansoprazole nor 10 mg omeprazole tablets were clearly different from placebo on the first 2 days. The drugs were well-tolerated. No clinically relevant influence was found on either laboratory screen or cardiovascular parameters. Conclusion: Lansoprazole 15-30 mg shows a stronger acid inhibition and a lower inter-individual variability than the new omeprazole 20 mg tablets on days 1 and 2 of dosing.