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

Background: The new tablet formulation of omeprazole (Losec MUPS), is thoug ht to have a stronger acid inhibition than the previously marketed capsules . Methods: The effects of the proton pump inhibitors lansoprazole and omepraz ole tablets on pentagastrin-stimulated acid secretion were compared in Heli cobacter pylori-negative healthy male volunteers (n = 12). The study was pl acebo-controlled, crossover matched and double-blind for lansoprazole (Agop ton) and placebo, and single-blind for omeprazole tablets. Gastric acid res ponse to sub-maximal pentagastrin-stimulation (0.6 mu g . h/kg b.w.) was de termined from 12.5 to 14.5 h after the first and second dose of the test dr ugs. Results: Lansoprazole 15 mg and 30 mg as well as omeprazole 20 mg tablets c aused a marked decrease in gastric acid secretion, showing equipotency for 15 mg lansoprazole and 20 mg omeprazole tablets. Their efficacy, however, w as lower than 30 mg lansoprazole. In addition, the inter-individual variati on after omeprazole tablets was higher than following lansoprazole, Neither 7.5 mg lansoprazole nor 10 mg omeprazole tablets were clearly different fr om placebo on the first 2 days. The drugs were well-tolerated. No clinicall y relevant influence was found on either laboratory screen or cardiovascula r parameters, Conclusion: Lansoprazole 15-30 mg shows a stronger acid inhibition and a lo wer inter-individual variability than the new omeprazole 20 mg tablets on d ays 1 and 2 of dosing.