Comparison of the effect of lansoprazole and omeprazole on intragastric acidity and gastroesophageal reflux in patients with gastroesophageal reflux disease

Background: Lansoprazole (LAN) and omeprazole (OME) heal esophagitis effect ively and to similar extents, but LAN has a faster effect on the relief of symptoms of gastroesophageal reflux. However, no strict comparison of the t wo proton pump inhibitors' effect on acid reflux and gastric acidity has be en published. The aim of this study was to compare the effects of LAN and O ME on gastroesophageal reflux with simultaneous measurements of gastric aci dity in patients with established gastroesophageal reflux disease (GERD) an d esophagitis. Methods: Fourteen patients with endoscopically verified eros ive esophagitis and with a pretreatment esophageal 24-h pH measurement show ing acid reflux to the esophagus participated in the study. This was a doub le-blind, randomized study with crossover design. Before (day 0) and on the last day (day 5) of each treatment period with encapsulated 30 mg LAN or 2 0 mg OME daily, 24-h intraesophageal and intragastric acidity were measured with antimony electrodes connected to an ambulatory pH recording system. R esults: Ten of 14 patients completed the study. There were no differences i n intragastric or intraesophageal acidity or the number of reflux episodes on day 0 between the two treatments. Both LAN and OME treatments increased the median and nocturnal intragastric pH and decreased the 24-h area under the time curve for intragastric acidity significantly and to about the same extent (79% and 69% acid inhibition by LAN and OME, respectively) (NS). Ho wever, the percentage of time with pH below 4 in the esophagus was signific antly less during LAN treatment (1.92% +/- 2.29; mean +/- standard deviatio n) than during OME treatment (4.76% +/- 2.88%) on day 5 (P = 0.002). There were also significantly fewer reflux episodes >5 min during treatment with LAN (1.00 +/- 1.33) than with OME (2.90 +/- 2.42) at the end of the treatme nt period (P = 0.031). Conclusions: In this study lansoprazole and omeprazo le had a comparable effect on gastric acidity in patients with established GERD with esophagitis. However, 30 mg lansoprazole daily reduced the acidit y in the oesophagus and the number of refluxes more effectively than 20 mg omeprazole daily. This might indicate that proton pump inhibitors affect th e esophageal clearance and/or influence the lower esophageal sphincter diff erently.