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 effectively and to similar extents, but LAN has a faster effect on the relief of symptoms of gastroesophageal reflux. However, no strict comparison of the two proton pump inhibitors' effect on acid reflux and gastric acidity has been published. The aim of this study was to compare the effects of LAN and OME on gastroesophageal reflux with simultaneous measurements of gastric acidity in patients with established gastroesophageal reflux disease (GERD) and esophagitis.

Methods: Fourteen patients with endoscopically verified erosive esophagitis and with a pretreatment esophageal 24-h pH measurement showing acid reflux to the esophagus participated in the study. This was a double-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 20 mg OME daily, 24-h intraesophageal and intragastric acidity were measured with antimony electrodes connected to an ambulatory pH recording system.

Results: Ten of 14 patients completed the study. There were no differences in 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). However, the percentage of time with pH below 4 in the esophagus was significantly less during LAN treatment (1.92% +/- 2.29; mean +/- standard deviation) 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 treatment period (P = 0.031).

Conclusions: In this study lansoprazole and omeprazole had a comparable effect on gastric acidity in patients with established GERD with esophagitis. However, 30 mg lansoprazole daily reduced the acidity in the oesophagus and the number of refluxes more effectively than 20 mg omeprazole daily. This might indicate that proton pump inhibitors affect the esophageal clearance and/or influence the lower esophageal sphincter differently.