Comparison of the effects of immediate-release omeprazole powder for oral suspension and pantoprazole delayed-release tablets on nocturnal acid breakthrough in patients with symptomatic gastro-oesophageal reflux disease

Background: Many patients treated with a proton-pump inhibitor for gastro-oesophageal reflux disease or erosive oesophagitis still have substantial night-time gastric acidity. A previous trial of a new immediate-release omeprazole oral suspension suggested that nocturnal gastric acidity could be more effectively controlled with a bedtime dose of immediate-release omeprazole than with a delayed-release proton-pump inhibitor administered before dinner or at bedtime. Aim: To compare the ability of immediate-release omeprazole with pantoprazole to control nocturnal gastric acidity, when they were dosed once daily and twice daily. Methods: Thirty-six patients with nocturnal gastro-oesophageal reflux disease symptoms received immediate-release omeprazole and pantoprazole in this open-label, randomized-crossover trial. Median gastric pH, the percentage of time with gastric pH > 4 and the percentage of patients with nocturnal acid breakthrough, were evaluated with 24-h pH monitoring. Results: Repeated once daily (bedtime) dosing with immediate-release omeprazole suspension produced significantly better nocturnal gastric acid control than repeated once daily (predinner) or twice daily (prebreakfast and bedtime) dosing with pantoprazole delayed-release tablets (median pH: 4.7 vs. 2.0 and 1.7; percentage of time pH > 4: 55 vs. 27 and 34; nocturnal acid breakthrough: 53 vs. 78 and 75). Twice daily dosing (prebreakfast and bedtime) with immediate-release omeprazole 20 and 40 mg achieved the best night-time control of gastric acidity. Repeated once daily bedtime dosing with immediate-release omeprazole 40 mg and twice daily dosing with pantoprazole 40 mg gave similar 24-h pH control. No safety issues were associated with either drug in this trial. Conclusions: Dosed once daily at bedtime, immediate-release omeprazole reduced nocturnal gastric acidity to a degree not observed with once daily dosing of delayed-release proton-pump inhibitors.