BACKGROUND

Intragastric acid suppression is the most direct measure of the pharmacodynamic efficacy of proton pump inhibitors, which are the most effective drugs for acid-related diseases.

AIM

To compare the effectiveness of once and twice daily dosing of lansoprazole and esomeprazole in controlling intragastric acidity (target gastric pH > 4.0) over a 24-hour period.

METHODS

In an open-label, two-way crossover study, 45 Helicobacter pylori-negative patients with gastro-oesophageal reflux disease were randomized to receive one of two regimens: 30 mg lansoprazole or esomeprazole 40 mg once daily. Intragastric pH was assessed by 24-hour pH monitoring on day 5 of each regimen. Dosing was increased to twice daily and pH was reassessed on day 10. Following a 14-day washout, patients were crossed over to the other medication and the dosage regimens and pH assessments were repeated.

RESULTS

Data were analysed from 35 patients who completed all scheduled assessments and had 24-hour monitoring for each end-point. Mean time pH > 4.0 and mean 24-hour pH were highest for esomeprazole 40 mg twice daily, followed by lansoprazole 30 mg twice daily, esomeprazole 40 mg once daily and lansoprazole 30 mg once daily. Esomeprazole 40 mg twice daily provided superior control of intragastric pH compared with either once or twice daily dosing of lansoprazole and once daily dosing of esomeprazole (P < 0.01). Esomeprazole 40 mg once daily was comparable with lansoprazole 30 mg twice daily and both were superior to lansoprazole 30 mg once daily (P < 0.01).

CONCLUSIONS

Response to acid suppression treatment depends on the treatment selected. Esomeprazole 40 mg twice daily provided better control of intragastric pH than all other regimens evaluated. Esomeprazole 40 mg daily, however, was comparable with lansoprazole 30 mg twice daily and superior to lansoprazole 30 mg once daily.