Acid‐inhibitory effects of omeprazole and lansoprazole in Helicobacter pylori‐negative healthy subjects

Background: Omeprazole 20 mg once daily (o.d.) and lansoprazole 30 mg o.d. have similar acid‐inhibitory effects in healthy Helicobacter pylori‐positive subjects. However, little is known about the acid‐inhibitory effects of the o.d. and twice daily (b.d.) doses in H. pylori‐negative subjects. Aim: To compare the decrease in gastric acidity of omeprazole 20 mg (o.d. and b.d.) with lansoprazole 30 mg (o.d. and b.d.) in healthy H. pylori‐negative subjects on day 6–7 of dosing. Methods: A randomized, investigator‐blind, crossover study design was used. Intragastric pH was measured continuously with glass electrodes positioned in the gastric corpus. Sixteen H. pylori‐negative subjects, whose intragastric acidity fell below pH 4 for 70% of a 24‐h baseline period, were entered in the study. Results: Both dosing regimens of omeprazole and lansoprazole significantly increased median gastric pH and percentages of time above pH 4 during the entire 24‐h period, night‐ and daytime, compared to baseline. There were no significant differences in median gastric pH values or time above pH thresholds 3, 4 and 5 between the o.d. dosing regimens. During the night the percentage of time spent above pH 3 and 4 was significantly higher with omeprazole 20 mg b.d. than with lansoprazole 30 mg b.d. Conclusions: This comparative study demonstrates that daily doses of omeprazole 20 mg and lansoprazole 30 mg are equally effective in raising intragastric pH in H. pylori‐negative subjects on day 6 of dosing. During the night, omeprazole 20 mg b.d. provides superior gastric acid suppression compared to lansoprazole 30 mg b.d.