THE EFFECTS OF OMEPRAZOLE 20 AND 40 MG TWICE-DAILY ON INTRAGASTRIC ACIDITY IN DUODENAL-ULCER PATIENTS

Background: The combination of omeprazole with amoxycillin or clarithr omycin is used as treatment against Helicobacter pylori. It seems like ly that the antibacterial activity of the antibiotic may be improved b y increasing gastric pH towards neutrality, and a twice daily regimen of omeprazole is probably needed. Aim: To assess the effects of twice daily administration of omeprazole 20 and 40 mg. Methods: Twelve duode nal ulcer patients in remission were randomized to receive in single-b lind fashion either placebo, omeprazole 20 mg or omeprazole 40 mg twic e daily (08.00 and 20.00 h). On the sixth day of dosing they underwent 24-h gastric pH-metry. Results: Omeprazole 20 and 40 mg b.d. produced marked decreases (P < 0.001) of 24-h gastric acidity (pH 5.4+/-0.9 an d pH 5.7+/-0.6, respectively, vs. a basal pH of 1.4+/-0.2) and kept ga stric pH at levels higher than 3.0 for almost 24 h. Gastric pH was kep t above 5.0 for about 18 h and above 6.0 for about 10 h, while the tim e spent above 7.0 did not exceed 3 h. There were no significant differ ences between the two omeprazole dosages at any pH threshold. Conclusi on: Omeprazole 20 mg b.d. is sufficient to render the gastric milieu a s anacidic as possible in duodenal patients.