Reduction of gastric acid secretion by 10 mg and 30 mg omeprazole once daily.

The reduction in gastric acid secretion by 10 mg and 30 mg omeprazole was studied in 12 patients with ulcer disease in a randomized, double-blind, two-way balanced crossover study. A standardized pentagastrin test was performed before the study and 24 h after each treatment period of 6 days. Treatment was followed by a washout period of 7 days. Omeprazole, 30 mg/day, significantly reduced basal acid output (BAO) by 90% and pentagastrin-stimulated acid output (PAO) by 45% (p less than 0.01), whereas BAO and PAO were not significantly reduced by omeprazole, 10 mg/day.