Pantoprazole versus omeprazole: influence on meal-stimulated gastric acid secretion

To determine the influence of recommended therapeutic doses of pantoprazole and omeprazole on meal-stimulated acid secretion.

In this double-blind, placebo-controlled, three-period crossover study, 12 healthy male volunteers received 40 mg pantoprazole od, 20 mg omeprazole od or placebo at 08:00 h for 5 days in a randomized order. Meal-stimulated acid secretion was determined by means of a homogenized test meal, and intragastric titration on day 1, 4-6 h, 8-10 h, 16-18 h, and 24-26 h, and on days 3 and 5, 4-6 h after oral drug administration.

On day 1 (4-6 h after oral drug administration), meal-stimulated acid secretion was decreased by 36% and 24% after administration of 40 mg pantoprazole or 20 mg omeprazole, respectively. After 3 and 5 days of dosing, the decreases were 88% and 85% with 40 mg pantoprazole, and 70% and 74% with 20 mg omeprazole. At all measuring points during the 5-day dosing periods, 40 mg pantoprazole proved superior to 20 mg omeprazole in inhibiting meal-stimulated gastric acid secretion. The differences were statistically significant for pantoprazole on day 1, 24-26 h after oral drug administration and on day 3 (P = 0.0425 and P = 0.0244, respectively). On day 1, only pantoprazole was significantly better than placebo (P = 0.0210, 4-6 h after dosing; P = 0.0093, 8-10 h after dosing and P = 0.0068, 16-18 h after dosing).

Pantoprazole 40 mg is significantly more effective than omeprazole 20 mg in inhibiting meal-stimulated acid secretion. In addition, pantoprazole exhibits a more rapid onset of action.