Effect of omeprazole on gallbladder contraction in humans

Omeprazole causes hypergastrinemia because of the effects of prolonged complete suppression of acid secretion and also gastrin has an excitatory effect on gallbladder contraction. Therefore, we investigated the meal-induced gallbladder emptying in healthy subjects receiving omeprazole and compared them to controls.

Twenty healthy volunteers participated in this study. Gallbladder volume was measured by ultrasonography. After basal measurement, the volunteers received saline intravenously (i.v.) 2 cc (no:10) or omeprazole 20 mg i.v. (no:10). After 15 min the gallbladder volume was scanned at 15 min intervals for 60 min for each of the subjects. At the end of the period, all the subjects received a standard test meal (ensure 250 cal/250 mL), after 1 hour the gallbladder volumes were rescanned at 15 min periods for 60 min.

Mean gallbladder volume in the omeprazole group was not significantly different during a 45 min period as compared to the baseline value. The residual gallbladder volume at the end of the 15th minute (43.9 +/- 5.6 mL), 30th minute (45.4 +/- 5.9 mL), 45th minute (40.5 +/- 6.1 mL) and 60th minute (40.5 +/- 6.1 mL) showed no significant differences in both the omeprazole group and the controls. Mean gallbladder volumes of both groups after meal intake were significantly lower during the 1-hour period as compared to the baseline value (P < 0.05). The mean volumes did not show any significant differences between the omeprazole group and the control subjects.

Omeprazole did not change the gallbladder volume during fasting and the postprandial period as compared to the control group.