Effect of omeprazole on gallbladder contraction in humans.

Background/aims: 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.

Methodology: 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.

Results: 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.

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