Influence of acid suppressants on gastric emptying: Cross-over analysis in healthy volunteers

Background: Gastric emptying plays an important role in gastroesophageal reflux disease. Acid suppressants such as H-2 receptor antagonists and/or proton pump inhibitors are often used in patients with gastroesophageal reflux disease. However, it remains controversial whether H-2 receptor antagonists and proton pump inhibitors delay or accelerate gastric emptying. Here, the influence of acid suppressants on gastric emptying was evaluated via a cross-over study using the [C-13]-labeled acetate breath test. Methods: Twenty normal male subjects without gastroesophageal reflux disease symptoms were enrolled. Gastric emptying was investigated five times in every subject by the [C-13]-labeled acetate breath test with oral administration of the vehicle, domperidone, and three acid suppressants: ranitidine, famotidine and rabeprazole. Gastric emptying was estimated by the values of Tmax-calc, T-1/2 and %dose/2 h calculated from the (CO2)-C-13 breath excretion curve. Results: Using the Tmax-calc values, rabeprazole, ranitidine and famotidine did not influence gastric emptying time in comparison with vehicle administration. Using the T-1/2 and %dose/2 h values, rabeprazole tended to delay gastric emptying. Domperidone produced a statistically significant acceleration of gastric emptying for all three variables (P < 0.05). Conclusion: Oral dosage of the H-2 receptor antagonists, ranitidine and famotidine, has no significant effect on gastric emptying. However, rabeprazole may delay gastric emptying more strongly than H-2 receptor antagonists.