Rabeprazole Sodium and Domperidone Maleate

Rabeprazole is a PPI that suppresses gastric acid secretion by inhibiting the gastric H+K+ ATPase at the secretory surface of the gastric parietal cell. Because this enzyme is regarded as the acid (proton) pump within the parietal cell, rabeprazole has been characterized as a gastric proton pump inhibitor. Rabeprazole blocks the final step of gastric acid secretion. Onset of action is 1 hour. Duration 24 hours. Absorption Oral bioavailability is about 52% and peak plasma concentrations are reached about 3.5 hr after oral admin. The median inhibitory effect of rabeprazole on 24 hour gastric acidity is 88% of maximal after the first dose.
Domperidone is a dopamine antagonist with anti-emetic properties domperidone does not readily cross the blood-brain barrier. Its anti-emetic effect may be due to a combination of peripheral (gastrokinetic) effects and antagonism of dopamine receptors in the chemoreceptor trigger zone, which lies outside the blood-brain barrier in the area postrema. Studies in man have shown oral domperidone to increase lower esophaegeal pressure, improve antroduodenal motility and accelerate gastric emptying. There is no effect on gastric secretion