Pantoprazole: Pantoprazole is a proton pump inhibitor (PPI) that suppresses the final step in gastric acid production by covalently binding to the (H+, K+)-ATPase enzyme system at the secretory
surface of the gastric parietal cell. This effect leads to inhibition of both basal and stimulated gastric
acid secretion, irrespective of the stimulus. The binding to the (H+, K+)-ATPase results in a duration
of antisecretory effect that persists longer than 24 hours for all doses tested (20 mg to 120 mg).
Levosulpiride: Levosulpiride selectively blocks DA2 receptors at the central level and at the
submucosal and myenteric plexus peripheral level, which interacts with the cholingeric, adrenergic
and peptidergic fibres to regulate the motility of gastrointestinal tract (GIT). Dopamine inhibits the
cholinergic neurons of the upper gastrointestinal tract and levosulpiride acts as a prokinetic agent
blocking the inhibition and hence permitting a sustained cholinergic induced contraction of smooth
muscle cell in the myenteric plexus. Via its antagonistic actions on the dopamine receptor in the CTZ,
it displays a strong antiemetic effect.
