DESCRIPTION
Rabeprazole -Rabeprazole is an antiulcer drug in the class of proton pump inhibitors. It is a prodrug – in the acid environment of the parietal cells it turns into active sulphenamide form. Rabeprazole inhibits the H+, K+ATPase of the coating gastric cells and dose-dependent oppresses basal and stimulated gastric acid secretion.Itopride-Itopride is a dopamine D2 antagonist with acetylcholinesterase inhibitory actions.
CATEGORIES
Rabeprazole -Enzyme Inhibitors,Anti-Ulcer Agents.Itopride-GIT Regulators & Anti-Inflammatories.
CHEMICAL FORMULA
Rabeprazole -C18H21N3O3S.Itopride-C20H26N2O4.
COMPOSITION
Rabeprazole 20mg + Itopride 150mg
INDICATION
Rabeprazole -For the treatment of acid-reflux disorders (GERD), peptic ulcer disease, H. pylori eradication, and prevention of gastroinetestinal bleeds with NSAID use.Itopride-Investigated for use/treatment in gastrointestinal diseases and disorders (miscellaneous).
PHARMACODYNAMICS
Rabeprazole -Rabeprazole prevents the production of acid in the stomach. It reduces symptoms and prevents injury to the esophagus or stomach in patients with gastroesophageal reflux disease (GERD) or ulcers. Rabeprazole is also useful in conditions that produce too much stomach acid such as Zollinger-Ellison syndrome. Rabeprazole may also be used with antibiotics to get rid of bacteria that are associated with some ulcers. Rabeprazole is a selective and irreversible proton pump inhibitor, suppresses gastric acid secretion by specific inhibition of the H+, K+ -ATPase, which is found at the secretory surface of parietal cells. In doing so, it inhibits the final transport of hydrogen ions (via exchange with potassium ions) into the gastric lumen.
MECHANISM
Rabeprazole -Rabeprazole belongs to a class of antisecretory compounds (substituted benzimidazole proton-pump inhibitors) that do not exhibit anticholinergic or histamine H2-receptor antagonist properties, but suppress gastric acid secretion by inhibiting the gastric H+/K+ATPase (hydrogen-potassium adenosine triphosphatase) 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. In gastric parietal cells, rabeprazole is protonated, accumulates, and is transformed to an active sulfenamide. When studied in vitro, rabeprazole is chemically activated at pH 1.2 with a half-life of 78 seconds.Itopride-Itopride has anticholinesterase (AchE) activity as well as dopamine D2 receptor antagonistic activity. It is well established that M3 receptors exist on the smooth muscle layer throughout the gut and acetylcholine (ACh) released from enteric nerve endings stimulates the contraction of smooth muscle through M3 receptors. The enzyme AChE hydrolyses the released ACh, inactivates it and thus inhibits the gastric motility leading to various digestive disorders. Besides ACh, dopamine is present in significant amounts in the gastrointestinal tract and has several inhibitory effects on gastrointestinal motility, including reduction of lower esophageal sphincter and intragastric pressure. These effects appear to result from suppression of ACh release from the myenteric motor neurons and are mediated by the D2 subtype of dopamine receptors. Itopride, by virtue of its dopamine D2 receptor antagonism, removes the inhibitory effects on Ach release. It also inhibits the enzyme AchE which prevents the degradation of ACh. The net effect is an increase in ACh concentration, which in turn, promotes gastric motility, increases the lower esophageal sphincter pressure, accelerates gastric emptying and improves gastro-duodenal coordination. This dual mode of action of Itopride is unique and different from the actions of other prokinetic agents available in the market.
ABSORPTION
Rabeprazole -Absolute bioavailability is approximately 52%.
METABOLISM
Rabeprazole -Hepatic.Itopride-Flavin-containing monooxygenase (FMO) is involved in N-oxygenation, the major metabolic pathway of itopride (PMID: 10997945).
ELIMINATION
Rabeprazole -Following a single 20 mg oral dose of 14C-labeled rabeprazole, approximately 90% of the drug was eliminated in the urine, primarily as thioether carboxylic acid; its glucuronide, and mercapturic acid metabolites.
HALF LIFE
Rabeprazole -1-2 hours (in plasma).
FOOD INTERACTIONS
Rabeprazole -Take without regard to meals. Take without regard to meals. Food may slow absorption rate but extent of absorption is not affected.
SIDE EFFECTS
Rabeprazole -Headache. Loose stools (diarrhea). Gas. Hip, spine, or wrist fractures may rarely happen.Itopride-Rash, diarrhoea, constipation, abdominal pain, headache, sleeping disorders, dizziness, galactorrhea, gynecomastia.