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. Domperidone – A specific blocker of dopamine receptors. It speeds gastrointestinal peristalsis, causes prolactin release, and is used as antiemetic and tool in the study of dopaminergic mechanisms.
CATEGORIES
Rabeprazole – Enzyme Inhibitors,Anti-Ulcer Agents. Domperidone – Antiemetics, GIT Regulators & Anti-Inflammatories .
CHEMICAL FORMULA
Rabeprazole – C18H21N3O3S ,Domperidone – C22H24ClN5O2.
COMPOSITION
Rabeprazole 20 MG+Domperidone 30 MG
INDICATION
Rabeprazole – For the treatment of acid-reflux disorders (GERD), peptic ulcer disease, H. pylori eradication, and prevention of gastroinetestinal bleeds with NSAID use. Domperidone – For management of dyspepsia, heartburn, epigastric pain, nausea, and vomiting.
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. Domperidone – Domperidone is a specific blocker of dopamine receptors. It speeds gastrointestinal peristalsis, causes prolactin release, and is used as antiemetic and tool in the study of dopaminergic mechanisms.
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. Domperidone – Domperidone acts as a gastrointestinal emptying (delayed) adjunct and peristaltic stimulant. The gastroprokinetic properties of domperidone are related to its peripheral dopamine receptor blocking properties. Domperidone facilitates gastric emptying and decreases small bowel transit time by increasing esophageal and gastric peristalsis and by lowering esophageal sphincter pressure. Antiemetic: The antiemetic properties of domperidone are related to its dopamine receptor blocking activity at both the chemoreceptor trigger zone and at the gastric level. It has strong affinities for the D2 and D3 dopamine receptors, which are found in the chemoreceptor trigger zone, located just outside the blood brain barrier, which – among others – regulates nausea and vomiting .
ABSORPTION
Rabeprazole – Absolute bioavailability is approximately 52%. Domperidone – Fast.
METABOLISM
Rabeprazole – Hepatic .Domperidone – Hepatic and intestinal (first-pass) .
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. Domperidone – Breast milk, renal.
HALF LIFE
Rabeprazole – 1-2 hours (in plasma).Domperidone – 7 hours.
TOXICITY
Domperidone – Side effects include galactorrhea, gynecomastia, or menstrual irregularities.
FOOD INTERACTIONS
avoid alcohol
SIDE EFFECTS
Rabeprazole – Headache. Loose stools (diarrhea). Gas. Hip, spine, or wrist fractures may rarely happen.Domperidone -Headache. Dry mouth. Good mouth care, sucking hard, sugar-free candy, or chewing sugar-free gum may help. See a dentist often .