Rabeprazole Sodium 20 mg
Each enteric-coated Tablet contains
Rabeprazole sodium 20mg
Colour: Iron oxide yellow
The active ingredient in RABEFAST enteric Tablets is rabeprazole sodium, a substituted benzimidazole that inhibits gastric acid secretion. Rabeprazole sodium is known chemically as 2-[[[4-(3- methoxypropoxy)-3-methyl-2-pyridinyl].methyl]sulfinyl] -1 H-benzimidazole sodium salt. It has an empirical formula of C18H20N3NaO3S and a molecular weight of 381.43. Rabeprazole sodium is a white to slightly yellowish-white solid, it is very soluble in water and methanol, freely soluble in ethanol, chloroform and ethyl acetate and insoluble in either and n-hexane. The stability of rabeprazole sodium is a function of pH; it is rapidly degraded in acid media, and is more stable under alkaline conditions.
Mode of Action
Rabeprozole sodium belongs to the class of antisecretory compounds, the substituted benzimidazoles, that do not exhibit anticholinergic or H2 histamine antagonist properties, but suppress gastric acid secretion by the specific inhibition of the, H+/K +- ATPase enzyme at the secretory surface of the gastric Rabeprazole sodiumaI cell. This enzyme system is regarded as the acid (proton) pump, and therefore rabeprazole sodium is classified as a gastric proton-pump inhibitor blocking the final step of acid production. This effect is dose-related and leads to inhibition of both basal and stimulated acid secretion irrespective of the stimulus. Animal studies indicate that after administration,
rabeprazole sodium rapidly disappears from both the plasma and gastric mucosa.
After oral administration of a 20mg dose of rabeprazole sodium the onset of the anti-secretory effect occurs within one hour with the maximum effect occurring within two to four hours. Inhibition of basal and food stimulated acid secretion 23 hours after the first dose of rabeprazole sodium are 69% and 82% respectively and the duration of inhibition lasts up to 48 hours. This duration of pharmacodyaction is much longer than the pharmacokinétic half life (approximately one hour) would predict. This effect is probably due to the prolonged binding to the Rabeprozole sodiumol H+/K+- ATPase enzyme. The inhibitory effect of rabeprazole sodium on acid secretion increases slightly with repeated once- daily dosing, achieving steady state inhibition after three days. When the drug is discontinued, secretory activity normalises over 2 to 3 days.
Serum Gastrin Effects
In clinical studies patients were treated once daily with 20mg rabeprazole sodium, for up to 24 months duration. Serum gastrin levels increased during the first 2 to 8 weeks reflecting the inhibitory effects on acid secretion. Gastrin values returned to pretreatment levels, usually within 1 to 2 weeks after discontinuation of therapy.
This is acid-labiIe, and is therefore administered orally as an enteric-coated (gastro-resistant) tablet formulation. Absorption of rabeprazole sodium therefore begins only after the tablet leaves the stomach. Absorption is rapid, with peak plasma levels of rabeprozole sodium occurring approximately 3.5 hours after a 20mg dose. Peak plasma concentrations (Cmax) of rabeprazole sodium and AUC are linear over the dose range of 10mg to 40mg. Absolute bioavailability of an oral 20mg dose (compared to intravenous administration) is about 52% due in large part to pre-systemic metabolism. Additionally the bioavailability does not appear to increase with repeat administration. In healthy subjects the plasma haf-life is approximately one hour (range 0.7 to 1.5 hours), and the total body clearance is estimated to be 283 + 98 mL/min. In patients with chronic hepatic disease, the AUC doubled compared to healthy volunteers, reflecting a decreased first-pass effect, and the plasma half-life increased 2-3 sold.
Rabeprazole sodium is approximately 97% bound to human plasma proteins.
Rabeprazole Sodium tablets are indicated for the treatment of:
•Active duodenal ulcer
•Active benign gastric ulcer
•Symptomatic erosive or ulcerative gastro-oesophageal reflux disease (GERD).
•H. Pylori-positive duodenal ulcers, as part of the eradication programme with appropriate antibiotics.
•Maintenance treatment of healed erosive or ulcerative GERD. Efficacy has not been demonstrated for periods exceeding 12 months.
RABEPRAZOLE SODIUM is contra-indicated in:
•Patients with known hypersensitivity to rabeprazole sodium, substituted benzimidazoles or to any excipient used in the formulation.
•Pregnancy and lactation.
Rabeprazole is metabolized by the cytochrome P450 (CYP450) drug metabolizing enzyme system. Studies in healthy subjects have shown that rabeprazole does not have clinically significant interactions with other drugs metabolized by the CYP450 system, such as warfarin and theophylline given as single oral doses, diazepam as a single intravenous dose, and phenytoin given as a single intravenous dose (with supplemental oral dosing). Steady state interactions of rabeprazole and other drugs metabolized by this enzyme system have not been studied in patients.
The most common adverse effects were headache, diarrhoea and nausea. Other adverse effects were rhinitis, abdominal pain, asthenia, flotulence, pharyngitis, vomiting, non-specific pain/back pain, dizziness, flu syndrome, infection, cough, constipation and insomnia. Further less frequent adverse effects were rash, myalgia, chest pain, dry mouth, dysoepsia, nervousness, somnolence, bronchitis, sinusitis, chills, eruction, leg cramps, urinary tract infection, arthralgia and fever.
In isolated cases, anorexia, gastritis, weight gain, depression, pruritus, vision or taste disturbances, stomati, sweating and leucocytosis have been observed.
Increased hepatic enzymes have been observed in 2% of patients.
Dosage and Administration:
Active Duodenal Ulcer and Active Benign Gastric Ulcer:
20mg to be taken once daily in the morning.
Most patients with active duodenal ulcer heal within four weeks. However 2% of patients may require an additional four weeks of therapy to achieve healing.
Some patients with active duodenal ulcer may respond to one 10mg tablet to be taken once daily in the morning.
Most patients with active benign gastric ulcer heal within six weeks. However 9% of patients, may require an additional six weeks of therapy to achieve healing.
Erosive or Ulcerative Gastro-Oesophageal Reflux Disease (GERD)
20mg to be taken once daily for four to eight weeks. Gastro-Oesophageal Reflux Long-term Management (GERD Maintenance)
For long term management up to 12 months, a maintenance dose of Rabeprazole sodium 20mg once daily can be used.
Eradication of H. PyIcri
Rabeprazole sodium is indicated for H. Pylori-positive duodenal ulcers, as part of the eradication programme with appropriate antibiotics.
Rabeprazole sodium tablets should be taken in the morning, before eating; and although neither the time of day nor food intake was shown to have any effect on rabeprazole sodium activity, this regimen will facilitate treatment compliance.
Patients should be cautioned that the Rabeprazole sodium tablets should not be chewed or crushed, but should be swallowed whole.
Rabeprazole sodium tablets should be used within 3 months of first opening the aluminum pouch container.
Renal and hepatic impairment
No dosage adjustment is necessary for patients with renal or hepatic impairment.
Caution is however advised when Rabeprazole sodium is first initiated in patients with severe hepatic dysfunction; see ‘Side Effects and Special Precautions’.
Rabeprazole sodium is not recommended for use in children, as there is no experience of its use in this group.
No specific antidote is known. Rabeprazole sodium is extensively protein bound and is, therefore, not readily dialysable. Treatment should be supportive and symptomatic.
Storage: Store at temperature below 25oC.
Protect from light and moisture
Keep out of reach of children
RABEFAST is available in Alu. / Alu. Blister 10xl 0 Tablets or 3×10 Tablets.
Manufactured in India By
PULSE PHARMACEUTICALS PVT., LTD
Khasra No. 400, 407, 409 Karondi, Roorkee – 247 667,
BIOFEM PHARMACEUTICALS (Nig) LTD.