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CLINICAL PHARMACOLOGY:
Omeprazole belongs to a new class of antisecretory compounds, the substituted benzimidazoles, that do not exhibit anticholinergic or H2-histamine antagonistic properties but that suppress gastric acid secretion by specific inhibition of the H+/ K+ -ATPase enzymes system at the secretory surface of the gastric parietal cell. Because this enzyme system is regarded as the acid (proton) pump within the gastric mucosa, omeprazole has been characterized as a gastric acid pump inhibitor in that it blocks 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 the after rapid disappearance from plasma, omeprazole can be found within the gastric mucosa for a day or more.
INDICATIONS:
Omac-20 is indicated for short term treatment of duodenal ulcer, gastric ulcer, gastroescophageal; reflux disease and management of Zoilinger-Ellison syndrome.
CONTRAINDICATIONS:
There are no known contraindications to the use of Omeprazole.
PRECAUTIONS/WARNINGS:
Symptomatic response to therapy with omeprazole does not preclude the presence of gastric malignancy.
DRUG INTERACTIONS:
Omeprazole can prolong the eliminations of diazepam, warfarin and phenytoin, drug that are metabolized by oxidation in the liver. Monitoring of patients also receiving warfarin or phenytoin, is recommended and reduction of dose of phenytoin with propranolol or theophylline has been found, but interactions with other drugs also metabolised via the cytochrome P450 enzyme system cannot be excluded. No interaction with concomitantly administered antacids has been found.
PREGNANCY AND LACTATION:
As with all drugs, Omac-20 should not be given during pregnancy and lactation, unless its use is considered essential. Animal studies have not shown evidence of any hazard from the administration of omeprazole during pregnancy and lactation and there is no evidence of foetal toxicity or teratogenic effect.
CHILDREN:
There is no experience with omeprazole in children.
ELDERLY:
No dose adjustment is necessary in the elderly.
SIDE EFFECTS:
Omac is well tolerated. Nausea, Headache, Diarrhoea, Constipation and Flatulence are reported but occur rarely. These events are mild and transient and there has been no consistent relationship with treatment.
OVER DOSAGE:
There is no information available on the effects of over dosage in man and specific recommendations for treatment cannot be given. Single oral doses of upto 160 mg. have been well tolerated.
DOSAGE AND ADMINISTRATION:
Omac-20 should be taken before meals. Patients should be cautioned that the capsules should not be opened, chewed or crushed and should be swallowed whole.
Duodenal ulcer, gastric ulcers and reflux oesophagisits: The recommended dosage is one capsule of Omac-20 (20 mg.) once daily.
In patients with duodenal ulcers symptom relief is rapid and healing occurs within 2 weeks in most cases. For those patients who have not fully healed after the initial course, healing usually occurs during a further 2 weeks treatment period. In patients with gastric ulcers and reflux oesophagitis symptom relief is rapid and healing occurs within 4 weeks in most cases. For those patients who may have not fully healed after the initial course, healing usually occurs during a further 4 weeks treatment period.
In patients refractory to other treatment regimens, 2 capsules of Omac-20 (40 mg.) once daily has been used and healing achieved, usually within 4 weeks in patients with duodenal ulcers and within 8 weeks in patients with gastric ulcers or reflux oesophagitis.
Zoilinger-Ellison syndrome: The recommended initial dosage is 3 capsules of Omac-20 (60 mg.) once daily. The dosage should be adjusted individually and treatment continued as long as clinically indicated. All patients with severe disease and inadequate response to other therapies have been effectively controlled and more than 90% of patients maintained on the doses of 20-120 mg. daily. With doses above 80 mg. daily the dose should be divided and given twice daily.
IMPAIRED RENAL AND LIVER FUNCTION:
No doses adjustment is required in patients with impaired renal or liver function and in the elderly.
INSTRUCTIONS:
Capsule is not to be crushed or chewed. It is to be swallowed as whole along with water.
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