Metro Drug
Full Prescribing Info
Capsule: Each capsule contains: Omeprazole 20 mg & 40 mg.
Injection: Each vial contains Omeprazole sodium BP (equivalent to Omeprazole) 40mg.
Each ampoule contains: Sterile Water for Injection USP 10 mL.
Pharmacology: Pharmacodynamics: Omeprazole, a racemic mixture of two active enantiomers, reduces gastric acid secretion through a highly targeted mechanism of action. It is a specific inhibitor of the acid pump in the parietal cell. It is rapidly acting and provides control trough reversible inhibition of gastric acid secretion with once daily dosing. Ompeprazole is a weak base and is concentrated and converted to the active form in the highly acidic environment of the intracellular canaliculi within the parietal cell, where it inhibits the enzyme H+, K+ - ATPase - the acid pump. This effect on the final step of the gastric acid formation process is dose-dependent and provides for highly effective inhibition of both basal acid secretion and stimulated acid secretion, irrespective of stimulus.
Pharmacokinetics: Omeprazole is rapidly but variably absorbed following oral administration. Absorption is not affected by food. Omeprazole is acid-labile and pharmacokinetics may vary between the various formulations developed to improve oral bioavailability. The absorption of omeprazole also appears to be dose-dependent; increasing the dosage above 40 mg has been reported to increase the plasma concentrations in a non-linear fashion because of saturable first-pass hepatic metabolism. In addition, bioavailability is higher after long-term administration. Bioavailability of omeprazole may be increased in elderly patients, in some ethnic groups such as Chinese, and in patients with impaired hepatic function, but is not markedly affected in patients with renal impairment. On absorption, omeprazole is almost completely metabolized in the liver, primarily by the cytochrome P450 isoenzyme CYP2C19 to form hydroxyomeprazole, and to a small extent by CYP3A4 to form omeprazole sulfone. The metabolites are inactive and are excreted mostly in the urine and to a lesser extent in bile. The elimination half-life from plasma is reported to be about 0.5 to 3 hours. Omeprazole is highly bound (about 95%) to plasma proteins.
Omeprazole is used in conditions where inhibition of gastric acid secretion may be beneficial, including aspiration syndromes, dyspepsia, gastroesophageal reflux disease, peptic ulcer disease and the Zollinger-Ellison syndrome.
Injection: Benign gastric ulcer, gastric acid reduction, acid reflux disease, acid-related dyspepsia.
Dosage/Direction for Use
Capsule: Gastroesophageal reflux disease: 20 mg once daily for 4 weeks or as prescribed by the physician.
Dyspepsia: 10 to 20 mg daily for 2 to 4 weeks or as prescribed by the physician.
Peptic ulcer disease: 20 mg daily as single dose, or 40 mg in severe cases or as prescribed by the physician.
NSAID-associated ulceration: 20 mg daily or as prescribed by the physician.
Zollinger-Ellison syndrome: 60 mg once daily or as prescribed by the physician.
Acid aspiration prophylaxis during general anesthesia: 40 mg in the evening before surgery and further 40 mg two to six hours before the procedure or as prescribed by the physician.
Injection: Omeprazole inhibits secretion of gastric acid and is irreversibly blocking the enzyme system of hydrogen/potassium adenosine triphosphatase (H+/K+ATPase), the proton-pump of the gastric parietal cell.
Relief of Acid-Related Dyspepsia: Usual Dose: 10 or 20 mg daily orally for 2-4 weeks.
Gastroesophageal Reflux Disease: Usual Dose: 20 mg orally once daily for 4 weeks, followed by further 4-8 weeks if not fully healed.
Refractory Esophagitis: 40 mg daily may be used. Children weighing 10-20 kg: 10 mg daily orally; >20 kg: 20 mg daily.
Eradication of Helicobacter pylori in Peptic Ulceration: Omeprazole may be combined with antibacterials in dual triple therapy. Effective triple therapy regimens include omeprazole 20 mg twice daily combined with: Amoxicillin 500 mg and metronidazole 400 mg, both 3 times daily; clarithromycin 500 mg and metronidazole 400 mg or (tinidazole 500 mg both twice daily; or with amoxicillin 1 g and clarithromycin 500 mg both twice daily). These regimens are given for 1 week.
Dual therapy regimens eg, omeprazole 40 mg daily with either amoxicillin 750 mg to 1 g twice daily or clarithromycin 500 mg, 3 times daily, are less effective and must be given for 2 weeks. Omeprazole alone may be continued for a further 4-8 weeks.
Administration: Omeprazole may be given orally as the base or magnesium salt, or IV as the sodium salt.
The major clinical features were drowsiness, headache (possibly due to metabolite) and tachycardia.
Management is symptomatic and supportive treatment.
Patients known to be hypersensitive to omeprazole.
Special Precautions
Before giving omeprazole to patients with gastric ulcers the possibility of malignancy should be considered since these drugs may mask symptoms and delay diagnosis. It should also be used with caution in patients with hepatic impairment.
Use In Pregnancy & Lactation
Results from three prospective epidemiological studies indicate no adverse effects of omeprazole on pregnancy or on the health of the fetus/newborn child. Omeprazole can be used during pregnancy. Omeprazole is excreted in the breast milk but is not likely to influence the child when therapeutic doses are used.
Adverse Reactions
Adverse effects reported most frequently with omeprazole have been headache, diarrhea and skin rashes; they have sometimes been severe enough to require discontinuation of treatment. Other effects include pruritus, dizziness, fatigue, constipation, nausea and vomiting, flatulence, abdominal pain, arthralgia and myalgia, urticaria and dry mouth. Omeprazole may also increase the risk of gastrointestinal infections because of their acid suppressive effects.
Drug Interactions
Omeprazole and other proton-pump inhibitors are metabolized by the CYP450 system, primarily by isoenzyme CYP2C19 and may alter the metabolism of some other drugs metabolized by these enzymes. Omeprazole may prolong the elimination of diazepam, phenytoin and warfarin. Omeprazole and other proton-pump inhibitors reduce the absorption of drugs eg, ketoconazole and possibly itraconazole, whose absorption is dependent on an acid gastric pH. With voriconazole, the plasma concentration of both drugs may be increased and a reduced dose of omeprazole is recommended.
Capsule: Omeprazole may increase gastrointestinal pH, concurrent use with ampicillin esters, iron salts or ketoconazole may result in a reduction in absorption of these medications. Inhibition of the cytochrome P450 enzyme system by omeprazole, especially in high doses, may cause a decrease in the hepatic metabolism of anticoagulants (coumarin or indadione-derivative), diazepam or phenytoin, which may result in delayed elimination and increased blood concentrations, when these medications are used concurrently with omeprazole.
Concurrent use of omeprazole with bone marrow depressants may increase the leukopenic and/or thrombocytopenic effects of both medications. If concurrent use is required, close observation for toxic effects should be considered.
Store at temperatures not exceeding 30°C.
Injection: Store in a cool, dry place. Protect from light.
Shelf-Life: Vial: 24 months.
ATC Classification
A02BC01 - omeprazole ; Belongs to the class of proton pump inhibitors. Used in the treatment of peptic ulcer and gastro-oesophageal reflux disease (GERD).
Cap 20 mg (off-white spherical pellets encapsulated in empty gelatin size #2 with transparent pink cap and natural body) x 50's. 40 mg (off-white spherical pellets encapsulated in empty gelatin size #0 with orange cap and yellow body) x 24's. Powd for inj (vial + 10 mL amp diluent) 40 mg x 10 mL.
Register or sign in to continue
Asia's one-stop resource for medical news, clinical reference and education
Sign up for free
Already a member? Sign in