Omeprazole is indicated for the treatment of duodenal ulcer, gastric ulcer and reflux oesophagitis.

Patients who are unable to take oral medication, e.g. in severely ill patients with either reflux oesophagitis, duodenal ulcer or gastric ulcer, omeprazole 40 mg IV bolus is recommended once daily for up to 5 days.

Administration: Omeprazole 40 mg i.v. injection should be administered intravenously only and should not be given by any other route.

Injection

For i.v. injection, reconstitute one sterile single dose vial of Omez^® injection with 10 mL of Sterile Water for Injection IP (without preservative) to make 10 mL solution containing 4 mg /mL of Omeprazole approximately.

The reconstituted solution of injection having Omez^® 4 mg/mL of Omeprazole approximately is stable for 8 hrs. when stored in original vial in a cool place.

The reconstituted solution of Omez^® injection should not be used if it contains visible particulate matter.

Infusion

For i.v. infusion, reconstitute one sterile single dose vial of Omez^® injection with 10 mL of Sterile Water for Injection IP (without preservative) to make 10 mL solution containing 4 mg/mL of Omeprazole approximately. Subsequently add 10 mL of reconstituted solution containing 4 mg/mL of Omeprazole approximately, to 90 mL of Sodium Chloride Injection IP (containing 0.9% w/v Sodium Chloride) or 90 mL of Dextrose Injection IP (containing 5% w/v of Dextrose) or 90 mL of Mannitol Injection IP (containing 5% w/v of Mannitol) to make 100 mL solution of 0.4 mg/mL of Omeprazole approximately. No other solution should be used for infusion. The resultant infusion should be given intravenously over a period of 20-30 minutes. The prepared infusion solution should be used within 3 hours of preparation and any unused portion should be discarded. The infusion solutions having omeprazole should not be refrigerated.

The diluted infusion solutions of Omez^® injection having 0.4 mg/mL of omeprazole approximately in infusion fluids are stable upto 18 hrs when stored in a cool place and protected from light. The diluted infusion solutions containing omeprazole sodium should not be used if they contain visible particulate matter.

Use in Children

The safety and effectiveness of omeprazole sodium injections in children have not yet been established.

Use in Patients with Impaired Liver Function

Dosage reduction may be required in patients with impaired liver function as omeprazole is extensively metabolized in the liver and its elimination rate is prolonged in such patients when compared to normal persons. The daily dose of 10-20 mg is recommended in patients with severe liver disease.

Use in Patients with Impaired Kidney Function

It is not necessary to adjust the dose of omeprazole in patients with renal insufficiency.

Use in Elderly Patients

It is not necessary to adjust the dose of omeprazole in elderly patients. However, a slight decrease in elimination rate and an increase in bioavailability are likely to occur in such patients.

• Patients who are hypersensitive to omeprazole, substituted benzimidazoles or other inactive ingredients of the formulation

• Omeprazole like other proton pump inhibitors (PPIs) should not be used concomitantly with nelfinavir.

In the presence of any alarm symptom (e.g. significant unintentional weight loss, recurrent vomiting, dysphagia, haematemesis or melena) and when gastric ulcer is suspected or present, malignancy should be excluded, as treatment may alleviate symptoms and delay diagnosis.

Co-administration of atazanavir with proton pump inhibitors is not recommended. If the combination of atazanavir with a proton pump inhibitor is judged unavoidable, close clinical monitoring (e.g virus load) is recommended in combination with an increase in the dose of atazanavir to 400 mg with 100 mg of ritonavir; omeprazole 20 mg should not be exceeded.

Omeprazole, as all acid-blocking medicines, may reduce the absorption of vitamin B₁₂ (cyanocobalamin) due to hypo- or achlorhydria. This should be considered in patients with reduced body stores or risk factors for reduced vitamin B₁₂ absorption on long-term therapy.

Omeprazole is a CYP2C19 inhibitor. When starting or ending treatment with omeprazole, the potential for interactions with drugs metabolised through CYP2C19 should be considered. An interaction is observed between clopidogrel and omeprazole. The clinical relevance of this interaction is uncertain. As a precaution, concomitant use of omeprazole and clopidogrel should be discouraged.

Treatment with proton pump inhibitors may lead to slightly increased risk of gastrointestinal infections such as Salmonella and Campylobacter.

Severe hypomagnesaemia has been reported in patients treated with proton pump inhibitors (PPIs) like omeprazole for at least three months, and in most cases for a year. Serious manifestations of hypomagnesaemia such as fatigue, tetany, delirium, convulsions, dizziness and ventricular arrhythmia can occur but they may begin insidiously and be overlooked. In most affected patients, hypomagnesaemia improved after magnesium replacement and discontinuation of the PPI.

For patients expected to be on prolonged treatment or who take PPIs with digoxin or drugs that may cause hypomagnesaemia (e.g. diuretics), healthcare professionals should consider measuring magnesium levels before starting PPI treatment and periodically during treatment.

Proton pump inhibitors, especially if used in high doses and over long durations (>1 year), may modestly increase the risk of hip, wrist and spine fracture, predominantly in the elderly or in presence of other recognised risk factors. Observational studies suggest that proton pump inhibitors may increase the overall risk of fracture by 10-40%. Some of this increase may be due to other risk factors. Patients at risk of osteoporosis should receive care according to current clinical guidelines and they should have an adequate intake of vitamin D and calcium.

Proton pump inhibitors are associated with very infrequent cases of subacute cutaneous lupus erythematosus (SCLE). If lesions occur, especially in sun-exposed areas of the skin, and if accompanied by arthralgia, the patient should seek medical help promptly and the health care professional should consider stopping omeprazole for intravenous. SCLE after previous treatment with a proton pump inhibitor may increase the risk of SCLE with other proton pump inhibitors.  

Interference with laboratory tests

Increased Chromogranin A (CgA) level may interfere with investigations for neuroendocrine tumours. To avoid this interference, omeprazole treatment should be stopped for at least 5 days before CgA measurements. If CgA and gastrin levels have not returned to reference range after initial measurement, measurements should be repeated 14 days after cessation of proton pump inhibitor treatment.  

As in all long-term treatments, especially when exceeding a treatment period of 1 year, patients should be kept under regular surveillance.