RiteMED Omeprazole

Omeprazole (inj: sodium).

Each capsule contains: Omeprazole 20 mg.
Each vial contains: Omeprazole (as Sodium) 40 mg.

Injection: Pharmacology: Omeprazole belongs to a class of antisecretory compounds known as 'proton pump inhibitors' which are substituted benzimidazoles, that suppress gastric acid secretion by specific inhibition of the H⁺K⁺-ATPase enzymes system the 'acid (proton) pump' of the gastric parietal cell.
After intravenous administration of omeprazole, the onset of the antisecretory effects occurs within one hour with the maximum effect occurring within two hours. A single dose of 40 mg of omeprazole given intravenously has similar effect on intragastric acidity over a 24-hour period as repeated oral dosing with 20 mg once daily. Although the plasma half-life of omeprazole is very short, the antisecretory effect lasts longer due to prolonged binding to the parietal H⁺K⁺-ATPase enzyme.
Pharmacodynamics: Mechanisms of Action: Omeprazole is activated at an acidic pH to a sulphenamide derivative that binds irreversibly to H⁺K⁺-ATPase, an enzyme system found at the secretory surface of parietal cells. It thereby inhibits the final transport of hydrogen ions (via exchange with potassium ions) into the gastric lumen thus inhibiting acid secretion. Omeprazole inhibits both basal and stimulated acid secretion irrespective of the stimulus.
Pharmacokinetics: The apparent volume of distribution of omeprazole in healthy subjects and in patients with renal insufficiency is almost similar. The volume of distribution is slightly decreased in the elderly and in patients with hepatic insufficiency. The plasma protein binding of omeprazole is about 95%. The average half-life of the terminal phase of the plasma concentration-time curve following intravenous administration of omeprazole is approximately 40 minutes. Omeprazole is completely metabolized by the cytochrome P450 system, mainly in the liver. No metabolite has been found to have any effect on gastric acid secretion. Almost 80% of an intravenous dose of omeprazole is excreted as metabolites in the urine and the remainder is found in the faeces, primarily originating from biliary secretion.

Injection: Omeprazole is indicated for the treatment of duodenal ulcer, gastric ulcer, reflux oesophagitis and in control of acid secretion in pathological hypersecretory conditions, e.g., Zollinger-Ellison syndrome.

Injection: 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, can be given as IV bolus or infusion once daily for up to 5 days.
Zollinger-Ellison syndrome: Initially 60 mg IV daily, then adjust dose individually. For doses exceeding 60 mg daily, given as divided doses twice daily.
Administration: Administration by intravenous route only and not by any other route.
Use in Children: The safety and effectiveness of omeprazole sodium injection in children is not established.
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.
Use in Patients with Impaired Liver Function: Bioavailability and half-life of Omeprazole can increase in patients with hepatic impairment. UK licensed product information recommends that a maximum daily oral dose of 20 mg be used in these patients; a daily intravenous dose of 10 to 20 mg is considered sufficient.

Injection: There is no sufficient information available on deliberate overdosage with omeprazole. However, doses up to 400 mg have not resulted in severe symptoms. Therefore, treatment of overdosage should be symptomatic and supportive. In studies, intravenous doses up to 270 mg/day and up to 650 mg over a three-day period have been given without any dose related adverse effects.

Injection: Patients who are hypersensitive to omeprazole or any other ingredients of this formulation.
Pregnancy and lactation.

Injection: When gastric ulcer is suspected, the possibility of malignancy should be excluded before treatment with omeprazole is instituted, may alleviate symptoms and delay diagnosis. Decreased gastric acidity increases gastric counts of bacteria normally present in the gastrointestinal tract. Treatment with acid-reducing drugs may lead to a slightly increased risk of gastrointestinal infection such as Salmonella and Campylobacter.

Injection: Safety and efficacy of omeprazole is not established in pregnant and lactating women. Therefore, it should not be recommended in conditions of pregnancy and lactation.

Injection: The adverse effects reported most frequently with omeprazole have been gastrointestinal disturbances, in particular diarrhoea, constipation, abdominal pain, nausea, vomiting and flatulence. Skin rash, pruritus and urticaria have also been reported, usually resolving after discontinuation of treatment.
Central nervous system disorders reported include paresthesia, dizziness, lightheadedness and feeling faint, all of these usually resolved on cessation of therapy.
Somnolence, insomnia and vertigo have been reported rarely. Reversible mental confusion, agitation, depression and hallucinations have occurred predominantly in severely ill patients.
Other adverse events reported rarely include arthralgia and myalgia, blurred vision, taste disturbances, peripheral oedema, hyponatremia, blood disorders including agranulocytosis, leucopenia, thrombocytopenia, pancytopenia, anaphylactic shock, malaise, fever, bronchospasm, encephalopathy in patients with pre-existing severe liver disease, hepatitis with or without jaundice, rarely hepatic failure and interstitial nephritis which has resulted in acute renal failure.

Injection: The potential for metabolic interactions between omeprazole and other drugs is very limited. However, as omeprazole inhibits hepatic microsomal drug metabolism (cytochrome P450 system) or that are highly extracted by the liver may be decreased during concurrent use with omeprazole. This effect may result in delayed elimination, increased blood concentrations of diazepam, phenytoin and anticoagulants such as warfarin (monitoring of blood concentrations, or prothrombin time for anticoagulants is recommended as a guide to dosage since dosage adjustment may be necessary during omeprazole therapy).
Omeprazole, by increasing gastric pH, has the potential to affect the bioavailability of any medication for which absorption is pH-dependent and also omeprazole may prevent the degradation of acid-labile drugs. Therefore, concurrent use of itraconazole and ketoconazole with omeprazole may result in reduced absorption of these drugs.
Omeprazole has no influence on any other relevant isoforms of CYP, as shown by the lack of metabolic interaction with substrates for CYP1A2 (caffeine, phenacetin, theophylline), CYP2C9 (S-warfarin, piroxicam, diclofenac and naproxen), CYP2D6 (metoprolol, propranolol), CYP2E1 (ethanol) and CYP3A (cyclosporin, lidocaine, quinidine, estradiol, erythromycin, budesonide).

Injection: Injection: For I.V. injection, each single dose vial containing lyophilized powder of omeprazole 40 mg should be reconstituted with 10 mL of water for injection. The resulting concentration is 4 mg/mL of omeprazole. Omeprazole 40 mg should be given slowly (over a period of 5 minutes) as an intravenous injection.
Infusion: For I.V. infusion, the single dose vial should be dissolved in either 100 mL Sodium chloride injection (0.9% w/v) or 100 mL of glucose intravenous infusion (5% w/v). No other solution should be used for the infusion. The infusion should be given over a period of 20-30 minutes.
The reconstituted solution should be used within 3 hours of preparation and any unused portion should be discarded. The reconstituted solution should not be refrigerated.
Incompatibilities: Infusions with low pH should not be used for diluting omeprazole injection as fading & discoloration of solution can occur.

Injection: Store at temperatures not exceeding 25°C. Protect from light.

Antacids, Antireflux Agents & Antiulcerants

A02BC01 - omeprazole ; Belongs to the class of proton pump inhibitors. Used in the treatment of peptic ulcer and gastro-oesophageal reflux disease (GERD).

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