Omeprazole Sodium equivalent to Omeprazole 40 mg.
Pharmacology: Pharmacodynamics: 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 enzyme system, the 'acid (proton) pump' of the gastric parietal cell.
After intravenous administration of omeprazole, the onset of the antisecretory effect 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 (~ 50 minutes), the antisecretory effect lasts longer due to prolonged binding to the parietal H+ K+ ATPase enzyme. When the drug is discontinued, secretory activity returns gradually, over 3 to 5 days. The inhibitory effect of omeprazole on acid secretion is dose-related and increases with repeated once daily dosing, reaching a plateau after four days.
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.
Treatment of duodenal and gastric ulcer, NSAID - associated gastric acid and duodenal ulcers or erosions, Helicobacter pylori eradication in peptic ulcer disease, reflux oesophagitis, symptomatic gastro-oesophageal reflux disease, acid related dyspepsia and Zollinger - Ellison syndrome.
Adults only: Prophylaxis of acid aspiration: Omeprazole 40 mg given as an intravenous infusion to be completed one hour before surgery.
Treatment in patients where oral therapy is inappropriate e.g. in severely ill patients with either reflux oesophagitis, duodenal ulcer or gastric ulcer: Omeprazole 40 mg given as an intravenous infusion once daily is recommended for up to 5 days.
The i.v. infusion produces an immediate decrease in intragastric acidity and a mean decrease over 24 hours of approximately 90%.
Clinical experience in Zollinger-Ellison syndrome is limited.
Zollinger-Ellison syndrome: initially 60 mg IV daily, then adjust dosage individually. For doses exceeding 60 mg daily, give as divided doses twice daily.
Administration: Administration by intravenous route only and not by any other route 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.
Omeprazole powder for solution for infusion should only be dissolved in either 100 ml normal saline for infusion or 100 ml 5% dextrose for infusion. No other solutions for i.v. infusion should be used.
After reconstitution from a microbiological point of view, use immediately (i.e. within 3 hours) and any unused portion should be discarded.
The duration of administration should be 20-30 minutes.
Use in the elderly: Dosage adjustment is not necessary.
Use in children: There is limited experience of use in children.
Impaired renal function: Dose adjustment is not required in patients with impaired renal function.
Impaired hepatic function: As half-life is increased in patients with impaired hepatic function, the dose requires adjustment and a daily dose of 10 mg-20 mg may be sufficient.
Route of Administration: For I.V. injection or infusion after reconstitution.
Over Dosage: There is no sufficient information available on deliberate over dosage with omeprazole. However, doses up to 400 mg have not resulted in severe symptoms. Therefore, treatment of overdosage should be symptomatic and supportive. In clinical trails, 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.
Treatment: No specific antidote for omeprazole overdosage is known. Omeprazole is extensively protein bound and is, therefore, not readily dialyzable. In the event of overdosage, treatment should be symptomatic and supportive.
Known hypersensitivity to omeprazole or to any of the other constituents of the formulation. Omeprazole like other PPIs should not be administered with atazanavir.
When gastric ulcer is suspected, or an alarm symptom such as unintentional weight loss, vomiting, dysphagia, haematemesis occurs, the possibility of malignancy should be excluded as treatment may alleviate symptoms and delay diagnosis.
Well-conducted 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 breast milk. Influence, if any, on the child is unknown.
The adverse effects reported most frequently with omeprazole have been gastrointestinal disturbances, in particular diarrhoea, constipation, abdominal pain, nausea and vomiting and flatulence. Skin rash, pruritus and urticaria have also been reported, usually resolving after discontinuation of treatment.
Central nervous system disorders reported so far 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.
Rare: Hypersensitivity reactions, Myalgia, Anaphylactic reaction, Erythema multiforma.
Due to the decreased intragastric acidity, the absorption of ketoconazole or itraconazole may be reduced during omeprazole therapy as it is during treatment with other acid secretion inhibitors. As omeprazole is metabolised in the liver through cytochrome it can prolong the elimination of diazepam, phenytoin and warfarin. Monitoring of patients receiving phenytoin or warfarin is recommended and a reduction of phenytoin or warfarin dose may be necessary when Omeprazole is added to treatment. However, concomitant treatment with Omeprazole 20 mg orally daily, did not change the blood concentration of phenytoin in patients on continuous treatment with phenytoin. Similarly, concomitant treatment with Omeprazole 20 mg orally daily, did not change coagulation time in patients on continuous treatment with warfarin.
Plasma concentrations of omeprazole and clarithromycin are increased during concomitant oral administration. There is no interaction with metronidazole or amoxicillin. These antimicrobials are used together with omeprazole for eradication of Helicobacter pylori.
There is no evidence of an interaction with phenacetin, theophylline, caffeine, propranolol, metoprolol, ciclosporin, lidocaine, quinidine, estradiol, or antacids when Omeprazole is given orally. The absorption of Omeprazole given orally is not affected by alcohol or food.
There is no evidence of an interaction with piroxicam, diclofenac or naproxen, this is considered useful when patients are required to continue these treatments.
Simultaneous treatment with omeprazole and digoxin in healthy subjects led to a 10% increase in the bioavailability of digoxin as a consequence of the increased intragastric pH.
Interaction with other drugs also metabolised via the cytochrome P450 system cannot be excluded. Co-administration of omeprazole (40mg once daily) with atazanavir 300 mg/ritonavir 100mg to healthy volunteers resulted in a substantial reduction in atazanavir exposure (approximately 75% decrease in AUC, Cmax, and Cmin). Increasing the atazanavir dose to 400mg did not compensate for the impact of omeprazole on atazanavir exposure. PPIs including omeprazole should not be co-administered with atazanavir.
Concomitant administration of omeprazole and tacrolimus may increase the serum levels of tacrolimus.
Instruction for use and handling: Once opened and reconstituted the product may be stored for a maximum of 4 hours at 25°C. Any unused portion should be discarded.
Incompatibilities: The stability of omeprazole sodium depends on pH, in low pH fading of the solution can occur. Solutions prepared for i.v administration should not be refrigerated.
Store below 25 °C. Protect from light.
Shelf-Life: 24 months from the date of manufacture.
I.V Injection: 4 hours.
Infusion: 4 hours
A02BC01 - omeprazole ; Belongs to the class of proton pump inhibitors. Used in the treatment of peptic ulcer and gastro-oesophageal reflux disease (GERD).
Inj (lyo) for soln 40 mg (white lyophilized cake in vial) x 10 mL + 10 mL amp solvent.