Omeprazole


Full Prescribing Info
Dosage/Direction for Use

Oral
Peptic ulcer
Adult: 20 mg or 40 mg once daily. Treatment duration: 4 weeks (duodenal ulcer); 8 weeks (gastric ulcer). Maintenance: 10-20 mg once daily, may increase up to 40 mg according to response.
Hepatic impairment:
10-20 mg daily.

Oral
NSAID-associated ulceration
Adult: 20 mg once daily for up to 8 weeks. Maintenance: 20 mg once daily.
Hepatic impairment:
10-20 mg daily.

Oral
Eradication of H. pylori associated with peptic ulcer disease
Adult: 20 mg bid for 1 week in combination with clarithromycin and with either amoxicillin or metronidazole. Alternatively, 40 mg once daily for 1 week in combination with amoxicillin and metronidazole.
Child: >4 years
15-30 kg: 10 mg bid. 31->40 kg: 20 mg bid. All doses are given in combination with amoxicillin and clarithromycin for 1 week.
Hepatic impairment: 10-20 mg daily.

Oral
Gastro-oesophageal reflux disease

Adult: 20 mg once daily for 4-8 weeks. For severe case: 40 mg once daily for 8 weeks. Maintenance: 10 mg once daily, may increase to 20-40 mg once daily if necessary.
Child: ≥1 year
weighing 10-20 kg: 10 mg once daily, increased to 20 mg once daily if necessary. ≥2 years weighing >20 kg: 20 mg once daily, increased to 40 mg once daily if necessary. Treatment duration: 4-8 weeks.
Hepatic impairment: 10-20 mg daily.

Oral
Zollinger-Ellison syndrome
Adult: Initially, 60 mg daily, adjust as required. Usual dose: 20-120 mg daily. Doses >80 mg should be given in 2 divided doses.
Hepatic impairment:
10-20 mg daily.

Intravenous
Gastro-oesophageal reflux disease
Adult: 40 mg once daily given via infusion over 20-30 minutes until oral administration is possible.
Hepatic impairment:
10-20 mg daily.
Reconstitution: IV infusion: Reconstitute with 100 mL of dextrose 5% or NaCl 0.9% inj.

Intravenous
Gastric and duodenal ulcers

Adult: 40 mg once daily given via infusion over 20-30 minutes until oral administration is possible.
Hepatic impairment:
10-20 mg daily.
Reconstitution: IV infusion: Reconstitute with 100 mL of dextrose 5% or NaCl 0.9% inj.

Intravenous
NSAID-associated ulceration

Adult: 40 mg once daily given via infusion over 20-30 minutes until oral administration is possible.
Hepatic impairment:
10-20 mg daily.
Reconstitution: IV infusion: Reconstitute with 100 mL of dextrose 5% or NaCl 0.9% inj.

Intravenous
Eradication of H. pylori associated with peptic ulcer disease

Adult: 40 mg once daily given via infusion over 20-30 minutes until oral administration is possible.
Hepatic impairment:
10-20 mg daily.
Reconstitution: IV infusion: Reconstitute with 100 mL of dextrose 5% or NaCl 0.9% inj.

Intravenous
Zollinger-Ellison syndrome

Adult: Initially, 60 mg daily via infusion over 20-30 minutes, adjust dose according to response. Daily doses >60 mg should be given in 2 divided doses.
Hepatic impairment:
10-20 mg daily.
Reconstitution: IV infusion: Reconstitute with 100 mL of dextrose 5% or NaCl 0.9% inj.

Special Populations: Pharmacogenomics CYP2C19 is the main enzyme responsible in omeprazole metabolism. CYP2C19 polymorphism test can be considered to identify individuals who may require dose adjustment or experience treatment failure. The incidence of CYP2C19 poor metaboliser is markedly higher in Asians. 15 to 20% of Asians have reduced or absent CYP2C19 enzyme activity. Ultrarapid metabolisers (carriers of 2 increased function alleles *17/*17) Eradication of H. pylori: Increase dose by 100-200%. Monitor for risks of therapeutic failure.
Administration
Delayed-release cap: Should be taken on an empty stomach. Take at least 1 hr before meals. Swallow whole, do not chew/crush. For patients w/ difficulty swallowing, cap may be carefully opened & entire contents sprinkled in a spoonful of applesauce. Swallow drug/food mixt w/o chewing immediately after prep. Drug/food mixt should not be stored for future use.
Powd for oral susp: Should be taken on an empty stomach. Take on an empty stomach at least 1 hr before a meal.
MUPS tab: May be taken with or without food.
Cap: Should be taken with food. Take immediately before a meal.
Contraindications
Concomitant use with nelfinavir.
Special Precautions
Patient with reduced body store or risk factors for reduced vitamin B12 absorption; risk of osteoporosis. Hepatic impairment. Children, elderly. Pregnancy and lactation. CYP2C19 ultrarapid metabolisers. Monitoring Parameters Rule out gastric malignancy prior to initiation of treatment. Monitor Mg concentrations prior to initiation and periodically thereafter.
Adverse Reactions
Significant: Hypomagnasaemia, cutaneous lupus erythematosus, SLE, osteoporosis-related fractures, fundic gland polyp, carcinoma, Clostridium) difficile-associated diarrhoea, interstitial nephritis, Vitamin B12 deficiency (long-term therapy), gastrointestinal infection (e.g. salmonella, Campylobacter). Gastrointestinal disorders: Nausea, vomiting, diarrhoea, constipation, flatulence, abdominal pain. General disorders and administration site conditions: Weakness, malaise. Hepatobiliary disorders: Increased liver enzymes. Immune system disorders: Urticaria. Metabolism and nutrition disorders: Peripheral oedema. Musculoskeletal and connective tissue disorders: Back pain. Nervous system disorders: Headache, dizziness, somnolence, paraesthesia, vertigo. Psychiatric disorders: Insomnia. Respiratory, thoracic and mediastinal disorders: Cough. Skin and subcutaneous tissue disorders: Rash, dermatitis, pruritus.
Overdosage
Symptoms: Nausea, vomiting, dizziness, abdominal pain, diarrhoea, headache apathy, depression and confusion. Management: Symptomatic and supportive treatment.
Drug Interactions
May decrease plasma concentrations of nelfinavir and atazanavir. Increased risk of hypomagnesaemia with diuretics. May increase plasma concentration of tacrolimus, methotrexate. May decreased absorption of itraconazole, ketoconazole, posaconazole, erlotinib. May decrease metabolism of diazepam, phenytoin, cilostazol. May reduce the antiplatelet activity of clopidogrel. May increase bioavailability of digoxin.
Food Interaction
Decreased serum concentration with St John's wort.
Lab Interference
May cause false-positive result in diagnostic tests for neuroendocrine tumours.
Action
Omeprazole is a substituted benzimidazole gastric antisecretory agent and is also known as proton pump inhibitor (PPI). It blocks the final step in gastric acid secretion by specific inhibition of adenosine triphosphatase (ATPase) enzyme system present on the secretory surface of the gastric parietal cell. Both basal and stimulated acid are inhibited.
Onset: Antisecretory: Approx 1 hour.
Duration: Up to 72 hours.
Absorption: Rapid but variably absorbed from the gastrointestinal tract. Bioavailability: Approx 30-40%. Time to peak plasma concentration: 0.5-3.5 hours.
Distribution: Enters breast milk. Plasma protein binding: Approx 95%.
Metabolism: Metabolised in the liver primarily by CYP2C19 isoenzyme to hydroxyl-omeprazole; and lesser extent by CYP3A4 to omeprazole sulfone.
Excretion: Mainly via urine (approx 77% as metabolites, small amount as unchanged drug); faeces (small amount). Elimination half-life: 0.5-3 hour.
Storage
Intravenous: Store below 25°C. Protect from light and moisture. Oral: Store below 25°C. Protect from light and moisture.
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).
Disclaimer: This information is independently developed by CIMS based on omeprazole from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to CIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, CIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 CIMS. All rights reserved. Powered by CIMSAsia.com
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