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Omeprazole
Please note: these are basic guidelines, refer to your doctor for a professional medical opinion.
Popular brand names:
Altosec, Losec, Omez
Drug group:
Anti-ulcer drug
Prescription needed?
Yes (except some short-term OTC treatments)
What does it do?
Omeprazole is used to treat a number of conditions involving stomach acid:
Gastro-oesophageal reflux disease (GORD) – where stomach acid rises into the oesophagus
Zollinger-Ellison syndrome - where the stomach produces large quantities of acid which leads to ulceration
Peptic ulcers –omeprazole is used either alone, or in combination with a 7-day course of antibiotics (to eradicate Helicobacter pylori bacteria - the main cause of peptic ulcers)
Over-the-counter Omeprazole is available for the short-term relief of acid reflux symptoms such as heartburn in adults over 18 years old
How does it work?
Omeprazole is a proton pump inhibitor - it reduces the amount of acid produced by the stomach, thereby reducing acid reflux and preventing or treating stomach ulceration.
How should it be used?
Omeprazole may mask the symptoms of stomach cancer - it is important to first rule out the possibility of this disease (a gastro-scope may be required before treatment is started)
Best taken in the morning before food
Avoid spicy/acidic foods and alcohol – may aggravate the underlying condition
Omeprazole is very sensitive to moisture - do not transfer to another container, and use within 3 months of opening
What is the typical dosage?
For over-the-counter preparations, follow the instructions and call your doctor if symptoms worsen.
Your doctor will recommend a dosage tailored to your need, but typically:
10–40mg daily (sometimes up to 120mg daily), once daily or 2x daily for doses above 80mg
GORD: usually a 4-12 week course
Ulcers: usually a 4-8 week course, but may be given for longer to prevent ulcers in high-risk patients (eg those taking long-term non-steroidal anti-inflammatory drugs /NSAIDs)
How quickly will it start to work?
2–5 hours
How long will the effects last?
Up to 24 hours
When should I stop using it?
If prescribed, do not stop the drug without consulting your doctor.
Is it safe for prolonged use?
Long-term use of omeprazole may increase the risk of: intestinal infections (such as Salmonella and Clostridium difficile), hip fractures in postmenopausal women, and vitamin B12/magnesium deficiency (due to reduced absorption in the intestine).
What are the possible side effects?
The following have been reported:
More common: headache, diarrhoea/constipation, nausea/ vomiting (all are usually mild and often diminish with continued use of the drug)
Report to your doctor before taking your next dose if you experience: rash
What other considerations are important?
Dosage may be adjusted by your doctor under certain conditions.
Certain health problems: liver problems
Other medicines: warfarin, phenytoin, clopidogrel, ciclosporin, tacrolimus, atazanavir, ketoconazole, itraconazole
Pregnancy and breast-feeding: No evidence of risk in pregnancy, safety in breast-feeding not established, discuss with your doctor
Children: Not usually recommended <1 year, reduced doses in older children