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
• Over 60: No special problems
• Driving and hazardous work: No special problems
• Alcohol: Avoid, alcohol irritates the stomach