Omeprazole vs Lansoprazole

Overview

What is each medicine used for?

Key differences between Omeprazole and Lansoprazole

• Chemically they are different drugs, but both block the proton pump in stomach cells, so their overall effect on acid is similar for equivalent effective doses.
• Formulations differ (capsules, dispersible products, brands); some people find one easier to swallow or better tolerated.
• Interaction profiles overlap because both are PPIs — either can affect absorption of certain other medicines; pharmacists often advise spacing or timing.
• Cost, availability, and local guidelines sometimes influence which PPI is prescribed first.

Side effects: how do they compare?

• Common effects for both include headache, diarrhoea, constipation, nausea, abdominal pain, and wind. Most are mild and may settle with time.
• Long-term acid suppression is associated with possible long-term considerations (for example bone health, B12, magnesium in some patients); prescribers review ongoing need.
• Serious allergic reactions or severe diarrhoea are uncommon but need prompt medical attention.
• Neither PPI is “gentler” for everyone — individual experience varies.

Safety and who may need extra GP or pharmacist advice

• Do not use PPIs long term for undiagnosed “indigestion” without review — certain symptoms need endoscopy or other tests.
• If you take anti-inflammatory painkillers (NSAIDs) regularly, your prescriber may use a PPI to protect the stomach in some situations; this still needs monitoring.
• Discuss use in pregnancy or breastfeeding with your GP or midwife.
• Tell your clinician about all medicines, including anticoagulants, antiplatelets, and HIV treatments, because PPIs can matter for absorption and monitoring.

How your prescriber may choose between them

• Your doctor considers your symptoms, examination findings, whether you have had investigations, and any alarm features.
• They may prefer a particular PPI if you have tried one before, if a certain formulation suits you, or if interactions make one choice safer.
• Stepping down or stopping PPIs after symptom control is sometimes appropriate — this should be planned with advice rather than stopped abruptly if you have been on high doses long term.

When to speak to your GP or pharmacist

• If heartburn persists despite treatment, or returns as soon as you stop.
• If you have difficulty swallowing, vomiting blood, black stools, unintended weight loss, or persistent vomiting.
• Before adding new regular medicines, including ibuprofen or aspirin bought from a shop.
• If you want to know whether you still need a PPI you have taken for months or years.

Read the full medicine guides

Each DrugABC medicine page covers uses, how to take it, interactions, pregnancy, and more — for reference alongside what your clinician tells you.

• OmeprazoleUses, side effects, dosage topics →
• LansoprazoleUses, side effects, dosage topics →

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