What it is used for
- Heartburn and acid reflux (GERD)
- Stomach and duodenal ulcers
- Helicobacter pylori infection (as part of combination therapy)
- Zollinger-Ellison syndrome
- Protecting the stomach lining in people taking long-term NSAIDs
How it works
Omeprazole switches off the acid-producing pumps in the cells lining the stomach. By strongly reducing how much acid the stomach makes, it relieves acid-related symptoms and gives irritated or ulcerated tissue a chance to heal.
How it is taken
Comes as capsules, tablets, dispersible (orodispersible) tablets, granules for an oral suspension, and in some settings an intravenous form. It is usually taken by mouth before food, and many forms should be swallowed whole rather than crushed or chewed. Take it exactly as your doctor, pharmacist, or the product label directs, and do not change how long you use it without advice.
No doses here on purpose. The right strength and schedule depend on you — only a doctor or pharmacist should set them. Always follow your prescription and the label.
Common side effects
- Headache
- Nausea or stomach pain
- Diarrhea or constipation
- Wind (flatulence)
- Dizziness
Serious effects — get help
- Signs of a severe allergic reaction (swelling of the face, lips, throat, trouble breathing)
- Severe, watery, or bloody diarrhea (possible intestinal infection)
- Persistent muscle cramps, weakness, or irregular heartbeat (possible low magnesium)
- Severe skin rash, blistering, or peeling
- Joint pain with a rash on cheeks or arms that worsens in sunlight
- New or worsening kidney problems (much less urine, swelling)
If a reaction is severe — for example trouble breathing, swelling of the face or throat, or collapse — go to the nearest emergency room now or call your local emergency number. Do not wait for an online consultation.
Interactions to watch
- Clopidogrel (blood thinner) — effect may be reduced
- Some HIV medicines, certain antifungals, and other drugs needing stomach acid to be absorbed
- Methotrexate
- Warfarin and other anticoagulants
- Digoxin
- Citalopram and certain antidepressants
Who should take care
- Tell your clinician if you have liver disease
- Discuss use in pregnancy or while breastfeeding with your clinician
- Long-term or high-dose use may affect bone strength, vitamin B12, and magnesium levels
- Seek review if you have unexplained weight loss, difficulty swallowing, vomiting blood, or black stools before starting
- Tell your pharmacist about all other medicines, as PPIs can mask symptoms of more serious conditions