Omeprazole vs Lansoprazole
Clinical Comparison
Clinical Context
Omeprazole and lansoprazole are the two most commonly prescribed PPIs in the UK NHS. They are therapeutically equivalent for most indications. The key prescribing difference is the clopidogrel interaction — lansoprazole is preferred when a PPI is needed alongside clopidogrel.
Drug Profiles
Omeprazole
Proton pump inhibitor (PPI)
Mechanism
Irreversibly inhibits the gastric H+/K+ ATPase pump in parietal cells, suppressing basal and stimulated acid secretion
Indications
- GORD
- Peptic ulcer disease
- H. pylori eradication (with antibiotics)
- NSAID-associated ulcer prophylaxis
- Zollinger-Ellison syndrome
Common Doses
20 mg OD (40 mg for severe GORD or Zollinger-Ellison)
Route
Oral, IV
Onset & Duration
Onset 1 hour; maximum effect 2 hours; duration up to 72 hours (irreversible enzyme binding)
Lansoprazole
Proton pump inhibitor (PPI)
Mechanism
Irreversibly inhibits the gastric H+/K+ ATPase pump in parietal cells
Indications
- GORD
- Peptic ulcer disease
- H. pylori eradication
- NSAID-associated ulcer prophylaxis
- Zollinger-Ellison syndrome
Common Doses
30 mg OD (15 mg for maintenance)
Route
Oral (including orodispersible tablets)
Onset & Duration
Onset 1-2 hours; duration up to 72 hours
Key Differences
| Category | Omeprazole | Lansoprazole |
|---|---|---|
| Clopidogrel interaction | Significant CYP2C19 inhibition — reduces clopidogrel activation | Weaker CYP2C19 inhibition — preferred with clopidogrel |
| Formulations | Capsules, IV, oral suspension | Capsules and orodispersible tablets (FasTabs) |
| Equivalent doses | 20 mg | 30 mg |
| Cost (NHS) | Very low — most prescribed PPI | Very low — similar cost to omeprazole |
| Dysphagia suitability | MUPS capsules can be dispersed but less convenient | FasTabs dissolve on tongue — ideal for dysphagia |
Clopidogrel interaction
Significant CYP2C19 inhibition — reduces clopidogrel activation
Weaker CYP2C19 inhibition — preferred with clopidogrel
Formulations
Capsules, IV, oral suspension
Capsules and orodispersible tablets (FasTabs)
Equivalent doses
20 mg
30 mg
Cost (NHS)
Very low — most prescribed PPI
Very low — similar cost to omeprazole
Dysphagia suitability
MUPS capsules can be dispersed but less convenient
FasTabs dissolve on tongue — ideal for dysphagia
Key Advantages
Omeprazole
- Most widely studied PPI
- Available OTC and generic — very inexpensive
- IV formulation available for acute GI bleeding
- Extensive evidence base across all indications
Lansoprazole
- Orodispersible tablet available — useful for dysphagia and NG tubes
- Less CYP2C19 inhibition than omeprazole — preferred with clopidogrel
- Effective across all standard PPI indications
- Generic and affordable
Key Cautions
Omeprazole
- CYP2C19 inhibitor — interacts with clopidogrel (reduces activation)
- Long-term risks: hypomagnesaemia, B12 deficiency, C. difficile infection, hip fractures
- Rebound acid hypersecretion on withdrawal
- Step-down to lowest effective dose
Lansoprazole
- Same long-term PPI class risks as omeprazole
- Orodispersible tablets contain aspartame (caution in phenylketonuria)
- Diarrhoea may be slightly more common
- Same rebound risk on withdrawal
Clinical Verdict
Both are therapeutically equivalent. Use lansoprazole when the patient is on clopidogrel (to avoid CYP2C19 interaction) or has dysphagia (orodispersible tablets). Otherwise, omeprazole is the standard first-choice PPI.
Medical Disclaimer: This comparison is for educational purposes only and is not a substitute for professional medical advice. Always consult a qualified healthcare professional before making prescribing decisions. Verify all drug information with current clinical guidelines (BNF, NICE, SmPCs).
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