Drug class · Digestive
Proton pump inhibitors
Also known as: PPIs, acid suppressants
The strongest acid-reducing medicines (omeprazole, lansoprazole, pantoprazole, esomeprazole), which heal ulcers and reflux by shutting down the acid pumps in the stomach lining.
- Biological target
- Gastric proton pump (H+/K+ ATPase)
- Also called
- PPIs, acid suppressants
Mechanism of action
PPIs irreversibly block the hydrogen-potassium ATPase, the proton pump in parietal cells that secretes acid as the final common step of every stimulus. Acid output falls by over 90% and recovers only as new pumps are made, so the effect outlasts the drug. Taken 30-60 minutes before breakfast when the pumps are most active. H2 blockers (famotidine) are the milder alternative.
Members of the class
Members with a page on this site are linked.
Conditions treated
Class effects
- Headache, nausea, bowel changes
- Low magnesium and B12 with long use
- Small increase in gut infections and fractures
Cautions
- Lowest dose, regular review; rebound acid after stopping
- Alarm features (weight loss, swallowing difficulty, bleeding) need endoscopy first
- Omeprazole reduces the activation of clopidogrel
Class warnings
- PPIs can mask gastric cancer; long-term use is associated with low magnesium, fractures, C. difficile infection, vitamin B12 deficiency and subacute cutaneous lupus. The lowest effective dose is used and the need reviewed regularly. UK
Class interactions
| With | Effect | Source |
|---|---|---|
| Clopidogrel (omeprazole and esomeprazole) | Reduced activation of clopidogrel; lansoprazole or pantoprazole preferred. | UK |
| Drugs whose absorption needs gastric acid (rilpivirine, atazanavir, itraconazole, ketoconazole, some cancer medicines) | Reduced absorption and effect; some combinations contraindicated. | UK |
| Methotrexate (high dose) | Reduced elimination and toxicity; the PPI may be withheld. | UK |
| Warfarin, digoxin, phenytoin, levothyroxine | Altered levels or absorption; monitoring advised. | UK |
Therapeutic duplication. Two PPIs together, or a PPI with an over-the-counter omeprazole product, duplicate acid suppression and its long-term risks. UK
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