3.1 PPI clinical use/key interactions/key adverse effects

PPIs are the most commonly prescribed classes of medicine for the treatment of

peptic ulcers

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gastroprotection in certain groups of patients taking mediciens increasing risk of peptic ulcers/long term like antiplatlets or NSAIDs

the reduction of gastric pH that PPI causes → reduced absorption of other medicines that require an acidic environment for effective absorption

specifically antifungal agents like iraconazole and ketocanazole.

in these situations patients are advised to consume an acidic beverage with the antifungal to ensure it is absorbed fully

Omeprazole and esomeprazole have a drug-drug interaction with the antiplatelet clopidogrel.

As patients are commonly prescribed a PPI alongside antiplatelets this is a key interaction to note

In this situation these PPIs should not be used and an alternative one e.g. lansoprazole should be prescribed.

Clostridium difficile infection risk is heightened in patients taking PPIs

due to the reduction in acid production (note H₂RAs also have this effect).

Increased risk of bone fractures especially in elderly patients taking these medicines long term.

Patients at high risk of this should be given adequate calcium and vitamin D supplementation and the ongoing need for the PPI reviewed

Hypomagnesaemia can occur with long-term use (i.e. usually after one year of treatment).

• . Ideally magnesium levels should be checked before starting a PPI and intermittently during use.