The NHS has issued a warning about the potential risks associated with long-term use of omeprazole, a common tablet used to treat heartburn and indigestionCharlotte Smith Senior Lifestyle Content Editor and Lucy John
12:59, 27 Sep 2025
PPIs are medications that reduce stomach acid production(Image: Getty)
Omeprazole is among the most frequently prescribed medications in the UK, with latest statistics revealing 73 million NHS prescriptions for proton pump inhibitors (PPIs), such as omeprazole, were issued in England during 2022-23. Further data indicates that PPI usage impacts approximately 15% of the population.
PPIs are medications that reduce stomach acid production. They function by blocking the proton pumps, enzymes situated in the stomach lining that generate acid.
This alleviates problems including acid reflux and heartburn.
Other medical conditions managed by PPIs include indigestion, healing of stomach ulcers, gastro-oesophageal reflux disease (GORD), and gastroesophageal reflux disease (GERD).
It can also be utilised, in combination with antibiotics, to treat the stomach infection, helicobacter pylori.
Frequently prescribed PPIs include omeprazole (Prilosec), esomeprazole (Nexium), lansoprazole (Prevacid), pantoprazole (Protonix), and rabeprazole (AcipHex).
While they prove effective, especially for prolonged treatment courses, there are potential dangers linked with long-term usage, reports the Mirror.
The NHS has issued a warning regarding this on its website. The guidance states: “Do not take omeprazole for longer than two weeks if you bought it without a prescription. See a GP if your symptoms get worse or do not get better.”
One of the risks associated with prolonged use of PPIs is an increased likelihood of a bacterial infection known as clostridioides difficile.
This bacterium can cause an infection in the intestines, leading to diarrhoea and other symptoms such as abdominal pain and fever.
This bacterium typically causes illness when antibiotics disrupt the balance of normal gut bacteria, allowing clostridioides difficile to proliferate and produce toxins. Symptoms include:
watery or offensive stools, sometimes with mucus or bloodabdominal pain or tendernessfeverloss of appetitenausea
In most individuals, clostridioides difficile coexists harmlessly in the intestines alongside various other bacteria. However, when antibiotics wipe out the beneficial bacteria, they can rapidly multiply.
These toxins irritate the colon, resulting in infection symptoms.
Clostridioides difficile can be triggered by medication disrupting the natural gut flora. It can also be spread through spores that survive on contaminated surfaces.
It primarily affects at-risk groups, including the elderly and those with weakened immune systems.
How to take omeprazole:
Omeprazole usually comes in tablets, capsules, and a liquid form for ingestion. Some tablets can be dissolved in water.
The dosage and duration of treatment depend on the specific type of omeprazole you are using and the reason for its use. It is generally taken once or twice daily.
Some individuals may only need it for a few days, whilst others might require continued use for several weeks, months, or even years. Always check the packaging or leaflet that comes with your medication.
If you’re unsure about how to take it or experience any problems, seek advice from a pharmacist or doctor.
The NHS says when taking omeprazole:
try to take it at the same time each morning if you take it once a day, or at the same time each morning and evening if you take it twice a dayyou can take it with or without foodswallow tablets and capsules with water – do not chew or crush capsules or tablets labelled “enteric coated” or “gastro resistant”
It adds: “Ask a pharmacist for advice if you have problems swallowing pills or capsules. They may be able to suggest different ways to take your medicine.”
Side effects of omeprazole:
Like all medicines, omeprazole can cause side-effects, but not everyone gets them. Common side effects of omeprazole include:
a headachestomach painfeeling sick (nausea) or being sick (vomiting)constipation or diarrhoeafarting more than usual
The NHS says: “Omeprazole will not usually affect your ability to drive, ride a bike or use machinery. But if you feel dizzy or have problems with your vision after taking it, wait until you no longer have these side-effects.”