The NHS has issued a two-week warning over omeprazole, a common drug used to relieve heartburn and acid reflux. The health service advises that people who buy the medication without a prescription should not take it for longer than two weeks.
What is omeprazole?
Omeprazole is a proton pump inhibitor (PPI) that works by reducing the amount of acid produced in the stomach. It is commonly used to treat and prevent a range of acid-related symptoms and conditions, including stomach ulcers, heartburn, gastro-oesophageal reflux disease (GORD), the stomach infection Helicobacter pylori, and discomfort from severe reflux in children.
The drug is available in several forms, including tablets, capsules and liquid, with the dosage depending on the reason it is being taken. It is one of the most widely prescribed medicines in the UK, with NHS data showing that 73 million PPIs were prescribed in England in 2022/23.
NHS advice on dosage and missed doses
The NHS says: "Do not take omeprazole for longer than 2 weeks if you bought it without a prescription. See a GP if your symptoms get worse or do not get better."
The health service adds: "If you forget to take a dose of omeprazole, take it as soon as you remember, unless it's nearly time for your next dose. If it's nearly time for your next dose, skip the dose you missed and take your next dose at the usual time. Do not take 2 doses at the same time to make up for a missed one."
Side effects and when to seek help
Acid reflux often causes heartburn and can be triggered by stress, excess weight, eating too quickly or consuming alcohol, caffeine and chocolate. While it can be uncomfortable, stomach acid is needed for digestion and protects against harmful microbes in food.
Taking too much omeprazole can sometimes be dangerous. The NHS advises people to call 111 if they or their child have had more omeprazole than it says on the packet, leaflet or prescription.
Common side effects of omeprazole include headaches, stomach pain, feeling sick (nausea) or being sick (vomiting), constipation or diarrhoea, and farting more than usual.
Possible serious side effects include having a very low level of vitamin B12, which can cause symptoms such as tiredness, dizziness, or muscle twitches or weakness; weakened bones, which can break more easily if you have a fall or injury; an allergic reaction (anaphylaxis), which can cause symptoms such as a swollen throat or tongue, a raised, itchy rash or difficulty breathing; and a type of lupus that can cause rashes (particularly on parts of the body exposed to the sun) and joint pain.
The NHS adds: "The chance of getting serious side effects can be higher if you take omeprazole for a long time (a year or more)." The health service advises people to call 111 if they believe they are having serious side effects from taking the drug.
