People taking a common blood pressure medicine are being urged to check their tablets after regulators warned some boxes may contain the wrong pills.
The Medicines and Healthcare products Regulatory Agency (MHRA) said packs of ramipril may have been mistakenly filled with amlodipine tablets, another kind of blood pressure medication that works in a different way.
The alert applies to 5mg ramipril packs made by Crescent Pharma Limited.
Patients should check whether their medication has the batch number GR164099, which is printed on the outer carton.
If the blister strips inside the pack are labelled amlodipine, they should be returned to the pharmacy.
Packs containing correctly labelled ramipril tablets do not need to be returned.
The MHRA said the mix-up appears to have happened during packaging at the factory, which manufactures both medicines.
Because both drugs are used to treat high blood pressure, the risk was low, the regulator added.
The most likely effect if the wrong tablets are taken is dizziness, caused by blood pressure falling too low.
Anyone who has taken the wrong tablets and feels unwell should seek medical advice and take the medicine with them.
Pharmacies and healthcare professionals have also been instructed to return any remaining stock from the affected batch.
Shareen Doak, deputy director of benefit–risk evaluation at the Medicines and Healthcare products Regulatory Agency, said: ‘If you have an affected pack and think you may have taken Amlodipine by mistake and are experiencing side effects, please seek immediate medical advice.
‘Take the leaflet and any remaining tablets with you to your pharmacy or GP practice.
‘Any suspected adverse reactions should also be reported via the MHRA Yellow Card scheme.’
Ramipril is a type of drug known as an ACE inhibitor, which lowers blood pressure by blocking a hormone that normally causes blood vessels to tighten.
This allows the vessels to relax and widen, reducing strain on the heart and improving blood flow.
Amlodipine belongs to a class called calcium channel blockers. It works by preventing calcium from entering the muscle cells in the walls of blood vessels, helping them relax and widen so blood can flow more easily and blood pressure falls.
Both medicines are commonly prescribed to treat high blood pressure and reduce the risk of heart attacks and strokes, although they act on the body through different biological pathways.
Ramipril is available on prescription as tablets, capsules or liquid and is one of the UK’s most commonly prescribed medicines, with more than 35 million prescriptions issued between 2024 and 2025.
Concerns were raised last year when it emerged that ramipril could trigger a debilitating cough that takes up to three months to disappear.
Ace inhibitors, which also include lisinopril and captopril, can also lead to the accumulation of proteins in the airways that cause irritation.
