The NHS has issued a reminder to the millions of people in the UK taking amlodipine for high blood pressure to avoid consuming grapefruit or grapefruit juice. The warning comes as the medication, a calcium channel blocker, is prescribed to manage hypertension and prevent angina, with nearly 35 million prescriptions issued annually in England alone.
Why grapefruit is dangerous with amlodipine
According to Harvard Health, grapefruit contains compounds that inhibit the liver and gut enzyme CYP3A4, which normally breaks down amlodipine. This can lead to a buildup of the drug in the bloodstream, increasing the risk of side effects such as excessive dizziness, flushing, and dangerously low blood pressure. The NHS states on its website: "Do not eat grapefruit or drink grapefruit juice while taking amlodipine because it can increase the chance of side effects."
Common side effects of amlodipine
Like all medicines, amlodipine can cause side effects, although not everyone experiences them. Common side effects include swelling in the ankles, feet and legs (oedema), headaches, dizziness, sleepiness, a fast heartbeat or palpitations, facial flushing, tummy pain, nausea, constipation or diarrhoea, and fatigue. These side effects are generally mild but should be reported to a pharmacist or doctor if they persist.
Serious side effects and what to do
Serious side effects are rare but can occur. These include allergic reactions (anaphylaxis), swelling of the pancreas (acute pancreatitis), and Stevens-Johnson syndrome, a severe skin reaction causing blistering, painful sores, skin peeling, and flu-like symptoms. In very rare cases, amlodipine can trigger a heart attack. The NHS advises anyone experiencing serious side effects to call NHS 111 immediately.
Patients are encouraged to speak to a pharmacist or doctor about any side effects that bother them or do not go away. Lifestyle changes, including diet and exercise, are often recommended alongside amlodipine to manage blood pressure, but grapefruit must be avoided entirely.
