Felodipine: uses, side effects and cautions

Felodipine is used to treat high blood pressure and angina. It relaxes and widens blood vessels, which increases blood flow and the oxygen supply to the heart. It belongs to the calcium channel blocker class and is prescription only; the NHS lists the brands Cardioplen, Delofine and Vascalpha.

Most adults can take felodipine. It is unsuitable if you have had an allergic reaction or serious side effect to felodipine or similar medicines, or if you have heart failure, heart disease, heart valve problems or a recent heart attack, a fast heartbeat, liver problems, low blood pressure or gum problems. Tell the prescriber about any medical condition before starting.

Felodipine comes as tablets taken once a day in the morning. Swallow the tablet whole with a drink of water and take it at the same time each day. Check the packet or leaflet to see whether it should be taken with food. Your doctor may change the dose depending on how well it works and how you cope with side effects.

Treatment is usually long term. For a missed dose, take it when you remember unless the next is nearly due, in which case skip it; do not double. An extra dose is unlikely to cause problems but can sometimes be dangerous, so get medical advice if you take too much. Do not stop unless a doctor tells you to, since stopping suddenly can be dangerous.

Common effects are gradual ankle swelling, headaches, flushing, stomach pain, dizziness, nausea and vomiting, and a more noticeable heartbeat. Speak to a pharmacist or doctor if they bother you or do not go away. If dizziness or tiredness affects you, do not drive, ride a bike or use machinery until it has stopped.

Rare serious effects: anaphylaxis with a swollen throat or tongue, itchy raised rash and breathing difficulty, and angioedema, which is sudden swelling of part of the body. Call NHS 111 if you think you may be having a serious side effect.

Taking felodipine at the same point every morning, for instance with a regular drink at breakfast, makes it harder to forget and keeps the effect steady across the day. If your packet says anything about food, follow that rather than guessing, because the NHS leaves the food instruction to the individual product.

Tell dental and medical teams that you take felodipine, since gum problems are on the list of things the prescriber wants to know about before you start.

Avoid grapefruit and grapefruit juice. Alcohol can increase the risk of side effects such as low blood pressure.

Named medicine types include antibiotics such as erythromycin, antifungals such as ketoconazole, epilepsy medicines, stomach ulcer medicines and HIV medicines. The herbal remedy St John's wort is also named. Ask a pharmacist before taking any other medicine, herbal remedy, vitamin or supplement.

Felodipine is not recommended in pregnancy. If you are expecting or planning a pregnancy, tell your doctor, who may suggest switching or stopping before conception. It can be taken while breastfeeding, but check first with a pharmacist or doctor. The NHS page has no fertility information.

Amlodipine, nifedipine and lercanidipine are other calcium channel blockers; ACE inhibitors, ARBs and beta blockers are other blood pressure options. Report suspected side effects via the Yellow Card scheme.