Nifedipine - EM Doctors

1. About nifedipine

Nifedipine is a medicine used to treat high blood pressure.

If you have high blood pressure, taking nifedipine helps to prevent future heart disease, heart attacks and strokes.

Nifedipine is also used to prevent chest pain caused by angina. Occasionally, it's used to treat Raynaud's phenomenon and chilblains.

The medicine is only available on prescription.

It comes as tablets or capsules. It also comes as a liquid or drops to swallow, but these need to be ordered specially.

2. Key facts

Nifedipine lowers your blood pressure and makes it easier for your heart to pump blood around your body.
The most common side effects include headache, flushing, constipation, feeling tired and swollen ankles. These usually improve after a few days of treatment.
Do not eat grapefruit or drink grapefruit juice while you're taking nifedipine. It can make side effects worse.
Nifedipine is also called by various brand names, for example Adalat, Adipine, Coracten, Fortipine, Nifedipress, Tensipine and Valni. If the brand name has other letters after it (XL, LA, SR, MR, or Retard), it means that the nifedipine is released slowly and evenly throughout the day.

3. Who can and can't take nifedipine

Nifedipine is mostly used for adults aged 18 years and over. It's occasionally prescribed for children.

Nifedipine isn't suitable for some people.

To make sure nifedipine is safe for you, tell your doctor if you:

have had an allergic reaction to nifedipine or any other medicine in the past
are trying to get pregnant, are already pregnant or you are breastfeeding
have liver disease
have any heart problems (other than high blood pressure), including a recent heart attack, heart failure or unstable angina
have diabetes

4. How and when to take it

Take nifedipine exactly as your doctor has told you, and follow the directions on the label. If you're not sure, check with your doctor or pharmacist.

How much to take

Your dose of nifedipine depends on why you need the medicine and what kind your doctor has prescribed.

Nifedipine comes as "short acting" (immediate-release) capsules, or as "long acting" (slow-release) tablets or capsules. If you have liquid nifedipine, it works like the short acting capsules. Long acting nifedipine capsules or tablets release the medicine evenly throughout the day. This means you don't need to take them as often.

To decide the correct dose for you, your doctor will check your blood pressure. Depending on why you're taking nifedipine, the usual starting dose is:

short acting capsules or liquid: 5mg 3 times a day (every 8 hours)
long acting tablets or capsules: 10mg twice a day (every 12 hours) or 20 to 30mg once a day (every 24 hours, preferably in the morning)

If a doctor prescribes it for your child, the dose will usually be lower. It will depend on how old your child is and how much they weigh.

Will my dose go up or down?

If the starting dose isn't working well enough (your blood pressure doesn't come down enough, or you are still getting symptoms), you may need to increase your dose. If you're bothered by side effects, you may need to stay on a lower dose.

The usual maximum doses of nifedipine are:

short acting capsules or liquid: 20mg 3 times a day (total of 60mg a day)
long acting capsules or tablets: 40mg twice a day or 90mg once a day (total of 80mg or 90mg a day)

How to take it

Take your nifedipine capsule or tablet as soon as you've taken it out of the blister pack. Nifedipine is very sensitive to light and won't work properly if it's left out of the packet too long.

You can take nifedipine at any time of day, but try to make sure it's around the same time or times every day.

Swallow the capsules or tablets whole with a drink of water. Do not break, crush, chew or open up the capsules unless your doctor or pharmacist has said you can.

You can take short acting and long acting nifedipine with or without food.

With some of the long acting tablets you might notice what looks like a whole tablet in your poo. Don't worry, this is normal. It's just the outer shell of the tablet which your body hasn't digested.

Do not eat or drink grapefruit or grapefruit juice while you're taking this medicine. Grapefruit can increase the concentration of nifedipine in your body and make side effects worse.

If you're taking nifedipine as a liquid, it will usually be made up for you by your pharmacist. The medicine will come with a plastic syringe or spoon to help you take the right amount. If you don't have a plastic syringe or spoon, ask your pharmacist for one. Do not use a kitchen teaspoon as it won't give the right amount.

Important

Take nifedipine even if you feel well, as you will still be getting the benefits of the medicine.

What if I forget to take it?

If you forget to take a dose and you usually take nifedipine:

3 times a day: leave out that dose and take your next dose at the usual time.
twice a day: take it as soon as you remember unless it is less than 4 hours until your next dose. In this case leave out the missed dose and take your next dose at the usual time.
once a day: take it as soon as you remember unless it is less than 12 hours until your next dose. In this case leave out the missed dose and take your next dose at the usual time.

Never take a double dose to make up for a forgotten one.

If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.

What if I take too much?

If you take too much nifedipine by accident, contact your doctor or go to your nearest hospital straight away.

An overdose of nifedipine can cause dizziness and irregular heartbeats, and make you feel sick (nausea), confused and sleepy.

The amount of nifedipine that can lead to an overdose varies from person to person.

Urgent advice: Call your doctor or go to A&E straight away if you take too much nifedipine

If you need to go to hospital, do not drive yourself - get someone else to drive you or call for an ambulance.

Take the nifedipine packet or leaflet inside it plus any remaining medicine with you.

Find your nearest hospital A&E department.

5. Side effects

Like all medicines, nifedipine can cause side effects, although not everyone gets them. Side effects often improve as your body gets used to the medicine.

Common side effects

These common side effects happen in more than 1 in 100 people. They are usually mild and short-lived.

Talk to your doctor or pharmacist if the side effects bother you or last for more than a few days:

headaches
dizziness
flushing
a pounding heartbeat
swollen ankles
constipation

Serious side effects

Serious side effects after taking nifedipine are rare and happen in less than 1 in 1,000 people.

Stop taking nifedipine and tell a doctor straight away if you get:

yellow skin or the whites of your eyes turn yellow - these can be signs of liver problems
chest pain that is new or worse - this side effect needs to be checked out as chest pain is a possible symptom of a heart attack

Serious allergic reaction

In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to nifedipine.

Immediate action required: Call 999 or go to A&E if:

you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
you're wheezing
you get tightness in the chest or throat
you have trouble breathing or talking
your mouth, face, lips, tongue or throat start swelling

You could be having a serious allergic reaction and may need immediate treatment in hospital.

These are not all the side effects of nifedipine. For a full list see the leaflet inside your medicines packet.

You can report any suspected side effect to the UK safety scheme.

6. How to cope with side effects

What to do about:

headaches - make sure you rest and drink plenty of fluids. Do not drink too much alcohol. Ask your pharmacist to recommend a painkiller for a headache. Paracetamol is safe to take with nifedipine. Headaches should usually go away after the first week of taking nifedipine. Talk to your doctor if they last longer than a week or are severe.
feeling dizzy - if nifedipine makes you feel dizzy, stop what you're doing and sit or lie down until you feel better.
flushing - try cutting down on coffee, tea and alcohol. It might help to keep the room cool and use a fan. You could also spray your face with cool water or sip cold or iced drinks. The flushing should go away after a few days, so try to carry on taking nifedipine for this time. If it does not go away or is causing you problems, contact your doctor.
a pounding heartbeat - if this happens regularly after you take your medicine try to take it at a time when you can sit or lie down while the symptoms are at their worst. It might also help to cut down on alcohol, smoking, caffeine and big meals as these can make the problem worse. If you are still having problems after a week or so speak to your doctor as they may need to change you to a different type of medicine.
swollen ankles - raise your legs when you're sitting down.
constipation - eat plenty of high-fibre foods such as fresh fruit and vegetables and cereals, and drink lots of water. Try to exercise regularly, for example by going for a daily walk or run. It's ok to occasionally use a laxative.

7. Pregnancy and breastfeeding

If you're trying to get pregnant or you're already pregnant, talk to your doctor about the benefits and possible harms of taking nifedipine. There may be other medicines that are safer for you.

For more information about how nifedipine can affect you and your baby during pregnancy, visit the Best Use of Medicines in Pregnancy (BUMPS) website.

Nifedipine and breastfeeding

Small amounts of nifedipine may get into breast milk, but it's generally considered safe for breastfeeding mothers and babies. Talk to your doctor if you have any concerns about taking nifedipine while you're breastfeeding.

Non-urgent advice: Tell your doctor if you're:

trying to get pregnant
pregnant
breastfeeding

8. Cautions with other medicines

If you take other medicines that lower blood pressure with nifedipine, the combination can sometimes lower your blood pressure too much. This may make you feel dizzy or faint. If this keeps happening to you, tell your doctor as your dose may need to be changed.

Some medicines can interfere with the way nifedipine works.

Tell your doctor if you're taking any of these medicines before starting nifedipine:

antibiotics: clarithromycin, erythromycin or rifampicin
calcium channel blockers: diltiazem or verapamil
the antifungal medicines: itraconazole or fluconazole
medicines for HIV or HCV (hepatitis C virus)
anti-epilepsy medicines: carbamazepine, phenytoin, phenobarbital (phenobarbitone), sodium valproate (valproic acid) or primidone
medicines to reduce immune reactions such as tacrolimus
the stomach ulcer medicine, cimetidine
the antidepressants: fluoxetine (Prozac) or nefazodone
digoxin (a medicine for heart problems)

Mixing nifedipine with herbal remedies or supplements

To be safe, speak to your pharmacist or doctor before taking any herbal or alternative remedies with nifedipine.

St John's wort, a herbal medicine taken for depression, is thought to interfere with the way nifedipine works. Talk to your doctor if you're thinking about taking St John's wort.

Ginkgo biloba and ginseng are popular supplements that may also affect nifedipine.

Important

Tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.

9. Common questions

How does nifedipine work?

Nifedipine is a type of medicine called a calcium channel blocker.

If you have high blood pressure, it works by blocking calcium going into muscles in the heart and blood vessels. Muscles need calcium to contract, so when you block the calcium, it makes the muscle cells relax. This lowers your blood pressure and makes it easier for your heart to pump blood around your body.

In angina, nifedipine works by improving the blood supply to your heart. Angina is chest pain that comes on when not enough blood gets to the muscles of the heart. It usually happens because the arteries to the heart have become hardened and narrowed. Nifedipine widens the arteries so more oxygen gets to the heart which prevents chest pain.

For Raynaud's phenomenon and chilblains, nifedipine works by relaxing and expanding blood vessels and increasing blood flow to your fingers and toes.

How long does nifedipine take to work?

Nifedipine starts to work on the day you start taking it, but it may take a couple of weeks fully take effect.

If you're taking nifedipine for high blood pressure, you may not have any symptoms. In this case, you may not feel any different when you take it. This doesn't mean that the medicine isn't working - and it's important to keep taking it. Your doctor will check to see how well it is working.

If you're taking nifedipine for angina, it will probably take a couple of weeks before you feel better. Until then, you'll still get chest pain. So make sure you have your medicine (spray or tablets) for treating angina attacks with you all the time, and use it if you need to. Talk to your doctor if your chest pain doesn't get any better after a couple of weeks. If it gets worse tell your doctor straight away.

How long will I take it for?

Is nifedipine safe to take for a long time?

What will happen if I stop taking it?

Can I come off nifedipine now my blood pressure is lower?

Even if nifedipine lowers your blood pressure successfully, it's best to carry on taking it. If you stop taking nifedipine, your blood pressure could rise back up again.

If you need blood pressure-lowering medicines, you'll probably need to take them for the rest of your life.

Remember, by keeping your blood pressure low, you're protecting yourself against having a heart attack or stroke in the future.

Can I drink alcohol with it?

Is there any food or drink I need to avoid?

Are there similar medicines to nifedipine?

For high blood pressure

There are several other calcium channel blockers which work in the same way as nifedipine. They include amlodipine, felodipine, lacidipine and lercanidipine.

There are also lots of other types of medicines to lower your blood pressure. They work in a different way to calcium channel blockers and include:

ACE inhibitors - for example ramipril and lisinopril
angiotensin receptor blockers - for example candesartan
beta blockers - for example bisoprolol
diuretics - for example bendroflumethiazide

If you can't take nifedipine or other calcium channel blockers because of side effects, you may be able to switch to another medicine. Your doctor will advise which one is best for you depending on your age, ethnicity and medical history.

For angina

There are other calcium channel blockers, such as diltiazem and verapamil, which are used for angina. There are also other medicines for angina which work in a different way. They include:

beta blockers - for example bisoprolol
nitrates - for example isosorbide dinitrate

For Raynaud's phenomenon and chilblains

Nifedipine is the medicine that's normally used to treat Raynaud's phenomenon and chilblains. Sometimes a doctor will prescribe other medicines, including angiotensin converting enzyme (ACE) inhibitors.

Are there other uses of nifedipine?

Is nifedipine addictive?

Will it affect my contraception?

Will it affect my fertility?

Can I drive or ride a bike?

Can lifestyle changes help?

You can boost the health of your heart by making some key lifestyle changes. These will also help if you have high blood pressure or angina.

Quit smoking - smoking increases your heart rate and blood pressure. Quitting smoking brings down your blood pressure and relieves heart failure symptoms. Try to avoid secondhand smoke.
Cut down on alcohol - drinking too much alcohol raises blood pressure over time. It makes heart failure worse too. Try to keep to the recommended guidelines of no more than 14 units of alcohol a week. A standard glass of wine (175ml) is 2 units. A pint of lager or beer is usually 2 to 3 units of alcohol.
Exercise - regular exercise lowers blood pressure by keeping your heart and blood vessels in good condition. It doesn't need to be too energetic - walking every day will help.
Eat well - aim to eat a diet that includes plenty of fruit and veg, wholegrains, fat-free or low-fat dairy products and lean proteins. It's a good idea to cut down on salt too. Eating too much salt is the biggest cause of high blood pressure - the more salt you eat, the higher your blood pressure will be. Aim for no more than 6g of salt a day.
Deal with stress - when you're anxious or upset, your heart beats faster, you breathe more heavily and your blood pressure often goes up. This can make heart failure worse too. Find ways to reduce stress in your life. To give your heart a rest, try napping or putting your feet up when possible. Spend time with friends and family to be social and help avoid stress.
Vaccinations - if you have heart failure, it's recommended that you have a flu jab every year and a pneumonia vaccination every 5 years. Ask your doctor about these vaccinations. You can have them free on the NHS.