Nifedipine is a calcium channel blocker medicine used to treat high blood pressure (hypertension).
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.
Nifedipine is only available on prescription.
It comes as tablets or capsules. It also comes as a liquid or drops to swallow.
Who can take nifedipine
Most adults aged 18 and over can take nifedipine. It's occasionally prescribed for children.
Who may not be able to take nifedipine
Nifedipine is not suitable for some people.
Check the leaflet provided with the medicine to make sure nifedipine is safe for you. Tell your doctor if you:
- have ever had an allergic reaction to nifedipine or any other medicine
- have liver disease
- have any heart problems (other than high blood pressure), including a recent heart attack, heart failure or unstable angina
- have diabetes
Dosage and strength
Nifedipine comes as:
- 5mg and 10mg standard capsules
- 10mg, 20mg, 30mg, 40mg and 60mg slow-release tablets and capsules
Your dose of nifedipine depends on why you need the medicine and what kind your doctor has prescribed.
To decide the correct dose for you, your doctor will check your blood pressure. The usual starting dose is:
- standard capsules or liquid – 5mg, taken 3 times a day (every 8 hours)
- slow-release tablets or capsules – 10mg, taken twice a day (every 12 hours), or 20 to 30mg, taken 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.
How to take it
Nifedipine is very sensitive to light, so make sure you take your tablet or capsule as soon as you take it out of the packet.
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.
It usually does not matter if you take nifedipine with or without food, but check the leaflet of the brand you're taking because the advice can vary.
There are several brands of slow-release nifedipine, which may not all be the same. Make sure you stick to the same brand if possible and follow the directions on how to take it carefully.
With some of the slow-release tablets, you might notice what looks like a whole tablet in your poo. Do not worry, this is normal. It's just the outer shell of the tablet which your body has not digested.
If you're taking nifedipine as a liquid, shake the bottle well. The medicine will come with a plastic syringe or spoon to help you take the right amount. If you do not have a plastic syringe or spoon, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount.
Take nifedipine even if you feel well, as you will still be getting the benefits of the medicine.
Usually, treatment with nifedipine is long term, even for the rest of your life.
Changing your dose
If the starting dose is not working well enough (your blood pressure does not 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:
- standard capsules or liquid – 20mg, taken 3 times a day (total of 60mg a day)
- slow-release capsules or tablets – 40mg, taken twice a day, or 90mg once a day (total of 80mg or 90mg a day)
If you 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 2 doses 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.
If you take too much
The amount of nifedipine that can lead to an overdose varies from person to person.
Taking too much nifedipine can make you feel:
- like your heart is not beating normally (irregular heartbeats)
- sick (nausea)
- you take more than your prescribed dose of nifedipine
Go to 111.nhs.uk or call 111
If you go to A&E, 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.
Stopping taking nifedipine
Talk to your doctor if you want to stop taking nifedipine. Stopping may cause your blood pressure to go up, and this may increase your risk of heart attack and stroke.
If you're bothered by any side effects, your doctor may be able to prescribe you a different medicine.
Common side effects
These common side effects of nifedipine happen in more than 1 in 100 people. There are things you can do to help cope with them:
Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or lasts more than a few days.
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 contact 111 straight away if the whites of your eyes turn yellow, or your skin turns yellow although this may be less obvious on brown or black skin. These can be signs of liver problems.
Go to 111.nhs.uk or call 111.
- you get chest pain that does not stop after a few minutes, or is new or worse if you already have angina
Chest pain is a possible sign of a heart attack and needs to be checked as soon as possible.
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to nifedipine.
These are not all the side effects of nifedipine. For a full list, see the leaflet inside your medicine packet.
Nifedipine and pregnancy
Nifedipine can be taken during pregnancy, but talk to your doctor if you're pregnant or trying to get pregnant to see if taking nifedipine is right for you.
Nifedipine and breastfeeding
If your doctor or health visitor says your baby is healthy, it's OK to take nifedipine while you're breastfeeding.
Nifedipine passes into breast milk in very small amounts and has not been known to cause side effects in breastfed babies.
If you notice that your baby is not feeding as well as normal, seems unusually sleepy, looks a lot more pale than they usually do, or if you have any other concerns about your baby, then talk to your health visitor, midwife, pharmacist or doctor as soon as possible.
Nifedipine and fertility
There's no clear evidence to suggest that taking nifedipine reduces fertility in either men or women.
If you're trying for a baby, or having problems conceiving while on nifedipine, then speak to your doctor.
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 affect the way nifedipine works.
Tell your doctor if you're taking any of these medicines before starting nifedipine:
- the antibiotics clarithromycin, erythromycin or rifampicin
- calcium channel blockers like diltiazem or verapamil
- the antifungal medicines fluconazole or itraconazole
- medicines for HIV or hepatitis C
- the epilepsy medicines carbamazepine, phenytoin, phenobarbital (phenobarbitone), sodium valproate, valproic acid or primidone
- tacrolimus, a medicine used for preventing rejection of organ transplants or for treating conditions caused by an overactive immune system
- cimetidine, an acid-suppressing medicine
- the antidepressants fluoxetine or nefazodone
- digoxin, a medicine for heart problems
Mixing nifedipine with herbal remedies and supplements
St John's wort, a herbal medicine taken for depression, is thought to affect 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.
There's not enough information to say that other herbal remedies and supplements are safe to take with nifedipine. They're not tested in the same way as pharmacy and prescription medicines. They're generally not tested for the effect they have on other medicines.
HealthUnlocked contains information from NHS Digital, licensed under the current version of the Open Government Licence