Nifedipine is a medicine used to treat high blood pressure.
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.
- 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.
- Don’t eat grapefruit or drink grapefruit juice while you're taking nifedipine. It can make side effects worse.
- If you get severe vomiting or diarrhoea from a stomach bug or illness, tell your doctor. You may need to stop taking nifedipine for a while until you feel better.
- 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.
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
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 will I 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 nifedipine 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 80 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 been 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 or chew them, or open up the capsules unless your doctor or pharmacist has said you can.
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.
Don't 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.
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 is due. In this case leave out that 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 is due. In this case leave out that dose and take your next dose at the usual time.
Never take a double dose to make up for a forgotten one.
If you forget doses often, 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, feeling sick, confused, and sleepy.
The amount of nifedipine that can lead to an overdose varies from person to person.
If you take too much nifedipine by accident, call your doctor or go to your nearest hospital accident and emergency (A&E) department straight away.
If you need to go to hospital, don't drive yourself - get someone else to take you or call for an ambulance. Take the nifedipine packet or the leaflet inside it plus any remaining medicine with you.
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:
- a pounding heartbeat
- swollen ankles
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 eyes - this can be a sign 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 to nifedipine.
A serious allergic reaction is an emergency. Contact a doctor straight away if you think you or someone around you is having a serious allergic reaction.
The warning signs of a serious allergic reaction are:
- getting a skin rash that may include itchy, red, swollen, blistered or peeling skin
- tightness in the chest or throat
- having trouble breathing or talking
- swelling of the mouth, face, lips, tongue, or throat
These are not all the side effects of nifedipine. For a full list see the leaflet inside your medicines packet.
How to cope with side effects
What to do about:
- headache - make sure you rest and drink plenty of fluids. Don't 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.
- 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.
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.
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.
Tell your doctor if you're trying to get pregnant, are already pregnant or if you're breastfeeding.
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.
Tell your doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.
How does nifedipine work?
How long does nifedipine take to work?
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?
Can I drink alcohol with it?
Is there any food or drink I need to avoid?
Are there similar medicines to nifedipine?
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?