Candesartan is a medicine widely used to treat high blood pressure (hypertension) and heart failure.
It helps to prevent future strokes, heart attacks and kidney problems. It also improves your survival if you're taking it for heart failure.
There's some evidence that candesartan might help prevent migraines. However, candesartan is not officially approved for migraine. Your doctor would probably advise you to try other medicines first.
This medicine is only available on prescription. It comes as tablets.
Who can take candesartan
Most adults aged 18 and over can take candesartan.
Children aged 6 years and over can also take it, but only to treat high blood pressure.
Candesartan is meant for people who have tried taking blood pressure-lowering medicines called ACE inhibitors (such as ramipril and lisinopril) in the past, but had to stop taking them because of side effects such as a dry cough.
Who may not be able to take candesartan
Candesartan is not suitable for some people. To make sure it's safe for you, tell your doctor if you:
- have ever had an allergic reaction to candesartan or any other medicine
- have diarrhoea (or if you've recently had it) or you're being sick (vomiting)
- have been on a low salt diet
- recently had a kidney transplant
- have severe liver disease or a problem with the drainage of the bile from your gall bladder (biliary obstruction)
- have diabetes
- have heart, liver or kidney problems
- have low blood pressure (hypotension)
- are trying to get pregnant, are already pregnant or you're breastfeeding
Dosage and strength
The dose of candesartan you take depends on why you need the medicine. Take it as your doctor tells you.
The tablets come in strengths of 2mg, 4mg, 8mg, 16mg and 32mg.
For adults, the usual dose is:
- high blood pressure – 8mg to 32mg once a day
- heart failure – 4mg to 32mg once a day
In people with liver or kidney problems, the dose may be lower.
For children (aged 6 years and over), the usual dose to treat high blood pressure is:
- for children weighing less than 50kg, 4mg to 8mg once a day
- for children weighing 50kg or more, 4mg to 16mg once a day
How to take it
You'll usually take candesartan tablets once a day. You can take your candesartan tablet at any time of day, but try to take it at the same time every day.
You can take candesartan tablets with or without food. Swallow the tablets whole with a drink of water.
Changes to your dose
You will start on a low dose of candesartan. After a few weeks your doctor will check your blood pressure and ask you if you're getting any side effects. You may also have blood tests to check how well your kidneys are working and the amount of potassium in your blood. Your doctor will then decide whether to change your dose of candesartan.
If candesartan does not get your blood pressure down, your doctor may want to increase the dose.
If your blood pressure gets too low or you get side effects, your doctor may want to lower your candesartan dose.
Take candesartan even if you feel well, as you will still be getting the benefits of the medicine.
Usually, treatment with candesartan is long term, even for the rest of your life.
If you get ill while taking it
If you get severe diarrhoea or vomiting for any reason, contact your doctor or a pharmacist for advice.
They may recommend that you stop taking candesartan until you're better and you're able to eat and drink normally again.
If you forget to take it
If you miss a dose of candesartan, take it as soon as you remember. If you do not remember until the next day, skip the missed dose and take the next one 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.
If you take too much
An overdose of candesartan can cause low blood pressure and dizziness.
The amount of candesartan that can lead to an overdose varies from person to person.
- you've taken more than your prescribed dose of candesartan
Go to 111.nhs.uk or call 111
If you need to go to A&E, do not drive yourself. Get someone else to drive you or call for an ambulance.
Take the candesartan packet, or the leaflet inside it, plus any remaining medicine with you.
- you've taken more than your prescribed dose of candesartan and you feel dizzy or unwell
Common side effects
These common side effects of candesartan 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 does not go away.
Serious side effects
It happens rarely, but some people have serious side effects after taking candesartan.
Call a doctor or contact 111 now 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
- your skin is paler than usual, you feel tired, faint or dizzy, or you get purple spots, any sign of bleeding, sore throat and a high temperature – these can be signs of a blood or bone marrow disorder
- you get weakness, an irregular heartbeat, pins and needles and muscle cramps – these can be signs of changes in the sodium and potassium levels in your blood
Go to 111.nhs.uk or call 111
Serious allergic reaction
In rare cases, candesartan may cause a serious allergic reaction (anaphylaxis).
Taking candesartan for a long time can sometimes cause your kidneys to not work as well as they should. Your doctor will check how well your kidneys are working with regular blood tests.
Other side effects
These are not all the side effects of candesartan. For a full list see the leaflet inside your medicines packet.
Candesartan and pregnancy
Candesartan is not recommended in pregnancy. It can reduce the level of fluid around your baby, particularly if you take it in the second and third trimesters of pregnancy. This can result in long term damage to your baby's kidneys and lungs and a number of other problems.
If you're already pregnant, stop taking candesartan and talk to your doctor straight away. Usually your doctor will be able to prescribe a different medicine that is safer to take in pregnancy. Candesartan should always be stopped by the time you're 12 weeks pregnant.
Use contraception if you're taking candesartan and carefully plan any pregnancy with your GP, pregnancy specialist (obstetrician) or hospital specialist. They will review your medical condition and medicine before you get pregnant.
Most women come off candesartan before getting pregnant, but some may continue up until they have a positive pregnancy test and then stop. Your doctor will discuss what's best for you, based on your condition and the risks and benefits of candesartan.
Candesartan and breastfeeding
It might be OK to take candesartan while breastfeeding, but talk to your doctor or pharmacist first. It is best not to take candesartan if your baby was born prematurely, but your doctor will help you decide.
Candesartan passes into breast milk in very small amounts. It is unlikely to cause side effects in your baby. However, there is a very small risk that it could also lower your baby's blood pressure. Until we know more about candesartan in breastfeeding your doctor might recommend a different medicine for you to take.
If you notice that your baby is not feeding as well as usual, seems unusually sleepy, seems much paler than usual, or if you have any other concerns about your baby, talk to your health visitor, midwife or doctor as soon as possible.
Candesartan and fertility
There's no evidence to suggest that taking candesartan reduces fertility in either men or women.
Speak to a pharmacist or your doctor before taking it if you're trying to get pregnant as they will want to review your medicine with you.
Cautions with other medicines
Some medicines can affect the way candesartan works.
Tell your doctor if you're taking any of these:
- other medicines to help lower your blood pressure, including aliskiren, enalapril, captopril, lisinopril or ramipril
- painkillers such as ibuprofen, naproxen, diclofenac, celecoxib or etoricoxib
- aspirin (if you're taking more than 3g a day)
- potassium supplements or salt substitutes containing potassium
- heparin, a medicine for thinning the blood
- medicines that make you pee more (diuretics)
- lithium, a medicine for mental health problems
- spironolactone, a medicine to treat heart failure
Mixing candesartan with herbal remedies or supplements
There's very little information about taking herbal remedies and supplements with candesartan. 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.
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