1. About irbesartan

Irbesartan is a medicine widely used to treat high blood pressure.

Irbesartan helps to prevent future strokes, heart attacks and kidney problems.

This medicine is only available on prescription. It comes as tablets.

2. Key facts

  • Irbesartan lowers your blood pressure and makes it easier for your heart to pump blood around your body.
  • It's often used as a second-choice treatment if you had to stop taking a similar medicine because it gave you a dry, irritating cough.
  • If you get severe vomiting or diarrhoea from a stomach bug or illness, tell your doctor. You may need to stop taking irbesartan for a while until you feel better.
  • The main side effects of irbesartan are dizziness, headache, feeling sick, vomiting and low blood pressure - but they're usually mild and short-lived.
  • Irbesartan is not normally recommended in pregnancy. Talk to your doctor if you're trying to get pregnant or you're already pregnant.
  • Irbesartan is also called by the brand name Aprovel.

3. Who can and can't take irbesartan

Irbesartan can be taken by adults aged 18 and over.

Your doctor may prescribe irbesartan if you've tried taking blood pressure-lowering medicines called angiotensin converting enzyme (ACE) inhibitors, such as ramipril and lisinopril, in the past but had to stop taking them because of side effects such as a dry, irritating cough.

Irbesartan isn't suitable for some people.

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

  • have had an allergic reaction to irbesartan or any other medicines in the past
  • have diabetes
  • have heart or kidney problems
  • have recently had a kidney transplant
  • have diarrhoea or vomiting (or if you've recently had it)
  • have been on a low salt diet
  • have low blood pressure
  • are trying to get pregnant, are already pregnant or you are breastfeeding

4. How and when to take it

Take irbesartan tablets once a day.

Your doctor may suggest that you take your first dose before bedtime, because it can make you dizzy. After the very first dose, you can take irbesartan at any time of day. Try to take it at the same time every day.

You can take irbesartan tablets with or without food. Swallow the tablets whole with a drink of water.

How much will I take?

The dose of irbesartan you take depends on why you need the medicine. Take it as instructed by your doctor.

The usual dose is 150mg to 300mg once a day.

If you are over 75, or you have liver or kidney problems, your dose may be lower.

Will my dose go up or down?

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 irbesartan.

If irbesartan doesn't bring 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 dose of irbesartan.


Take irbesartan 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 miss a dose of irbesartan, take it as soon as you remember. Do not 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?

An overdose of irbesartan can cause low blood pressure and changes in heart rate.

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

Go to A&E as soon as possible if you've taken too many irbesartan tablets

Find your nearest hospital accident and emergency (A&E) department.

Do not drive yourself - get someone else to drive you or call for an ambulance.

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

5. Side effects

Like all medicines, irbesartan 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:

  • feeling dizzy or having a spinning sensation (vertigo)
  • headache
  • feeling sick
  • vomiting or diarrhoea
  • pain in your joints or muscles

Talk to your doctor or pharmacist if these side effects bother you or don't go away.

Serious side effects

It happens rarely, but some people have serious side effects after taking irbesartan. Tell a doctor straight away if you have:

  • yellow skin or eyes - this can be a sign of liver problems
  • pale skin, feeling tired, faint or dizzy, purple spots, any sign of bleeding, sore throat and fever - these can be signs of blood or bone marrow disorder
  • 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

Serious allergic reaction

In rare cases, irbesartan may cause a serious allergic reaction.

Contact a doctor straight away 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

These are warning signs of a serious allergic reaction. A serious allergic reaction is an emergency.

These are not all the side effects of irbesartan. 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:

  • feeling dizzy - if irbesartan makes you feel dizzy when you stand up, try getting up very slowly or stay sitting down until you feel better. If you begin to feel dizzy, lie down so that you don't faint, then sit until you feel better. Don't drive or use tools or machines if you feel dizzy, have muscle cramps or muscle pain, or if you just feel a bit shaky.
  • headaches - make sure you rest and drink plenty of fluids. Don't drink too much alcohol. Ask your pharmacist to recommend a painkiller. Headaches should usually go away after the first week of taking irbesartan. Talk to your doctor if they last longer than a week or are severe.
  • feeling sick - try taking your tablets with or after a meal or snack. It may also help if you don't eat rich or spicy food.
  • vomiting or diarrhoea - drink plenty of water to prevent dehydration. If you're vomiting try small, frequent sips. Speak to a pharmacist if you have signs of dehydration, such as peeing less than usual or having dark, strong-smelling pee. If you get severe vomiting or diarrhoea from a stomach bug or illness, tell your doctor. You may need to stop taking irbesartan for a while until you feel better.
  • pain in your joints or muscles - if you get unusual muscle pain, weakness or tiredness which isn't from exercise or hard work, talk to your doctor. You may need a blood test to check what might be causing it.

7. Pregnancy and breastfeeding

Irbesartan is not normally recommended in pregnancy or when breastfeeding. However, your doctor may prescribe it if they think the benefits of the medicine outweigh the risks.

If you're trying to get pregnant or you're already pregnant, talk to your doctor about the benefits and possible harms of taking irbesartan. These will depend on how many weeks pregnant you are and the reason you need to take it. There may be other treatments that are safer for you.

Irbesartan and breastfeeding

Small amounts of irbesartan may get into breast milk. This can cause low blood pressure in the baby. Talk to your doctor, as other medicines might be better while you are breastfeeding.

Tell your doctor if you're:

  • trying to get pregnant
  • pregnant
  • breastfeeding

8. Cautions with other medicines

Some medicines interfere with the way irbesartan works.

Tell your doctor if you're taking:

  • 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 which contain potassium
  • heparin (a medicine for thinning the blood)
  • water tablets (diuretics)
  • lithium (a medicine for mental health problems)
  • spironolactone (a medicine to treat heart failure)

Mixing irbesartan with herbal remedies or supplements

There's very little information about taking herbal remedies and supplements with irbesartan.

For safety, speak to your pharmacist or doctor before taking any herbal or alternative remedies with irbesartan.


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

9. Common questions

How does irbesartan work?

Irbesartan is a type of blood pressure-lowering medicine called an angiotensin receptor blocker.

Like other angiotensin receptor blockers, irbesartan relaxes and widens your blood vessels. This lowers your blood pressure and makes it easier for your heart to pump blood around your body.

If you have diabetic kidney disease, it helps to protect your kidneys and slows down the disease. It does this by reducing the amount of protein you lose through your kidneys and by reducing high blood pressure.

How long does irbesartan take to work?

Irbesartan starts to work after about 3 to 6 hours to reduce high blood pressure but it may take up to 4 to 6 weeks for full effect.

If you have high blood pressure, you may not have any symptoms. In this case, you may not feel any different when you take irbesartan. This doesn't mean that the medicine isn't working and it's important to keep taking it.

How long will I take it for?

For high blood pressure and diabetic kidney disease, treatment with irbesartan is usually long term, even for the rest of your life.

Is it safe to take for a long time?

Irbesartan is generally safe to take for a long time. In fact, it works best when you take it for a long time.

Taking irbesartan 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.

What will happen if I stop taking it?

Talk to your doctor if you want to stop taking irbesartan.

Stopping it may cause your blood pressure to rise - and this can increase your chances of having a heart attack or stroke.

If you're bothered by side effects, your doctor may be able to prescribe you a different blood pressure-lowering medicine.

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

Even if your blood pressure is successfully lowered by irbesartan, it’s best to carry on taking it. If you stop taking irbesartan, 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 irbesartan?

Drinking alcohol can increase the blood pressure-lowering effect of irbesartan, which can make you feel dizzy or light-headed.

During the first few days of taking irbesartan or after a dose increase, it is best to stop drinking alcohol until you see how the medicine affects you.

If you find irbesartan makes you feel dizzy it's best to stop drinking alcohol.

Is there any food or drink I should avoid?

Don't use salt substitutes such as Lo-Salt. This is because they are high in potassium. When mixed with irbesartan they may make the level of potassium in your blood too high.

There's nothing else you need to avoid while taking irbesartan. Eating a healthy, balanced diet can help if you have high blood pressure.

Are there similar medicines to irbesartan?

There are several other angiotensin receptor blockers which work in the same way as irbesartan. They include candesartan, losartan and valsartan.

There are also lots of other types of blood pressure-lowering medicines such as:

  • calcium-channel blockers - for example amlodipine
  • angiotensin converting enzyme (ACE) inhibitors - for example ramipril
  • beta-blockers - for example bisoprolol
  • diuretics (water tablets) - for example bendroflumethiazide

The blood pressure-lowering medicine you're prescribed depends on your age and ethnicity:

  • if you're under 55 - you'll usually be offered an ACE inhibitor or an angiotensin receptor blocker
  • if you're aged 55 or older, or you're any age and of African or Caribbean origin - you'll usually be offered a calcium channel blocker

Many people need to take a combination of different blood pressure-lowering medicines.

What are the differences between irbesartan and other medicines for high blood pressure?

Irbesartan works as well as other angiotensin receptor blockers when it's used to lower blood pressure. Its side effects are also similar.

It also works as well as ramipril and other angiotensin converting enzyme (ACE) inhibitors to lower blood pressure.

Irbesartan can be used by people who have tried taking ramipril or other ACE inhibitors but had to give them up because they gave them a dry, irritating cough.

Can I take irbesartan before surgery?

If you're going to be put to sleep for an operation, tell your doctor that you're taking irbesartan.

Irbesartan can reduce your blood pressure when it's used with general anaesthetics (that put you to sleep).

Your doctor will probably advise you to stop taking irbesartan 24 hours before surgery.

Can I take irbesartan for migraines?

There's some evidence that irbesartan might help prevent migraines.

However, irbesartan is not officially approved for migraine. Your doctor would probably advise you to try other medicines first.

Can I take irbesartan to protect myself against Alzheimer's disease?

There have been some studies which have looked at whether blood pressure medicines could help protect people against Alzheimer's. However, at the moment, there is not enough evidence to recommend taking irbesartan or other similar medicines for Alzheimer's.

There are steps you can take that may reduce your risk of Alzheimer's. If you are worried about getting Alzheimer's disease in the future or have a family history of this condition, speak to your doctor.

Is irbesartan addictive?

No, there's no evidence that irbesartan is addictive.

Will it affect my sex life?

Irbesartan won't affect your sex life.

Will it affect my fertility?

There's no evidence that irbesartan reduces fertility in men or women. However, if you are a woman and you are trying to get pregnant, talk to your doctor first as this medicine is usually not recommended in pregnancy.

Will it affect my contraception?

Irbesartan won't affect any type of contraception.

However, some types of hormonal methods of contraception, like the combined contraceptive pill and contraceptive patch, aren't usually recommended for women taking irbesartan and other medicines for high blood pressure. This is because some hormonal contraceptives can raise your blood pressure and stop irbesartan working properly.

Talk to your doctor if you're taking combined hormonal contraceptives.

Can I drive or ride a bike?

Irbesartan can make some people feel dizzy - especially when you first start taking it or after taking a bigger dose. If this happens to you, don't drive a car, ride a bike, or use tools or machinery.

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.

  • Stop smoking - smoking increases your heart rate and blood pressure. Quitting smoking brings down your blood pressure and relieves heart failure symptoms. Try and avoid secondhand smoke.
  • Drink alcohol sensibly - drinking too much alcohol raises blood pressure over time. It makes heart failure worse too. Men and women shouldn't drink more than 14 units of alcohol a week.
  • Be more active - 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 healthily - 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.
  • Manage 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.

Page last reviewed: 14/08/2017
Next review due: 14/08/2020