Irbesartan - an angiotensin receptor blocker Aprovel, Ifirmasta

Authored by , Reviewed by Sid Dajani | Last edited | Meets Patient’s editorial guidelines

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Take irbesartan once each day. You can take the tablets before or after meals.

Side-effects are usually mild. They include feeling dizzy and mild stomach upset.

Keep your regular appointments with your doctor to have your blood pressure measured.

Some painkillers interfere with irbesartan, so ask a pharmacist for advice before you buy any medicines.

Clinical author's note: Michael Stewart 15/11/2018: following an MHRA update, new advice has been added to this leaflet for people also taking the blood pressure medicine hydrochlorothiazide. Hydrochlorothiazide is only available in the UK in combination with other blood pressure medicines such as irbesartan. It may be available on its own in other countries. For more information see 'Getting the most from your treatment' below or view the MHRA Alert.

Type of medicineAn angiotensin-II receptor antagonist
Used forHigh blood pressure; to protect the kidneys in people with diabetes and high blood pressure
Also calledAprovel®; Ifirmasta®;
CoAprovel® (this brand contains irbesartan in combination with a medicine called hydrochlorothiazide)
Available asTablets

Irbesartan is an angiotensin receptor blocker. It is also called an angiotensin-II receptor antagonist, or an AIIRA. It is used to treat high blood pressure (hypertension). People with high blood pressure usually do not feel unwell, but if left untreated, high blood pressure can harm the heart and damage blood vessels.

Irbesartan works by blocking the effect of a chemical called angiotensin II. Angiotensin II causes your blood vessels to narrow, so by blocking its effect, irbesartan allows your blood vessels to relax and widen. As this happens, the pressure within your blood vessels is reduced. Irbesartan also has a protective function on the kidneys of people with type 2 diabetes who have high blood pressure.

Irbesartan may be prescribed on its own to treat high blood pressure, or you may also be given other medicines to take alongside it. This is because a combination of medicines which work in different ways can often lower your blood pressure more than one medicine on its own. One brand of tablet called CoAprovel® contains hydrochlorothiazide as well as irbesartan - being prescribed a combination brand like this will help to reduce the number of tablets you need to take each day.

Some medicines are not suitable for people with certain conditions, and sometimes a medicine may only be used if extra care is taken. For these reasons, before you start taking irbesartan it is important that your doctor knows:

  • If you are pregnant, trying for a baby or breastfeeding.
  • If you have a problem with your kidneys, particularly if it is a blockage of the artery which supplies blood to your kidneys.
  • If you have any problems with your heart valves or heart muscle.
  • If you are taking any other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines.
  • If you have ever had an allergic reaction to a medicine.
  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about irbesartan and will provide you with a full list of the side-effects which you may experience from taking it.
  • Take irbesartan once each day, exactly as your doctor tells you to. There are several different strengths of tablet available (75 mg, 150 mg and 300 mg) - your doctor will tell you which strength of tablet is right for you.
  • Try to take irbesartan at the same time of day each day. This will help you to remember to take your doses regularly.
  • Swallow the tablet with a drink of water. You can take irbesartan before or after meals.
  • If you forget to take a dose, take it as soon as you remember. If you do not remember until the following day, miss out the forgotten dose. Do not take two doses at the same time to make up for a forgotten dose.
  • Try to keep your regular appointments with your doctor. This is so your progress can be monitored and your blood pressure measured. Your doctor may want you to have some blood tests from time to time to check on your kidneys, and also on how much potassium is in your blood.
  • Each time you collect a prescription, check to make sure it is the strength of tablet that you are expecting.
  • If you buy any medicines, check with a pharmacist that they are suitable to take with irbesartan. This is because some anti-inflammatory painkillers (such as aspirin and ibuprofen) may interfere with the way it works, and also may increase the risk of side-effects.
  • It is very important that you follow any dietary and lifestyle advice that you may have been given by your doctor, such as eating a healthy diet, not smoking, and taking regular exercise.
  • If you drink alcohol, ask your doctor for advice. Your doctor may recommend that you do not drink alcohol while you are on irbesartan because it will increase the risk of side-effects, such as feeling dizzy or faint.
  • Try to avoid salt substitutes which contain potassium. This is because the substitutes will increase the amount of potassium in your blood and this can cause problems.
  • If you are having an operation or dental treatment, tell the person carrying out the treatment that you are taking irbesartan. This is because your blood pressure may drop too low if you are given some anaesthetics.
  • Treatment with irbesartan is usually long-term unless you experience an adverse effect. Continue to take the tablets regularly, unless you are advised otherwise by your doctor.

If you are also taking hydrochlorothiazide in combination with this medicine

  • Studies have suggested that taking higher doses of hydrochlorothiazide for long periods of time may increase the risk of certain skin cancers.
  • Tell your doctor if you have ever been treated for skin cancer before.
  • Tell your doctor about any new or changed moles or worrying marks on your skin.
  • Use a sunscreen in strong sunlight. Do not use sunbeds.

Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with irbesartan. You will find a full list in the manufacturer's information leaflet supplied with your medicine. The unwanted effects often improve as your body adjusts to the new medicine, but speak with your doctor or pharmacist if any of the following continue or become troublesome.

Common irbesartan side-effects (these affect fewer than 1 in 10 people)What can I do if I experience this?
Feeling dizzy, tired, or light-headedIf any of these become troublesome, discuss them with your doctor. Do not drive and do not use tools or machines while affected
Feeling sick (nausea) or being sick (vomiting)Stick to simple meals - avoid rich and spicy foods
Muscle and joint painAsk your pharmacist to recommend a suitable painkiller. If the pain continues, speak with your doctor
Changes to some blood testsYour doctor will check for these

Important: irbesartan has been associated with an allergic-type reaction in a few people. Although this occurs only rarely, if you get any swelling of your mouth or face, speak with your doctor or go to your local accident and emergency department straightaway.

If you experience any other symptoms which you think may be due to the tablets, speak with your doctor or pharmacist for further advice. 

  • Keep all medicines out of the reach and sight of children.
  • Store in a cool, dry place, away from direct heat and light.

Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital. Take the container with you, even if it is empty.

This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.

Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.

If you have any questions about this medicine ask your pharmacist.

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