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Losartan - an angiotensin receptor blocker

Cozaar

Take losartan once each day. You can take your doses either before or after a meal.

Any side-effects are usually mild, and can include feeling dizzy or light-headed.

Some painkillers can interfere with losartan and increase the risk of side-effects, so ask a pharmacist for advice before you buy any medicines 'over the counter'.

Do not drink grapefruit juice whilst taking losartan. It can interact with the medicine and alter its effect.

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 medicines used to treat high blood pressure. It may be available on its own in other countries. For more information see the warning below in 'can this medicine cause problems?' or view the MHRA Alert.

At a glance

  • Losartan is a medicine often prescribed for high blood pressure, heart failure, or kidney disease linked to diabetes.

  • It works by blocking a substance in your body called angiotensin II, which helps lower blood pressure.

  • Take losartan once a day, at the same time each day, with or without food.

  • Tell your doctor if you are pregnant, breastfeeding, or have kidney, heart, or liver problems.

  • Common side effects can include feeling tired or dizzy when standing up.

  • Avoid certain anti-inflammatory painkillers and salt substitutes while taking this medicine.

  • If you are taking losartan with hydrochlorothiazide, protect your skin from the sun.

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About losartan

Typ av medicin

An angiotensin-II receptor antagonist

Används för

High blood pressure; heart failure; kidney disease associated with diabetes

Även kallad

Cozaar®;
Combination brand: Cozaar-Comp® (losartan with hydrochlorothiazide)

Tillgänglig som

Tabletter

Losartan is an angiotensin receptor blocker. It is also called an angiotensin-II receptor antagonist, or an AIIRA. You will have been prescribed losartan for one of the following reasons:

Losartan works by blocking the effect of a substance in your body called angiotensin II. Angiotensin II causes your blood vessels to narrow and also leads to the production of another substance called aldosterone, which increases the amount of fluid in your blood. By preventing the action of angiotensin II, losartan reduces how much work your heart has to do and lowers your blood pressure. It also has a protective effect on your kidneys.

You may be prescribed losartan to take on its own, or alongside other medicines to help your condition. There is a combination tablet available called Cozaar-Comp® which contains losartan with a diuretic called hydrochlorothiazide. This combination tablet can be prescribed to people with high blood pressure to help reduce the total number of tablets that need to be taken each day.

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

  • Om du är gravid eller ammar.

  • If you know you have a blockage of the artery which supplies blood to your kidneys, a condition called renal artery stenosis.

  • If you have any problems with your heart valves or heart muscle.

  • If you have a problem with the way your liver works.

  • Om du tar några andra läkemedel. Detta inkluderar alla läkemedel du tar som finns att köpa utan recept, samt växtbaserade och komplementära läkemedel.

  • If you have ever had an allergic reaction to a medicine, or if you have had any other type of allergic reaction.

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  • Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about losartan and will provide you with a full list of the side-effects which you could experience from taking it.

  • Take losartan once each day, exactly as your doctor tells you to. There are several different strengths of tablet available. When you first start treatment your doctor may gradually increase the strength of the tablets to suit your condition. Each time you collect a fresh supply, it's a good idea to check the strength on the packet to make sure they are what you are expecting.

  • Try to take losartan at the same time of day each day. For most people this will be in the morning. Taking your doses at the same time each day will help you to remember to take losartan regularly.

  • Swallow the tablet whole with a drink of water. You can take losartan either before or after a meal.

  • 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. Your doctor may want you to have some blood tests from time to time to check on your kidneys, and also how much potassium is in your blood.

  • If you buy any medicines, check with a pharmacist that they are suitable to take with losartan. This is because some anti-inflammatory painkillers (such as aspirin and ibuprofen) can 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 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 losartan 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 losartan. This is because your blood pressure may drop too low if you are given some anaesthetics.

  • Treatment with losartan is usually long-term unless you experience an adverse effect. Continue to take the tablets regularly, unless you are advised otherwise by your doctor.

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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 losartan. 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 losartan side-effects (these affect fewer than 1 in 10 people)

Vad kan jag göra om jag upplever detta?

Feeling tired, or dizzy and light-headed when you stand up (due to low blood pressure)

Getting up and moving more slowly should help. If you begin to feel dizzy, sit for a few minutes before you stand up again

Changes in the amount of potassium in your blood

You will have blood tests from time to time to check for this

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.

Om du upplever några andra symtom som du tror kan bero på medicinen, tala med din läkare eller apotekare för vidare råd.

  • Förvara alla läkemedel utom räckhåll och synhåll för barn.

  • Store the tablets in a cool, dry place, away from direct heat and light.

Viktig information om alla läkemedel

Ta aldrig mer än den föreskrivna dosen. Om du misstänker att du eller någon annan kan ha tagit en överdos av denna medicin, gå omedelbart till akutmottagningen på ditt lokala sjukhus. Ta med behållaren, även om den är tom.

Denna medicin är för dig. Ge den aldrig till andra människor även om deras tillstånd verkar vara detsamma som ditt.

Behåll inte föråldrade eller oönskade mediciner. Ta dem till ditt lokala apotek som kommer att ta hand om dem åt dig.

Om du har några frågor om denna medicin, fråga din apotekare.

Rapportera biverkningar av ett läkemedel eller vaccin

Om du upplever biverkningar kan du rapportera dem online via Yellow Card website.

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Vanliga frågor

How does losartan actually help my heart if it's not beating well?

Losartan works by blocking the effects of a substance in your body called angiotensin II. Angiotensin II narrows your blood vessels and also increases the amount of fluid in your blood by triggering the production of aldosterone. By preventing angiotensin II from acting, losartan reduces the effort your heart has to make, which helps if your heart isn't beating as effectively as it should.

Can I switch the time of day I take my losartan if my routine changes?

It is recommended to take losartan at the same time each day to help you remember to take it regularly. While for most people this is in the morning, the article doesn't specify if changing the time is problematic, but it does say if you forget a dose, take it as soon as you remember, unless it's nearly the next day. Consistency is the key.

Is it safe to use salt substitutes if I'm trying to reduce my salt intake while on losartan?

No, you should try to avoid salt substitutes that contain potassium. Losartan can affect the amount of potassium in your blood, and these substitutes would further increase potassium levels, which could lead to problems.

What should I do if I notice any new skin changes, especially if I'm taking the combination tablet?

If you are taking losartan in combination with hydrochlorothiazide, you should tell your doctor about any new or changed moles or worrying marks on your skin. Studies suggest that higher doses of hydrochlorothiazide over long periods may increase the risk of certain skin cancers. It's also important to use sunscreen in strong sunlight and avoid sunbeds.

How long will I need to take losartan?

Treatment with losartan is usually considered long-term. You should continue to take the tablets regularly unless your doctor advises you otherwise, for example, if you experience an adverse effect.

If I feel dizzy when I stand up after taking losartan, what should I do?

If you experience dizziness or light-headedness when you stand up, which can happen due to low blood pressure, try getting up and moving more slowly. If you start to feel dizzy, sit for a few minutes before you attempt to stand up again.

Vidare läsning och referenser

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About the authorView full bio

Author image

Michael Stewart, MRPharmS

Medicine Leaflet Review Manager – Contractor, Pharmacist

BPharm (Hons), MRPharmS

Michael is a community pharmacist practicing in the Midlands and South Yorkshire with more than 20 years’ experience advising on medicines and medical conditions. He has a strong background in healthcare training, having produced and delivered training courses for pharmacy teams and staff of residential care settings, including nurses. He has also contributed to pharmacy advisory boards for the management of low acuity conditions in the community.

About the reviewer

Author image

Sid Dajani

Sultan Dajani qualified at the London School of Pharmacy in 1994 and became the youngest elected member of the Royal Pharmaceutical Society council since its founding in 1842.

Artikelhistorik

Informationen på denna sida är skriven och granskad av kvalificerade kliniker.

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