Candesartan (Amias)

How does it work?

Amias tablets contain the active ingredient candesartan, which is a type of medicine called an angiotensin II antagonist. It works by preventing the action of a hormone in the body called angiotensin II.

Angiotensin II normally acts on special receptors in the body, with two main results. Firstly, it causes the peripheral blood vessels to narrow, and secondly, it stimulates the production of another hormone called aldosterone. Aldosterone causes salt and water to be retained by the kidneys, which increases the volume of fluid in the blood vessels.

Candesartan blocks the receptors that angiotensin II acts on and so prevents its actions. The main result of this is that the peripheral blood vessels are allowed to widen, which means that there is more space and less resistance in these blood vessels. This lowers the pressure inside the blood vessels.

Blocking the actions of angiotensin II also reduces the action of aldosterone on the kidneys. The result of this is an increase in the amount of fluid removed from the blood by the kidneys. This decreases the amount of fluid in the blood vessels, which also lessens the resistance and pressure in the blood vessels.

The combined overall effect of these changes is to lower the blood pressure.

Candesartan is also used to improve the symptoms of heart failure, where the heart is not pumping as efficiently as it should. It helps heart failure because lowering the pressure within the blood vessels means that the heart doesn't have to work as hard to pump the blood around the body.

What is it used for?

  • High blood pressure with no known cause (essential hypertension).
  • Heart failure.

How do I take it?

  • Amias tablets can be taken either with or without food. The tablet should be swallowed with a drink of water.
  • The dose prescribed and how often the medicine needs to be taken depends on the condition being treated. Amias tablets are usually taken once daily. It is important to follow the instructions given by your doctor. These will be printed on the dispensing label your pharmacist has put on the packet of medicine.
  • It is important that you don't suddenly stop taking this medicine unless your doctor tells you to.


  • Dizziness and weariness may occasionally occur during treatment with blood pressure lowering medicines. If you are affected, it is important that you take extra care when driving or operating machinery.
  • You should take extra care if you drink alcohol while taking this medicine, as it may enhance the blood pressure lowering effect and could make you feel dizzy or faint.
  • People with heart failure or decreased kidney function should have regular blood tests to monitor the levels of potassium and creatinine in their blood while taking this medicine.
  • People with high blood pressure caused by high levels of the hormone aldosterone (primary hyperaldosteronism) do not generally respond to this type of blood pressure lowering medicine, and it is not recommended for these people.
  • The safety and efficacy of this medicine in children under 18 years of age has not been studied by the manufacturer.

Use with caution in

  • People with a decreased fluid volume in the body, eg due to diuretic therapy, low salt diet, kidney dialysis, diarrhoea, vomiting, dehydration.
  • Decreased kidney function or kidney disease.
  • People who have narrowing in the arteries that supply blood to the kidneys (renal artery stenosis).
  • Decreased liver function.
  • Disease of the blood vessels in and around the brain (cerebrovascular disease).
  • Heart disease caused by inadequate blood flow to the heart (ischaemic heart disease).
  • Heart disease characterised by thickening of the internal heart muscle and a blockage inside the heart (hypertrophic obstructive cardiomyopathy).
  • Heart valve disease (mitral valve stenosis).
  • Narrowing of the main artery of the body (aortic stenosis).
  • Severe heart failure.

Not to be used in

  • Pregnancy.
  • Breastfeeding.
  • Severely decreased liver function.
  • Conditions where bile cannot flow from the liver to the intestines ((cholestasis) – this often causes jaundice).
  • Rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (Amias tablets contain lactose).
  • The safety and efficacy of this medicine in children under 18 years of age has not been studied by the manufacturer. It is not recommended for children.

This medicine should not be used if you are allergic to any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

  • This medicine should not be used during pregnancy as it may be harmful to an unborn baby. Seek medical advice from your doctor. Women who could get pregnant should use effective contraception to prevent pregnancy during treatment. If you do fall pregnant stop taking this medicine and consult your doctor immediately.
  • It is not known if this medicine passes into breast milk. However, it could have adverse effects on a nursing infant if it does and the manufacturer states that it should not be used by breastfeeding mothers. Seek medical advice from your doctor.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here, it does not mean that all people using this medicine will experience that or any side effect.

Common (affect between 1 in 10 and 1 in 100 people)

  • Dizziness.
  • Spinning sensation.
  • Headache.
  • Chest infections.
  • Low blood pressure in people taking this medicine for heart failure.
  • Increased amount of potassium in the blood (hyperkalaemia).
  • Decreased kidney function.

Very rare (affect less than 1 in 10,000 people)

  • Cough.
  • Nausea.
  • Elevation in liver enzymes.
  • Inflammation of the liver (hepatitis).
  • Skin reactions such as rash, hives (urticaria), redness or itching.
  • Severe swelling of lips, face, tongue or throat (angioedema).
  • Back pain.
  • Pain in the muscles or joints.
  • Kidney failure.
  • Decrease in the number of white blood cells in the blood (leukopenia and neutropenia).
  • Decreased level of sodium in the blood (hyponatraemia).

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to ensure that the combination is safe.

This medicine is likely to have an additive effect with other medicines that decrease blood pressure, particularly medicines that are used to treat high blood pressure (antihypertensives). This may cause dizziness, which can usually be relieved by lying down until the symptoms pass. If you feel dizzy while taking this medicine in combination with other medicines that can lower blood pressure you should let your doctor know, as your doses may need adjusting. Other medicines that decrease blood pressure include the following:

  • ACE inhibitors, eg enalapril
  • aldesleukin
  • alpha-blockers such as prazosin
  • alprostadil
  • other angiotensin II receptor antagonists such as losartan
  • antipsychotics such as chlorpromazine
  • benzodiazepines, eg temazepam, diazepam
  • baclofen
  • other beta-blockers such as propranolol
  • calcium channel blockers such as felodipine.
  • clonidine
  • diazoxide
  • diuretics, eg furosemide, bendroflumethiazide
  • dopamine agonists, eg bromocriptine, apomorphine
  • hydralazine
  • levodopa
  • MAOI antidepressants, eg phenelzine
  • methyldopa
  • minoxidil
  • moxonidine
  • moxisylyte
  • nicorandil
  • nitrates, eg glyceryl trinitrate
  • tizanidine.

Candesartan may increase the level of potassium in your blood. If this medicine is taken with other medicines that can increase blood potassium levels, this effect may be enhanced. Your doctor may want to monitor your blood potassium levels if you take any of these medicines with candesartan:

  • ACE inhibitors, eg enalapril
  • other angiotensin II receptor antagonists, eg losartan
  • ciclosporin
  • drospirenone
  • heparin
  • non-steroidal anti-inflammatory drugs, eg indometacin, diclofenac, ibuprofen
  • potassium-sparing diuretics eg spironolactone, triamterene, amiloride
  • potassium supplements
  • potassium salts, eg potassium citrate for cystitis.
  • potassium-containing salt substitutes such as Lo-Salt.
  • tacrolimus.

Non-steroidal anti-inflammatory drugs (NSAIDs, eg indometacin, aspirin, diclofenac, ibuprofen) may reduce the blood pressure lowering effect of candesartan, and may also increase the risk of a decline in kidney function. You should avoid taking this type of painkiller unless recommended by your doctor.

Candesartan may increase the blood level of the medicine lithium, and the combination is not recommended. If it is necessary to take both lithium and candesartan, your doctor should carefully monitor your blood level of lithium. You should let your doctor know if you experience any signs that your lithium level is increasing, for example, loss of appetite, diarrhoea, vomiting, blurred vision, muscle weakness, lack of co-ordination, drowsiness, tremor, unsteadiness, muscle twitching, ringing in the ears or confusion.

The following medicines may reduce the blood pressure lowering effect of this medicine:

  • corticosteroids, such as dexamethasone or prednisolone
  • oestrogens, such as those in the contraceptive pill.

Other medicines containing the same active ingredient

There are currently no other medicines available in the UK that contain candesartan as the active ingredient.