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  • Lowers blood pressure
  • Protects the kidneys in patients with diabetes and high blood pressure
  • Can cause dizziness
  • Not to be used while pregnant or breastfeeding

About Losartan

Losartan causes blood vessels to relax so that blood passes through them more easily, lowering blood pressure.

Losartan is used:

  • To treat high blood pressure.
  • To protect the kidneys in type 2 diabetic patients with high blood pressure.
  • In patients with high blood pressure and a thickening of the left ventricle.

How to use Losartan

Losartan should be taken with a drink of water. This medicine can be taken with or without food. Try to take the tablets at the same time each day to avoid missing any.


Dosage varies per person and is determined by a doctor depending on the symptoms. The general dosage guidelines are as follows:

  • Adults: the recommended starting dose is 50 mg once daily. In some patients the dose may later be increased to 100 mg once daily.
  • Children aged six years and above (who weigh between 20 and 50 kg): the recommended starting dose is 25 mg once daily.
  • Children aged six years and above (who weigh more than 50 kg): the recommended starting dose is 50 mg once daily.

The doctor may adjust the dose for specific patient groups, such as elderly patients or patients with liver problems. This medicine is not recommended for children under six years of age.

For more information on dosage, see the package leaflet.


Losartan is unlikely to affect your ability to drive or use machines. However, as with many other medicines used to treat high blood pressure, losartan may cause dizziness or drowsiness in some people. If you feel dizzy while taking this medicine, do not drive and do not use any tools or machines.

If you use too much/forget to use/stop using Losartan

If you have taken more Losartan tablets than you should, or if you think a child may have swallowed some, contact your doctor or pharmacist immediately.

If you accidentally miss a dose, you may take it as soon as you remember. Do not take a double dose to make up for the forgotten dose.

Do not stop using Losartan without talking to your doctor.

When not to use Losartan

Losartan is not suitable for everyone. Do not take this medicine if:

  • You are allergic to any of the other ingredients in this medicine (see section 'What Losartan contains').
  • Your liver function is severely impaired.
  • You are pregnant (see section 'Pregnancy and breastfeeding’).
  • You have diabetes or impaired kidney function and you are treated with a blood pressurelowering medicine containing aliskiren.

When should this medicine be used with caution?

Talk to your doctor or pharmacist before taking Losartan if:

  • You have a history of angioedema (swelling of the face, lip, throat, and/or tongue).
  • You suffer from excessive vomiting or diarrhoea leading to an extreme loss of fluid and/or salt from your body.
  • You take diuretics (water tablets) or are under dietary salt restrictions leading to an extreme loss of fluid and salt in your body.
  • You are known to have narrowing or blockage of the blood vessels leading to your kidneys or if you have received a kidney transplant recently.
  • Your liver function is impaired.
  • You suffer from heart failure with or without renal impairment or concomitant severe lifethreatening cardiac arrhythmias. Special caution is necessary when you are treated with a beta-blocker concomitantly.
  • You have problems with your heart valves or heart muscle.
  • You suffer from coronary heart disease or from cerebrovascular disease.
  • You suffer from primary hyperaldosteronism.
  • You are taking any of the following medicines used to treat high blood pressure: an ACEinhibitor (for example enalapril, lisinopril or ramipril, in particular if you have diabetes-related kidney problems), or aliskiren. Your doctor may check your kidney function, blood pressure, and the amount of electrolytes (e.g., potassium) in your blood at regular intervals.

Pregnancy and breastfeeding

Losartan not recommended in early pregnancy and must not be taken when more than three months pregnant, as it may cause serious harm to your baby if used after the third month of pregnancy.

Losartan is not recommended for mothers who are breastfeeding.

Other medicines and Losartan

Tell your doctor if you are taking, have recently taken or might take any other medicines. This includes medicines obtained without a prescription and herbal medicines.

Take particular care if you are taking the following medicines while under the treatment with Losartan:

  • Other blood pressurelowering medicines as they may additionally reduce your blood pressure. Blood pressure may also be lowered by one of the following drugs/class of medicines: tricyclic antidepressants, antipsychotics, baclofen, amifostin.
  • ACE inhibitors or aliskiren.
  • Medicines which retain potassium or may increase potassium levels.
  • Nonsteroidal anti-inflammatory drugs such as indomethacin, including COX-2 inhibitors (medicines that reduce inflammation, and can be used to help relieve pain).
  • Medicines containing lithium.

See the package leaflet for more information.

Side effects

Like all medicines, this medicine can cause side effects, although some people may not experience any.

If you get any of the following side effects, stop taking Losartan and tell your doctor immediately:

  • A severe allergic reaction (rash, itching, swelling of the face, lips, mouth or throat that may cause difficulty in swallowing or breathing). This is a serious, but rare side effect that may affect up to 1 in 1,000 people. You may require urgent medical care or may need to be admitted to hospital for treatment.

Other side effects of Losartan include:

Common (may affect up to 1 in 10 people):

  • Dizziness, vertigo.
  • Low blood pressure.
  • Feeling weak, fatigue.
  • Low levels of sugar in the blood (hypoglycaemia).
  • High levels of potassium in the blood (hyperkalaemia).
  • Changes in kidney function which can lead to kidney failure.
  • Reduced number of red blood cells (anaemia).
  • Increase in blood urea, serum creatinine and serum potassium in patients with heart failure.

Uncommon (may affect up to 1 in 100 people):

  • Sleepiness.
  • Headache.
  • Sleep disorders.
  • Feeling of increased heart rate (palpitations).
  • Chest tightness or pain (angina pectoris).
  • Low blood pressure, (especially after excessive loss of water from the body within blood vessels, for example in patients with severe heart failure or under treatment with highdose diuretics).
  • Doserelated orthostatic effects such as lowering of blood pressure appearing when rising from a lying or sitting position.
  • Shortage of breath.
  • Coughing.
  • Abdominal pain, constipation, diarrhoea, nausea, vomiting.
  • Nettle rash, itching, skin rash, localised swelling (oedema).

For a list of rare side effects, please see the package leaflet. If you experience side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet.

What Losartan contains

Each film-coated tablet contains 25 mg, 50 mg or 100 mg of losartan potassium.

Package leaflet

Read the package leaflet before use. The official package leaflet of Losartan is available for download here.

Reviewed by:

Dr Wouter Mol, General practitioner Registrationnumber: BIG: 9057675501 Last checked: 03-10-2023 | Still valid

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