NZ Formulary

Losartan

loe-sar-tan

What does it do?

Losartan is used to treat high blood pressure, heart failure and some kidney problems. It relaxes blood vessels, which lowers blood pressure and makes it easier for your heart to pump blood around your body.

Before you start

  • Tell your doctor if you have ever had angioedema (swollen lips, tongue, throat or face).
  • Tell your doctor if you are pregnant, planning to become pregnant, or breastfeeding.

How should you take it?

Take losartan regularly as directed with a glass of water. You can take it with or without food.

What if you forget a dose?

If it is nearly time for your next dose, skip the missed dose and take your next dose at the usual time. Otherwise, take the missed dose as soon as you remember. Do not take two doses at the same time.

Can you take other medicines?

Some medicines available without a prescription may react with losartan including:

  • anti-inflammatories, such as diclofenac (e.g. Voltaren®), ibuprofen (e.g. Nurofen®), or aspirin (e.g. Disprin®, in doses used for pain relief). These can also be found in some cold and flu medicines (e.g. Nurofen Cold and Flu®).
  • potassium supplements (e.g. Span K®)

Tell your pharmacist or doctor about all medicines or treatments that you may be taking, including vitamins, herbal products or recreational drugs.

What side effects might you notice?

Side EffectsRecommended action

Swollen lips, tongue, throat or face

Tell your doctor immediately

Changes in heartbeat, muscle cramps or weakness

Tell your doctor

Symptoms of low blood pressure such as dizziness or fainting

Stand up slowly. If it continues, or is severe, tell your doctor

If you notice any other effects, discuss them with your doctor or pharmacist.

Other information:

  • You will need regular blood tests while taking losartan to check if it is causing problems with your kidneys or the amount of potassium in your blood.