Losartan is a medicine called angiotensin receptor blocker (ARB). It's widely used to treat high blood pressure (hypertension) and heart failure. It's also used to protect your kidneys if you have both kidney disease and diabetes (diabetic kidney disease).
Losartan can also help to prevent strokes and heart attacks, and is used to improve your survival if you're taking it for heart failure or after a heart attack.
Like other ARBs, losartan relaxes and widens your blood vessels. This lowers your blood pressure and makes it easier for your heart to pump blood around your body.
Losartan can also be combined with hydrochlorothizide and is called by the brand name Cozaar-Comp.
This medicine is only available on prescription. It comes as tablets.
Key facts
- Losartan is often used as a second-choice treatment. Your doctor might prescribe it if you had to stop taking another medicine to lower your blood pressure because it gave you a dry, irritating cough.
- If you have diarrhoea and vomiting from a stomach bug or illness while taking losartan, tell your doctor. You may need to stop taking it until you feel better.
- The main side effects of losartan are feeling dizzy and tired, but they're usually mild and do not last long.
- Losartan can make you feel dizzy, especially when you first start taking it or after taking a bigger dose. If this happens, do not drive a car, ride a bike, or use tools or machinery until you feel better.
- Losartan is not normally recommended in pregnancy or while breastfeeding. Talk to your doctor if you're trying to get pregnant, are already pregnant or you're breastfeeding.
- Do not use salt substitutes such as Lo-Salt. This is because they are high in potassium and when mixed with losartan, they may cause potassium levels in your blood to be too high.