Always take losartan exactly as your doctor has told you, and follow the directions on the label. If you're not sure, check with your doctor or pharmacist.
Dosage and strength
Your dose of losartan depends on why you need the medicine.
Losartan comes as 12.5mg, 25mg, 50mg and 100mg tablets.
The usual dose for adults is:
- 50mg to 100mg, taken once a day to treat high blood pressure or protect your kidneys
- 12.5mg to 150mg, taken once a day for heart failure
- 25mg, taken once a day by over 75s to protect kidneys
The dose may be lower if you've recently had diarrhoea or been sick (vomiting), or you are over the age of 75.
If your child needs losartan, their doctor will usually use your child's weight to work out the right dose.
Changes to your dose
After a few weeks your doctor will check your blood pressure and ask if you're getting any side effects. You may also need blood tests to check how well your kidneys are working and the amount of potassium in your blood. Your doctor will then decide whether to change your dose of losartan.
If losartan does not bring your blood pressure down, your doctor may want to increase your dose. If your blood pressure gets too low or you get side effects, your doctor may lower your dose.
Important
Take losartan even if you feel well, as you will still be getting the benefits of the medicine.
How to take it
Take losartan tablets once a day.
Your doctor may suggest that you take your first dose before bedtime, because it can make you feel dizzy. After your first dose, you can take losartan at any time of day. But try to take it at the same time every day.
You can take losartan tablets with or without food. Swallow the tablet whole with a drink of water.
How long to take it for
Usually, treatment with losartan is long term, and you may have to take it for the rest of your life.
If you get sick while taking it
If you have severe diarrhoea or are being sick (vomiting) for any reason, contact your doctor or a pharmacist. They'll be able to advise you about what to do. They may recommend that you stop taking losartan until you're better, and you can eat and drink normally again.
If you take contraceptive pills and you're being sick or have severe diarrhoea, your contraception may not protect you from pregnancy. Check the pill packet for advice.
If you forget to take it
If you miss a dose of losartan, take it as soon as you remember. If you do not remember until the next day, leave out the missed dose and carry on as normal.
Do not take 2 doses to make up for a forgotten one.
If you often forget doses, it may help to set an alarm to remind you. You could also ask your pharmacist for advice on other ways to help you remember to take your medicine.
Stopping losartan
Stopping losartan may cause your blood pressure to rise, and this can increase your chances of having a heart attack or stroke.
If you're bothered by side effects, your doctor may be able to prescribe you a different blood pressure-lowering medicine.
If you take too much
The amount of losartan that can lead to an overdose varies from person to person.
An overdose of losartan can cause dizziness, sleepiness and a pounding heartbeat (palpitations).
Urgent advice: Contact 111 for advice now if:
- you take more than your prescribed dose of losartan
Go to 111.nhs.uk or call 111
If you need to go to A&E, do not drive yourself. Get someone else to drive you or call for an ambulance.
Take the losartan packet or leaflet inside it plus any remaining medicine with you.