Losartan
Also known as: Cozaar
What it's for
Losartan lowers high blood pressure and protects your kidneys if you have diabetes. It is an alternative if you get a cough with ACE inhibitors like ramipril or lisinopril.
Comes as: Tablets
How to take it
- Adults: Usually 50mg once a day, increased to 100mg if needed.
- Take at the same time each day.
- You can take it with or without food.
- It may take a few weeks to work fully.
Doses here are typical. Always follow the instructions from your prescriber or on the packet — they come first.
Common side effects
- Feeling dizzy, especially when standing up
- Headache
- Feeling tired
- Raised potassium levels (usually no symptoms)
The leaflet inside the packet lists all known side effects.
Important safety points
- Not suitable during pregnancy
- Avoid potassium supplements and salt substitutes
- Tell your doctor if you have liver or kidney problems
- May make you feel dizzy - take care when driving
Get medical help urgently if…
- You have swelling of your face, lips, or throat
- You have difficulty breathing
- You have severe dizziness or fainting
- You have muscle weakness or an irregular heartbeat
Call NHS 111 for urgent advice, or 999 if someone is seriously unwell.
Before you act on anything here
This page is general information, written to help you understand — it is not personal medical advice and it cannot tell you what is right for you. Talk to your own GP, pharmacist or nurse about your own health.
- Need help now but it's not an emergency? Call NHS 111 or use 111.nhs.uk.
- Emergency? Call 999 or go to A&E.