Montelukast
Also known as: Singulair
What it's for
Montelukast helps prevent asthma attacks and relieve allergies. It reduces swelling in your airways. It is not a reliever inhaler and will not help sudden breathing problems.
Comes as: Tablets or granules
How to take it
- Adults: Usually 10mg once a day in the evening.
- Take at the same time each day.
- You can take it with or without food.
- Keep using your preventer inhaler as well.
Doses here are typical. Always follow the instructions from your prescriber or on the packet — they come first.
Common side effects
- Headache
- Stomach pain or diarrhoea
- Feeling thirsty
- Sleep problems
The leaflet inside the packet lists all known side effects.
Important safety points
- Does not relieve sudden asthma attacks - use your blue inhaler for that
- Rarely causes mood changes or depression - tell your doctor if you notice this
- Tell your doctor about all medicines you take
Get medical help urgently if…
- You have thoughts of harming yourself or feel depressed
- You have severe mood or behaviour changes
- You have a severe allergic reaction
- Your asthma symptoms get worse
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.