How does montelukast work?
Montelukast is from a group of medicines called leukotriene receptor antagonists (LTRAs). LTRAs work by stopping the chemicals in your body that narrow your airways. These chemicals are called leukotrienes.
Montelukast helps stop your airways from narrowing (caused by inflammation). This makes breathing easier and prevents asthma attacks.
Leukotrienes are also released in your body when you have an allergic reaction to something like dust or pollen and when you exercise. Montelukast helps to reduce the level of leukotrienes and stops you getting symptoms.
When will I feel better?
Montelukast starts to work immediately and takes about a day to start to help asthma symptoms.
If montelukast has had no effect after you've been taking it for 4 to 8 weeks, see your doctor to talk about other treatment options.
If you're taking montelukast to prevent exercise-induced asthma, take it 2 hours before you exercise. This will mean that the level of medicine in your body is highest when you start exercising.
Are there any long-term side effects?
There's no evidence to suggest that taking montelukast will cause any problems if you take it for a long time.
Are there any other medicines for asthma?
Montelukast is one medicine used to prevent asthma symptoms.
Most people with asthma will be given an inhaler, such as beclometasone or fluticasone. Montelukast may be given as an extra medicine if your doctor thinks you need it.
Other medicines which may help prevent asthma attacks are inhalers like salmeterol or sodium cromoglicate, or medicines like theophylline.
Medicines used to relieve asthma symptoms quickly when they come on include salbutamol or terbutaline inhalers.
Will it affect my contraception?
Montelukast does not affect any type of contraception including the combined pill, progestogen-only pill or emergency contraception.
However, if montelukast makes you vomit or have severe diarrhoea for more than 24 hours, your contraceptive pills may not protect you from pregnancy. Look on the pill packet to find out what to do.
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Can I drive or ride a bike?
Montelukast does not usually cause any problems with driving or riding a bike.
However, do not drive a car or ride a bike if montelukast makes you see things which are not there (hallucinate), if you get shaking or tremors in any part of your body or you're unable to concentrate or make decisions.
It's your responsibility to decide if it's safe to drive. If you're in any doubt, do not drive.
Talk to your doctor or pharmacist if you're unsure whether it's safe for you to drive while taking montelukast. GOV.UK has more information on the law on drugs and driving.
Can I drink alcohol while taking montelukast?
Yes, you can drink alcohol while taking montelukast.
Is there any food or drink I need to avoid?
You do not need to avoid any food or drink while taking montelukast.