Respiratory
Leukotriene receptor antagonists
Montelukast — A tablet add-on for asthma, useful where allergy or exercise is prominent.
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
What it is
Leukotriene receptor antagonists, chiefly montelukast, are oral add-on treatments for asthma and can help associated allergic rhinitis. They are an option alongside, not instead of, inhaled preventer treatment.
How it works
They block the action of leukotrienes — inflammatory chemicals released in allergic and asthmatic responses that tighten airways and drive inflammation and mucus. Blocking them reduces airway narrowing and symptoms, especially where allergy or exercise is a trigger.
In practice
In practice montelukast is a convenient once-daily tablet used as an add-on in asthma, particularly helpful where there is prominent allergic rhinitis or exercise-induced symptoms, and it offers an oral alternative for people who struggle with inhalers. It does not replace inhaled corticosteroids as the foundation of asthma control. The safety point that has come to the fore is neuropsychiatric: regulators have strengthened warnings about mood and behaviour changes — including sleep disturbance, vivid dreams, anxiety, low mood and, rarely, suicidal thoughts — so patients and parents are specifically counselled to watch for and report these, and to review whether the drug should continue if they occur. It is generally well tolerated otherwise and is taken in the evening.
Examples
Practical use
How to take it & use it well
- Take montelukast once a day, usually in the evening, as prescribed.
- It is a preventer used regularly, not a reliever, so it will not stop a sudden asthma attack - keep your reliever inhaler for that.
- Keep taking it every day even when you feel well, as the benefit comes from regular use.
- Be aware of the warning about mood and behaviour changes, and tell someone to watch for new low mood, sleep problems, agitation or unusual thoughts.
- Use it alongside your other asthma treatments as directed; do not stop your inhalers because you are taking it.
Common uses
- Add-on therapy in asthma
- Exercise-induced asthma symptoms
- Asthma with prominent allergic rhinitis
Monitoring
- Asthma control as an add-on
- Mood, sleep and behaviour (ask specifically, including in children)
- Whether to continue if neuropsychiatric effects appear
Weighing it up
Advantages & disadvantages
Advantages
- Taken as a tablet, which some people find easier than extra inhalers.
- Helps reduce asthma symptoms and can be useful when symptoms are triggered by exercise or allergies.
- Can be added on to inhaled treatment to improve control.
- May also help some people with hay fever symptoms.
Disadvantages
- Can cause neuropsychiatric effects, including low mood, vivid dreams, sleep problems, anxiety and, rarely, suicidal thoughts.
- Is an add-on or alternative and does not replace inhaled preventer treatment for most people.
- May cause headache or tummy upset.
- Does not work for everyone, so its benefit needs reviewing after starting.
Key safety principles
What to watch for
- Neuropsychiatric effects — sleep disturbance, vivid dreams, mood changes, anxiety and rarely suicidal thoughts; counsel and review if they occur.
- An add-on, not a replacement for inhaled corticosteroids in asthma.
- Generally well tolerated; taken in the evening.
Key interactions
What to avoid or check alongside
- Enzyme-inducing medicines (such as some epilepsy drugs and rifampicin): can reduce montelukast levels and effect.
- Other asthma medicines: used together as part of a treatment plan rather than as a replacement.
- Medicines affecting mood: combined effects on mental state should be monitored given the neuropsychiatric warning.
- Phenobarbital: can lower montelukast levels.
Patient & carer advice
- Keep using your inhaled preventer — this tablet is an add-on
- Report changes in mood, sleep, vivid dreams or behaviour (in yourself or your child)
- It is usually taken in the evening
Answers
Leukotriene receptor antagonists: frequently asked questions
Is montelukast a reliever for asthma attacks?
No. It is a regular preventer taken daily and does not relieve a sudden attack. Always keep your reliever inhaler for symptoms, and seek urgent help if your breathing worsens quickly.
What is the mental-health warning about montelukast?
Montelukast can cause neuropsychiatric effects such as low mood, sleep disturbance, vivid dreams, anxiety, agitation and, rarely, suicidal thoughts. Tell your clinician and stop only on advice if you or those around you notice such changes.
Why is montelukast taken in the evening?
It is usually taken at night as this fits how the medicine works and suits asthma symptom patterns for many people. Follow the timing on your prescription and take it at around the same time each day.
Can I stop my inhalers if I take montelukast?
No. For most people montelukast is added to inhaled treatment rather than replacing it. Keep using your inhalers as prescribed and review your overall plan with your clinician.
Authoritative sources
Always verify against the source
This overview is for orientation. For doses, interactions, contra-indications and the full monograph, use:
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