Belair is montelukast, in 4 mg and 5 mg chewable tablets and a 10 mg tablet. It is used for asthma prevention and allergic rhinitis. It is a preventer taken every day, not a reliever — and it carries a mental health warning that every person taking it should know about.
What is Belair?
The South African Medicine Price Registry lists Belair as Schedule 3 containing montelukast sodium:
| Form | Strength | Typical age |
|---|---|---|
| Chewable | 4 mg | 2–5 years |
| Chewable | 5 mg | 6–14 years |
| Tablet | 10 mg | 15 years and over |
The strengths map to age, not severity. Moving a child from 4 mg to 5 mg usually means they have had a birthday, not that their asthma has worsened.
Montelukast is a leukotriene receptor antagonist. Leukotrienes are inflammatory chemicals released during an allergic response; they narrow the airways, increase mucus, and draw inflammatory cells into the lining of the lungs and nose. Montelukast blocks the receptor they act on.
Three things follow from that, and all are commonly misunderstood.
It is a preventer, not a reliever. It does nothing for an asthma attack in progress. A reliever inhaler — usually salbutamol — is what treats an attack, and montelukast never replaces one.
It must be taken every day, whether or not you have symptoms. Taken only on bad days it does very little.
It takes days to work, with the full effect over a few weeks.
Why it is chosen. Inhaled corticosteroids remain the mainstay of asthma prevention and are more effective for most people. Montelukast is a tablet rather than an inhaler, which is a real advantage for young children and for anyone who cannot use an inhaler properly, and it treats the nose and the chest together — useful, since allergic rhinitis makes asthma harder to control. It is also particularly effective in exercise-induced asthma and in asthma triggered by aspirin or anti-inflammatories.
What is Belair commonly used for?
- Preventing asthma symptoms in adults and children from two years, usually alongside an inhaled steroid rather than instead of one.
- Exercise-induced bronchoconstriction, where it works particularly well.
- Allergic rhinitis — seasonal hay fever and year-round allergic rhinitis — treating the nose and chest with one tablet.
- Aspirin-sensitive asthma, where leukotrienes play a large role.
- Mild persistent asthma, as an alternative where an inhaled steroid cannot be used.
- Reducing the need for reliever inhaler use.
It does not treat an attack. If you are wheezing, breathless or tight-chested now, use your reliever inhaler and seek help if it does not settle.
Asthma control is judged by specific things, not by how you feel on a good day: needing your reliever more than twice a week, waking at night with symptoms, or symptoms limiting activity all mean control is inadequate and the treatment needs reviewing.
Inhaler technique matters more than most people realise. A large proportion of people use their inhaler incorrectly, and poor technique is a commoner reason for poor control than the wrong medicine. Ask a pharmacist to watch you use it — this takes two minutes and is genuinely worth it.
How Belair fits into this medicine category
| Group | Examples | Role |
|---|---|---|
| Leukotriene antagonists | Montelukast (Belair) | Preventer tablet; nose and chest |
| Inhaled corticosteroids | Budesonide, fluticasone | Mainstay asthma preventer |
| Reliever inhalers | Salbutamol | Treats an attack |
| Long-acting bronchodilators | Formoterol, salmeterol | With a steroid, never alone |
| Antihistamines | Cetirizine, Rhineton | Allergic rhinitis; not asthma |
| Nasal steroids | Fluticasone, mometasone | Most effective for nasal congestion |
See the allergy, cold and flu medicines hub.
What to check before using Belair
The most important thing to know about montelukast is its mental health warning.
Regulators in several countries, including the US FDA, have issued strengthened warnings — a boxed warning in the United States — about neuropsychiatric events: agitation, aggression, anxiety, depression, sleep disturbance, vivid dreams and nightmares, hallucinations, and in rare cases suicidal thoughts and behaviour. These have been reported in adults and children, sometimes within days of starting, and sometimes after months of uneventful use.
They are uncommon, and most people take montelukast without any such problem. But they are real, they are reversible on stopping, and they are frequently not connected to the medicine — a child becoming irritable, anxious or sleepless, or an adult becoming low, is easily attributed to something else.
If you or your child are taking Belair, know this in advance and watch for it. Tell your doctor promptly about any change in mood, behaviour or sleep. This is worth mentioning to anyone else who looks after the child.
Also tell your doctor or pharmacist if you:
- Have a history of depression, anxiety or other mental health conditions.
- Have liver disease.
- Have phenylketonuria — the chewable tablets contain aspartame.
- Are pregnant or breastfeeding.
- Have severe asthma or have needed oral steroids.
Practical points:
- Take it once daily in the evening. For allergic rhinitis alone, any consistent time works.
- Take it every day, symptoms or not.
- Keep using your inhalers. Montelukast does not replace an inhaled steroid or a reliever, and stopping either is dangerous.
- Chewable tablets are chewed, not swallowed whole.
- Have a written asthma action plan, and know when to seek help.
- Do not stop other asthma medicines without advice.
Possible cautions and when to ask a pharmacist or doctor
Common effects: headache, abdominal pain, thirst, sleep disturbance and vivid dreams.
Contact your doctor promptly for any of the following, and mention the medicine specifically:
- New or worsening depression, anxiety or agitation.
- Irritability, aggression, restlessness or unusual behaviour, particularly in a child.
- Nightmares, sleepwalking, insomnia or hallucinations.
- Tremor, or a pins-and-needles sensation.
- Any thoughts of self-harm. Seek help immediately — a doctor, an emergency department, or the South African Depression and Anxiety Group.
Get emergency help for:
- An asthma attack not responding to your reliever inhaler, difficulty speaking in full sentences, blue lips, or exhaustion from the effort of breathing.
- Swelling of the face, lips or tongue, or difficulty breathing.
- A widespread rash with fever, or a rash of small purple spots, particularly with numbness, weakness or worsening breathlessness — a rare condition called eosinophilic granulomatosis with polyangiitis has been reported, usually as oral steroids are being reduced.
Seek advice for:
- Asthma not improving after a few weeks.
- Using your reliever more than twice a week, waking at night, or symptoms limiting activity — all indicate inadequate control.
- A rash or itching.
- Yellowing of the skin or eyes.
See a doctor if asthma symptoms are worsening, if you have needed a course of oral steroids, if you are unsure of your inhaler technique, or if you do not have an action plan. Ask specifically about the mental health effects if you notice any change — it is a question doctors expect and take seriously.
Related medicine guides
- Browse Allergy, Cold & Flu Medicines guides
- Read: Austell Cetirizine used for
- Read: Rhineton used for
Frequently asked questions
What is Belair 10 mg used for? Preventing asthma symptoms and treating allergic rhinitis in adults and children from 15 years. It contains montelukast.
What are the 4 mg and 5 mg chewables for? The same conditions in children — 4 mg for ages two to five, 5 mg for six to fourteen. The strengths map to age, not severity.
Is it a reliever inhaler substitute? No. It does nothing for an attack in progress. Always keep and use your reliever inhaler.
When should I take it? Once daily in the evening for asthma. Every day, whether or not you have symptoms.
How long before it works? Days for initial effect, with the full benefit over a few weeks.
Does it have mental health side effects? It can. Regulators have warned about agitation, aggression, anxiety, depression, nightmares, sleep disturbance and rarely suicidal thoughts. They are uncommon and reversible on stopping — but tell your doctor promptly about any change in mood, behaviour or sleep.
Can it replace my inhaled steroid? Usually not. Inhaled steroids remain the mainstay of asthma prevention. Do not stop yours without advice.
Can children take it? Yes, from two years, using the age-appropriate chewable. Watch for behaviour and sleep changes and report them.