Montelukast and zafirlukast are oral anti-asthma drugs that block leukotriene-mediated inflammation. They are widely used in asthma and allergic rhinitis, especially when inhalers are not enough or adherence is poor.
What Are Montelukast and Zafirlukast?
Both drugs belong to the class leukotriene receptor antagonists (LTRAs).
Montelukast
- Brand name: Singulair
- Most commonly prescribed LTRA worldwide
Zafirlukast
- Brand name: Accolate
- Older alternative, used less often today
They are controller medications, not rescue drugs.
Related Core Entities
1. AsthmaMechanism of Action
In asthma, leukotrienes (LTC₄, LTD₄, LTE₄) cause:
- Bronchoconstriction
- Mucus secretion
- Airway edema
- Eosinophilic inflammation
Montelukast & Zafirlukast:
- Block CysLT₁ receptors
- Prevent leukotrienes from binding
- Reduce airway inflammation and bronchospasm
Result: Better asthma control and fewer night/exercise symptoms
Clinical Uses
Montelukast Uses
- Mild to moderate chronic asthma (add-on therapy)
- Allergic rhinitis (seasonal & perennial)
- Exercise-induced bronchoconstriction
- Aspirin-exacerbated respiratory disease (AERD)
Zafirlukast Uses
- Chronic asthma (alternative to montelukast)
- Aspirin-sensitive asthma
Not for acute asthma attacks
Dosage
Montelukast Dose
| Age | Dose |
|---|---|
| Adults & ≥15 yrs | 10 mg once daily (evening) |
| 6–14 yrs | 5 mg once daily |
| 2–5 yrs | 4 mg once daily |
Zafirlukast Dose
| Group | Dose |
|---|---|
| Adults | 20 mg twice daily |
| Children <5 yrs | Not recommended |
Onset: Within days
Full benefit: 2–4 weeks
How to Take These Drugs
1. Take regularly, even when asymptomaticSide Effects
Common (Both)
- Headache
- Abdominal pain
- Upper respiratory symptoms
Neuropsychiatric Effects
- Sleep disturbances
- Anxiety, irritability
- Depression, suicidal thoughts (rare but serious)
FDA boxed warning
Use montelukast for allergic rhinitis only when alternatives fail.
Zafirlukast-Specific
- Hepatotoxicity
- Elevated liver enzymes
- Rare hepatic failure
Contraindications & Warnings
1. History of neuropsychiatric illness → caution with montelukastMontelukast vs Zafirlukast
| Feature | Montelukast | Zafirlukast |
|---|---|---|
| Dosing | Once daily | Twice daily |
| Food interaction | None | Yes |
| Liver toxicity | Rare | More common |
| Neuropsychiatric risk | Yes | Minimal |
| Current use | Very common | Limited |
Clinical preference: Montelukast remains first choice.
Common Mistakes
❌ Using for acute asthma attack
✅ Use short-acting β₂ agonist
❌ Stopping inhaled steroids
✅ LTRAs are add-on, not replacement
❌ Ignoring mood changes
✅ Stop drug and reassess immediately
❌ Irregular dosing
✅ Daily adherence is critical
FAQs
Is montelukast a steroid?
No. It is a leukotriene receptor antagonist.
Can montelukast replace inhalers?
No. It complements inhaled therapy.
Why is montelukast taken at night?
Leukotriene activity peaks at night.
Is zafirlukast better than montelukast?
No. It has more interactions and liver risk.
Can children take montelukast?
Yes, in age-appropriate doses.
