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This is an information resource — not medical advice.

PillCodex provides general educational information about medications. This content is not a substitute for professional medical advice, diagnosis, or treatment. Never start, stop, or change a medication based on what you read here. Always speak to your doctor, pharmacist, or qualified healthcare provider with questions about your medications.

🚨 If you are experiencing a medical emergency or think you may have taken too much of a medication, call emergency services (911 in the US) or go to your nearest emergency room immediately.

Leukotriene Receptor Antagonist🔒 Prescription only

What Is Montelukast (Singulair) Used For?

Brand names: Singulair

Montelukast prevents asthma attacks and relieves seasonal allergy symptoms. It has an important FDA black box warning about neuropsychiatric side effects.

What is Montelukast used for?

Prevention of asthma attacks
Seasonal allergic rhinitis (hay fever)
Year-round allergies
Exercise-induced bronchospasm prevention

How does Montelukast work?

Montelukast blocks leukotriene receptors. Leukotrienes are inflammatory chemicals released during allergic reactions that cause airway swelling, mucus production, and bronchoconstriction.

Dosage information

💊Available forms

4mg chewable tablets (children 2–5)
5mg chewable tablets (children 6–14)
10mg tablets (adults)
4mg oral granules (infants 12+ months)

📏Typical dosage

Adults: 10mg once daily in the evening. Children have lower age-appropriate doses.

⚠️ Dosage varies by individual. Always follow your doctor's or pharmacist's instructions — never self-dose based on general information.

Side effects

Common

Headache
Stomach pain
Heartburn
Fatigue
Ear infection in children

⚠️ Serious — contact your doctor

Neuropsychiatric events (BLACK BOX WARNING) — agitation, aggression, depression, suicidal thoughts, sleep disorders, hallucinations

Important warnings

BLACK BOX WARNING: serious mental health side effects including suicidal thinking — monitor closely and report mood/behavior changes immediately

Not a rescue medication — does not treat acute asthma attacks

Reconsider for allergies alone given psychiatric risk

Take in the evening for asthma prevention

Drug interactions

These substances may interact with Montelukast. This is not a complete list — always tell your doctor and pharmacist ALL medications and supplements you take.

Gemfibrozil (increases levels)Rifampin (reduces effectiveness)PhenobarbitalPhenytoin

Pregnancy & breastfeeding

🤰 Use with caution — discuss with your doctor

Always consult your doctor or obstetrician before taking any medication during pregnancy or while breastfeeding.

Frequently asked questions

What is montelukast (Singulair) used for?

Montelukast prevents asthma attacks and relieves seasonal and year-round allergy symptoms. Taken daily as maintenance, not as a rescue treatment.

What are the mental health side effects of montelukast?

Montelukast has an FDA black box warning for serious neuropsychiatric events including agitation, aggression, depression, sleep disturbances, and suicidal thoughts. Report any mood or behavior changes to your doctor immediately.

Should I take montelukast in the morning or evening?

For asthma prevention, take in the evening. For allergies alone, any time is fine. Evening timing helps during nighttime when asthma symptoms are often worse.

Is montelukast safe for children?

Approved for children as young as 12 months. The neuropsychiatric side effects apply to children too — monitor for behavioral changes, mood swings, sleep problems, or aggression.

Can I stop montelukast suddenly?

Montelukast does not require tapering. However stopping means losing asthma or allergy protection. Always discuss stopping with your doctor first.

Related medications

💊AlbuterolShort-Acting Beta-2 Agonist (SABA) Bronchodilator 💊CetirizineSecond-Generation Antihistamine 💊LoratadineSecond-Generation Antihistamine 💊PrednisoneCorticosteroid

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This is an information resource — not medical advice.

🚨 If you are experiencing a medical emergency or think you may have taken too much of a medication, call emergency services (911 in the US) or go to your nearest emergency room immediately.

Information on this page is sourced from general pharmaceutical references and is provided for educational purposes only. Drug information may change — always verify with your pharmacist or prescriber. PillCodex.com is not affiliated with any pharmaceutical company.