Singulair (Montelukast): Prescription 10 mg Leukotriene Receptor Antagonist Tablets for Asthma, Allergic Rhinitis & Exercise-Induced Bronchoconstriction

Information last reviewed: May 2026 — for educational purposes only.

Singulair is a brand name for montelukast sodium, a selective leukotriene receptor antagonist (LTRA) used as a controller medication for chronic asthma, seasonal and perennial allergic rhinitis, and the prevention of exercise-induced bronchoconstriction. Montelukast is taken as an oral tablet once daily, typically in the evening, and is intended for ongoing disease control rather than acute symptom relief. It requires a prescription in all major markets. In 2020, the US FDA added a Boxed Warning (the FDA’s most serious safety alert) regarding serious neuropsychiatric events associated with montelukast use.

What Is Montelukast?

Montelukast works by blocking cysteinyl leukotriene receptors (CysLT1) in the airways and nasal passages. Leukotrienes are inflammatory lipid mediators released by mast cells and eosinophils in response to allergens and irritants. They cause bronchoconstriction, increased mucus secretion, and attraction of further inflammatory cells. By blocking leukotriene binding at its receptor, montelukast reduces airway inflammation and hyperresponsiveness over time.

Unlike inhaled corticosteroids, montelukast acts via an entirely different anti-inflammatory pathway, making it useful as an add-on therapy when inhaled steroids alone do not provide adequate control, or as an alternative for patients who cannot use inhalers effectively (e.g., some young children). It also reliably reduces the nasal symptoms of allergic rhinitis and is sometimes used primarily for rhinitis in patients without asthma.

Prescription-Only Status

Montelukast is a prescription-only medicine in the United States, United Kingdom, European Union, Canada, and Australia. It is not available over the counter. Due to the FDA Boxed Warning on neuropsychiatric events (see FAQ below), current prescribing guidelines recommend that montelukast be reserved for patients for whom the benefits clearly outweigh the risks, particularly for those with mild allergic rhinitis for whom antihistamines or nasal corticosteroids have been sufficient.

Tablet Strengths and Forms

Montelukast is available in three strength presentations designed for different age groups:

• 4 mg chewable tablet — for children aged 2–5 years; cherry flavoured; used for asthma control or allergic rhinitis in young children who cannot swallow solid tablets
• 5 mg chewable tablet — for children aged 6–14 years; same cherry flavouring
• 10 mg film-coated tablet — standard adult and adolescent dose (15 years and older); taken once daily, preferably in the evening
• 4 mg oral granules — sachet form for children aged 6 months to 5 years; granules can be mixed into soft food (soft food must be at room temperature or below; not hot liquids)

All forms are taken once daily. For asthma, evening dosing is preferred as airway inflammation typically peaks in the early morning hours. For allergic rhinitis alone, dosing time is flexible.

Price and Generic Montelukast

Generic montelukast became widely available in the United States after the Singulair patent expired in 2012. Generic montelukast 10 mg tablets are significantly less expensive than branded Singulair and are considered therapeutically equivalent by the FDA. Patients with prescription drug coverage may pay a low or zero co-pay for generic montelukast. Without coverage, pharmacy discount cards (GoodRx and similar) can reduce the cost to a few dollars per month for generic 10 mg tablets.

Frequently Asked Questions

What is the FDA Boxed Warning for Singulair?

In March 2020, the FDA added a Boxed Warning to montelukast noting serious neuropsychiatric events reported in some patients, including agitation, aggression, anxiousness, depression, disorientation, sleep disturbances, suicidal thinking and behaviour, and tremor. The warning advises prescribers to consider the risks and benefits carefully, particularly for patients being treated only for allergic rhinitis (where alternatives such as antihistamines and nasal steroids are effective). Patients or caregivers noticing behavioural changes should contact their prescriber promptly.

Is Singulair / montelukast available over the counter?

No. Montelukast requires a prescription in all major markets. Following the addition of the Boxed Warning, regulatory guidance specifically steers prescribers toward OTC alternatives for patients with mild rhinitis not complicated by asthma.

Can montelukast be used for exercise-induced asthma?

Yes. Montelukast is licensed for prevention of exercise-induced bronchoconstriction. A single 10 mg tablet taken at least 2 hours before exercise is the standard prophylactic approach. However, it is less effective than a pre-exercise albuterol (Ventolin) dose for most patients and is generally used when SABAs are not tolerated or as an adjunct.

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