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Singulair
Montelukast
$135.00
4mg · 3 × 28 tablets · 3 months supply
BrandBranded medicine· By MSD
$45.00 per month
Strength
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Annual cost
$585a year at this pack size
Prescription required
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FDA boxed warningSerious neuropsychiatric events
Serious neuropsychiatric (NP) events have been reported with the use of montelukast sodium tablets. The types of events reported were highly variable, and included, but were not limited to, agitation, aggression, depression, sleep disturbances, suicidal thoughts and behavior (including suicide). The mechanisms underlying NP events associated with montelukast sodium use are currently not well understood
Because of the risk of NP events, the benefits of montelukast sodium may not outweigh the risks in some patients, particularly when the symptoms of disease may be mild and adequately treated with alternative therapies. Reserve use of montelukast sodium for patients with allergic rhinitis who have an inadequate response or intolerance to alternative therapies
. In patients with asthma or exercise-induced bronchoconstriction, consider the benefits and risks before prescribing montelukast sodium.
Discuss the benefits and risks of montelukast sodium with patients and caregivers when prescribing montelukast sodium. Advise patients and/or caregivers to be alert for changes in behavior or new NP symptoms when taking montelukast sodium. If changes in behavior are observed, or if new NP symptoms or suicidal thoughts and/or behavior occur, advise patients to discontinue montelukast sodium and contact a healthcare provider immediately
Serious neuropsychiatric events have been reported in patients taking montelukast sodium tablets.
Discuss benefits and risks of montelukast sodium tablets with patients and caregivers.
Monitor for neuropsychiatric symptoms in patients taking montelukast sodium tablets.
Discontinue montelukast sodium tablets immediately if neuropsychiatric symptoms occur.
Because the benefits of montelukast sodium tablets may not outweigh the potential risk of neuropsychiatric symptoms in patients with allergic rhinitis, reserve use for patients who have an inadequate response or intolerance to alternative therapies.
About Singulair
Overview
Singulair contains montelukast, a prescription medicine known as a leukotriene receptor antagonist. In people aged 15 years and older, montelukast tablets are used to prevent and manage asthma over time, prevent exercise-induced airway narrowing, and relieve seasonal or year-round allergic rhinitis symptoms when other treatments have not worked adequately or cannot be tolerated. It works by blocking a specific receptor for substances called leukotrienes. It is not used to treat an acute asthma attack.
What it treats
- Prevention and long-term treatment of asthma in patients aged 15 years and older; not for treating an acute asthma attack. - Prevention of exercise-induced narrowing of the airways in patients aged 15 years and older. - Relief of seasonal or year-round allergic rhinitis symptoms in patients aged 15 years and older, only when alternative treatments have not worked adequately or are not tolerated.
Safety information
Side effects
Commonly reported side effects include upper respiratory infections, fever, headache, sore throat, cough, stomach pain, diarrhoea, ear infections, flu, runny nose and sinus infections. Serious changes in mood, behaviour, thinking or sleep have been reported, including agitation, aggression, anxiety, depression, unusual dreams, insomnia, sleepwalking, hallucinations, confusion, memory or attention problems, and suicidal thoughts or actions, including suicide. These can occur in people with or without a history of mental health problems, during treatment or after stopping. Stop montelukast and contact a healthcare professional immediately if these symptoms or any new changes in behaviour occur. Symptoms may continue after treatment is stopped. Other serious reactions reported include severe allergic reactions, swelling beneath the skin, severe skin reactions, liver injury, inflammation of the pancreas, seizures, increased bleeding and low blood platelet counts. These warrant immediate medical attention. Their frequency and whether montelukast caused them cannot always be determined from the reports. In people with asthma, an increase in certain white blood cells, sometimes with inflammation of blood vessels, has also been reported. Contact a doctor promptly for a new rash, worsening breathing, heart problems, or numbness or tingling. Some cases occurred when oral corticosteroid treatment was reduced; a causal link with montelukast has not been established.
FDA boxed warning
Serious neuropsychiatric events
Serious neuropsychiatric (NP) events have been reported with the use of montelukast sodium tablets. The types of events reported were highly variable, and included, but were not limited to, agitation, aggression, depression, sleep disturbances, suicidal thoughts and behavior (including suicide). The mechanisms underlying NP events associated with montelukast sodium use are currently not well understood
Because of the risk of NP events, the benefits of montelukast sodium may not outweigh the risks in some patients, particularly when the symptoms of disease may be mild and adequately treated with alternative therapies. Reserve use of montelukast sodium for patients with allergic rhinitis who have an inadequate response or intolerance to alternative therapies
. In patients with asthma or exercise-induced bronchoconstriction, consider the benefits and risks before prescribing montelukast sodium.
Discuss the benefits and risks of montelukast sodium with patients and caregivers when prescribing montelukast sodium. Advise patients and/or caregivers to be alert for changes in behavior or new NP symptoms when taking montelukast sodium. If changes in behavior are observed, or if new NP symptoms or suicidal thoughts and/or behavior occur, advise patients to discontinue montelukast sodium and contact a healthcare provider immediately
Serious neuropsychiatric events have been reported in patients taking montelukast sodium tablets.
Discuss benefits and risks of montelukast sodium tablets with patients and caregivers.
Monitor for neuropsychiatric symptoms in patients taking montelukast sodium tablets.
Discontinue montelukast sodium tablets immediately if neuropsychiatric symptoms occur.
Because the benefits of montelukast sodium tablets may not outweigh the potential risk of neuropsychiatric symptoms in patients with allergic rhinitis, reserve use for patients who have an inadequate response or intolerance to alternative therapies.
A boxed warning is the strongest warning the US Food and Drug Administration requires on a medicine label. Text is taken from the official label, with internal section references removed.
When to call your doctor
If symptoms are severe or getting worse quickly, seek emergency care rather than waiting.
Before taking this medicine
Do not take montelukast if you are allergic to it or any component of the tablets. Serious changes in mood, behaviour or sleep have been reported, including depression, hallucinations and suicidal thoughts or actions. These can occur with or without a history of mental health problems, during treatment or after stopping. If these symptoms develop, stop taking montelukast and contact a healthcare professional immediately. Symptoms may persist after stopping. For allergic rhinitis, montelukast should be reserved for people whose symptoms are not adequately controlled by other treatments or who cannot tolerate them. Montelukast must not be used to treat an acute asthma attack. Keep appropriate rescue medication available. Do not abruptly replace inhaled or oral corticosteroids with montelukast. If you are sensitive to aspirin, continue to avoid aspirin and non-steroidal anti-inflammatory drugs (NSAIDs). Increased levels of eosinophils, a type of white blood cell, and inflammation of blood vessels have been reported, sometimes when oral corticosteroid treatment was reduced. A causal link to montelukast has not been established. Symptoms requiring medical assessment include a rash, worsening breathing, heart problems or nerve symptoms. Pregnancy studies have not established a link to major birth defects, but the evidence has limitations. Montelukast passes into breast milk; available data do not suggest a significant risk to infants, but its effects on milk production are unknown. Treatment during breastfeeding requires consideration of the benefits and potential risks. Safety and effectiveness have not been established in children under 12 months for asthma, under 6 months for year-round allergic rhinitis, or under 6 years for exercise-induced airway narrowing. Some older adults may be more sensitive to the medicine.
Interactions
The label states that no dose adjustment is needed when montelukast is taken with theophylline, prednisone, prednisolone, oral contraceptives, fexofenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, medicines for sleep or sedation, non-steroidal anti-inflammatory drugs (NSAIDs), benzodiazepines, decongestants or medicines that increase the activity of CYP enzymes. The supplied label text does not describe food or supplement interactions.
Using Singulair
Dosing
Dosing is set by your prescriber. Each health care professional may prescribe medication differently according to a patient's medical history and condition, so follow the directions on your prescription label and speak to your doctor or pharmacist before changing anything.
Storage
Store below 25°C in a dry place, in the original pack, away from direct light and moisture. Do not keep it in a bathroom. Keep all medicines out of the sight and reach of children.
Clinical information on this page is summarised from the US FDA label MONTELUKAST SODIUM TABLET [REMEDYREPACK INC.] (DailyMed, retrieved 19 September 2026).
Patient information and references
Official and supporting information to read alongside advice from your prescriber or pharmacist.
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