This grade answers one narrow question: how strong is the public evidence and safety record behind this drug, and how clean is its money trail and court record? It is not a verdict on whether the drug is right for you.
WARNING: SERIOUS NEUROPSYCHIATRIC EVENTS Serious neuropsychiatric (NP) events have been reported with the use of SINGULAIR. 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 SINGULAIR use are currently not well understood [see Warnings and Precautions (5.1) ] . Because of the risk of NP events, the benefits of SINGULAIR 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 SINGULAIR for patients with allergic rhinitis who have an inadequate response or intolerance to alternative therapies [see Indications and Usage (1.3) ] . In patients with asthma or exercise-induced bronchoconstriction, consider the benefits and risks before prescribing SINGULAIR. Discuss the benefits and risks of SINGULAIR with patients and caregivers when prescribing SINGULAIR. Advise patients and/or caregivers to be alert for changes in behavior or new NP symptoms when taking SINGULAIR. If changes in behav...
Warnings the FDA chose to announce publicly after approval, as opposed to quiet label edits. Class-wide items name the drug's class, not this drug specifically.
is a leukotriene receptor antagonist indicated for: Prophylaxis and chronic treatment of asthma in patients 12 months of age and older ( 1.1 ). Acute prevention of exercise-induced bronchoconstriction (EIB) in patients 6 years of age and older ( 1.2 ). Relief of symptoms of allergic rhinitis (AR): seasonal allergic rhinitis (SAR) in patients 2 years of age and older, and perennial allergic rhinitis (PAR) in patients 6 months of age and older. Reserve use for patients who have an inadequate response or intolerance to alternative therapies ( 1.3 ). Limitations of Use: Not indicated to treat an acute asthma attack ( 5.2 ). 1.1 Asthma SINGULAIR ® is indicated for the prophylaxis and chronic treatment of asthma in adults and pediatric patients 12 months of age and older. 1.2 Exercise-Induced Bronchoconstriction (EIB) SINGULAIR is indicated for prevention of exercise-induced bronchoconstriction (EIB) in patients 6 years of age and older. 1.3 Allergic Rhinitis SINGULAIR is indicated for the relief of symptoms of seasonal allergic rhinitis in patients 2 years of age and older and perennial allergic rhinitis in patients 6 months of age and older. Because the benefits of SINGULAIR may not ou...
is contraindicated in patients with hypersensitivity to any of its components. Hypersensitivity to any component of SINGULAIR ( 4 ).
Do not prescribe SINGULAIR to treat an acute asthma attack ( 5.2 ). Advise patients to have appropriate rescue medication available ( 5.2 ). Inhaled corticosteroid may be reduced gradually. Do not abruptly substitute SINGULAIR for inhaled or oral corticosteroids ( 5.3 ). Patients with known aspirin sensitivity should continue to avoid aspirin or non-steroidal anti-inflammatory agents while taking SINGULAIR ( 5.4 ). Systemic eosinophilia, sometimes presenting with clinical features of vasculitis consistent with Churg-Strauss syndrome, has been reported. These events have been sometimes associated with the reduction of oral corticosteroid therapy ( 5.5 and 6.2 ). Inform patients with phenylketonuria that the 4-mg and 5-mg chewable tablets contain phenylalanine ( 5.6 ). 5.1 Neuropsychiatric Events Serious neuropsychiatric (NP) events have been reported with use of SINGULAIR. These postmarketing reports have been highly variable and included, but were not limited to, agitation, aggressive behavior or hostility, anxiousness, depression, disorientation, disturbance in attention, dream abnormalities, dysphemia (stuttering), hallucinations, insomnia, irritability, memory impairment, obsess...
The following clinically significant adverse reactions are described elsewhere in the labeling: Neuropsychiatric Events [see Warnings and Precautions (5.1) ] Most common adverse reactions (incidence ≥5% and greater than placebo listed in descending order of frequency): upper respiratory infection, fever, headache, pharyngitis, cough, abdominal pain, diarrhea, otitis media, influenza, rhinorrhea, sinusitis, otitis ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Organon LLC, a subsidiary of Organon & Co., Inc., at 1-844-674-3200 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. In the following description of clinical trials experience, adverse reactions are listed regardless of causality assessment. The most common adverse reactions (incidence ≥5% and greater than placebo; listed in descending order of frequency) in controlled clinical trials were: upper respiratory infection,...
Indications and Usage ( 1.3 , 1.4 ) 02/2021 Dosage and Administration ( 2.1 , 2.2 , 2.3 , 2.4 ) 02/2021 Warnings and Precautions ( 5.1 , 5.6 ) 02/2021
Source: FDA SPL label for SINGULAIR (Organon LLC), effective 20250430. Full label on DailyMed.
These are counts of reports people filed, not rates of harm. Anyone can file one, and nobody checks whether the drug was the cause. Millions of doses are taken for every report sent, so the useful part is how this drug compares with the average across all drugs.
| 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
|---|---|---|---|---|---|---|---|
| 14,187 | 14,759 | 13,286 | 12,196 | 11,601 | 12,753 | 12,510 | 6,508 |
2,540 reports blaming this drug for every million Medicare prescriptions filled, which is 0.9× the typical drug on this site. (31,684 reports in 2024–2026, against 12,473,122 Medicare fills in one year. This is the one number here that accounts for how many people take the drug.)
Source: the FDA's Adverse Event Reporting System (FAERS). Reports are voluntary and unverified. Drugs that are prescribed a lot, in the news, or in lawsuits attract more reports, so the percentages are compared with the whole database to correct for that partly, not fully.
| Date | Class | Firm | Reason |
|---|---|---|---|
| 10/2023 | Class II | Dr. Reddy's Laboratories, Inc. | Presence of Foreign Tablet(s)/Capsule(s): A foreign tablet was found in a bottle of Montelukast Sodium Tablets, USP 10mg, identified as metoprolol 25 mg. |
| 02/2023 | Class II | Accord Healthcare, Inc. | CGMP Deviations: recalling drug products following an FDA inspection. |
| 01/2020 | Class III | Macleods Pharma Usa Inc | Failed Dissolution Specifications: testing revealed low out of specification result in one lot of product |
| 08/2018 | Class II | Hetero Labs Limited Unit V | Discoloration: A complaint was received from a pharmacist for the presence of blue specks on tablets. |
| 08/2018 | Class I | Hetero Labs Limited Unit V | Labeling: Label Mix-Up - One lot labeled Montelukast Sodium Tablets 10 mg tablets may contain 90 tablets of Losartan Potassium 50 mg. |
| 01/2017 | Class III | Hetero USA Inc | Discoloration: the firm received a complaint of a sealed bottle in which tablets inside had blue spots and a blue powder inside the bottle. |
Class I = reasonable probability of serious harm. Class II = temporary or reversible harm. Class III = unlikely to harm. Most generic recalls are manufacturing or labeling defects for one lot, not a verdict on the molecule.
Counts measure how much evidence exists and how transparent it is, not how big the benefit is. For that, ask your prescriber: if 100 people like me took this, how many would get better because of it, and how many would be harmed? (Doctors call these the "number needed to treat" and "number needed to harm.") It differs by condition and is the number drug ads leave out. Sources: PubMed, ClinicalTrials.gov.
In 2024, drug companies reported $0 in payments to US physicians and hospitals tied to this drug across 0 transactions.
No pending federal MDL names this drug or its brands.
Not named in any federal pharmaceutical settlement of $100M or more on record.
Sources: CMS Open Payments (Sunshine Act); Judicial Panel on Multidistrict Litigation pending docket list; DOJ settlements as tabulated on Wikipedia with links to the primary record. State-court and individual suits are not included.
| Product | Fills | $/fill |
|---|---|---|
| Montelukast Sodium | 12,462,037 | $11 |
| Singulair | 11,085 | $516 |
Same ATC pharmacological class, graded ones first, best grade at the top. Being in the same class does not make them interchangeable for your condition; it makes them worth asking about.