Prescription medication · Leukotriene Receptor Antagonist
montelukast
Also sold as Singulair. Montelukast is used to prevent asthma symptoms and treat long-term asthma.
Data updated 2026-05-15
- 78,359
- FDA reportsOften reported
- 8
- InteractionsFew interactions
- 99% less
- Generic vs brandHuge savings
- In shortage
- FDA status
What the data shows
montelukast (Singulair) is a prescription Leukotriene Receptor Antagonist, more reported than most tracked drugs (78,359 FDA reports), whose generic costs a fraction of the brand (about 99% less).
Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.
montelukast (Singulair) is a prescription Leukotriene Receptor Antagonist. Montelukast is used to prevent asthma symptoms and treat long-term asthma.
Montelukast is a medicine that helps control asthma and allergies. It works by blocking certain natural substances in your body that cause asthma and allergy symptoms.
Verify with FDA → · CMS NADAC pricing →
Drug Shortage Alert
montelukast is currently listed as to be discontinued by the FDA. Affected manufacturer: Organon.
View all drug shortages →Drug Pricing (NADAC)
Brand Price
$8.40/unit
Generic Price
$0.05/unit
Generic Savings
99%
Generic Available
Yes (24 manufacturers)
Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →
What it does
Montelukast is used to prevent asthma symptoms and treat long-term asthma.
Common side effects
Upper respiratory infection, Fever, Headache
Key warnings
Do not use montelukast to treat a sudden asthma attack.
The sections below are summarized in plain English from montelukast's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.
How It Works
This medicine blocks leukotrienes, which are substances your body releases that cause swelling in the lungs and tightening of the muscles around your airways. By blocking these substances, montelukast helps you breathe easier. It also reduces allergy symptoms.
How to Take It
Take montelukast once a day, in the evening for asthma or once daily for allergies. For exercise, take one dose at least 2 hours before you exercise. Do not take an extra dose within 24 hours. You can take it with or without food.
This is a plain-language summary of montelukast's FDA labeling, not individualized dosing advice. Ask a pharmacist or prescriber before changing how you take this medication.
Pregnancy & Breastfeeding
If you are pregnant, talk to your doctor before taking montelukast. It is not known if montelukast passes into breast milk, so talk to your doctor if you are breastfeeding.
This is a plain-language summary of montelukast's FDA labeling, not individualized advice. Ask a pharmacist or prescriber about pregnancy or breastfeeding on this medication.
Missed Dose
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule.
This is a plain-language summary of montelukast's FDA labeling, not individualized advice. Ask a pharmacist or prescriber what to do about your specific missed dose.
Storage
Store montelukast tablets at room temperature, away from moisture and light, and in the original container.
Side Effects (from patient reports)
Based on 78,359 FDA adverse event reports.
Most-reported reactions
Adverse reactions in FAERS for montelukast, by number of reports
- Difficulty breathing
Difficulty breathing
7,724 reports
- Asthma
Asthma
7,439 reports
- Tiredness
Tiredness
5,505 reports
- Headache
Headache
4,785 reports
- Cough
Cough
4,617 reports
- Feeling sick to your stomach
Feeling sick to your stomach
4,213 reports
- Pneumonia
Pneumonia
3,835 reports
- Pain
Pain
3,602 reports
- Anxiety
Anxiety
3,466 reports
- Diarrhea
Diarrhea
3,414 reports
What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.
Reports over time
Adverse-event reports filed for montelukast each year to the FDA Adverse Event Reporting System (FAERS).
Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.
Where montelukast sits
montelukast has more FDA adverse-event reports than 82% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.
Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is montelukast; the line is the median (50th percentile).
FDA Adverse Event Report Analysis
Detailed analysis of 78,359 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2002–2025.
Total Reports
78,359
Reports Mentioning Death
3,777
4.8% of reports — not proof of cause
Hospitalization Reports
21,518
Top Indication
Product Used For Unknown Indication
Gender Distribution
Age Distribution
Most Reported Adverse Reactions (FAERS)
| # | Reaction | Reports |
|---|---|---|
| 1 | DYSPNOEA | 7,723 |
| 2 | ASTHMA | 7,439 |
| 4 | FATIGUE | 5,505 |
| 5 | HEADACHE | 4,786 |
| 6 | COUGH | 4,617 |
| 7 | NAUSEA | 4,214 |
| 9 | PNEUMONIA | 3,835 |
| 10 | PAIN | 3,602 |
| 11 | ANXIETY | 3,466 |
| 12 | DIARRHOEA | 3,414 |
| 13 | WHEEZING | 3,264 |
| 14 | MALAISE | 2,946 |
| 15 | DIZZINESS | 2,922 |
| 16 | PRURITUS | 2,900 |
| 17 | RASH | 2,866 |
Reactions in Death Reports
Reactions in Hospitalization Reports
Source: FDA FAERS (Adverse Event Reporting System) FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation
Serious Warnings
Do not use montelukast to treat a sudden asthma attack. Always have your rescue medicine with you. Do not suddenly stop taking steroid medicines if you are also taking montelukast. Some patients have experienced changes in behavior or mood, including suicidal thoughts. Tell your doctor right away if you notice these changes.
Known Drug Interactions
DRUG INTERACTIONS No dose adjustment is needed when montelukast sodium is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, terfenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants, and Cytochrome P450 (CYP) enzyme inducers [see Clinical Pharmacology (12.3)] .
Mechanism: These two medicines do not have a known interaction that changes how they work in your body.
What to do: You can take these medications together at your normal doses without needing any adjustments.
DRUG INTERACTIONS No dose adjustment is needed when montelukast sodium is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, terfenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants, and Cytochrome P450 (CYP) enzyme inducers [see Clinical Pharmacology (12.3)] .
Mechanism: These two medicines do not interfere with each other, so they do not change how the other drug is processed.
What to do: No dose changes are needed when you take these two medicines at the same time.
DRUG INTERACTIONS No dose adjustment is needed when montelukast sodium is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, terfenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants, and Cytochrome P450 (CYP) enzyme inducers [see Clinical Pharmacology (12.3)] .
Mechanism: There is no evidence that these medicines affect each other's levels or performance in the body.
What to do: You can safely take these medicines together without adjusting your current dosages.
DRUG INTERACTIONS No dose adjustment is needed when montelukast sodium is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, terfenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants, and Cytochrome P450 (CYP) enzyme inducers [see Clinical Pharmacology (12.3)] .
Mechanism: These drugs do not significantly change how the body processes each other.
What to do: You can take these medicines together without needing to change your dose.
DRUG INTERACTIONS No dose adjustment is needed when montelukast sodium is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, terfenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, non-steroidal anti-inflammatory agents, benzodiazepines, decongestants, and Cytochrome P450 (CYP) enzyme inducers [see Clinical Pharmacology (12.3)] .
Mechanism: These medications do not interfere with each other's levels in the blood.
What to do: No dose changes are necessary when taking these two drugs together.
This is a plain-language summary of interactions documented in FDA labeling, not individualized advice. Ask a pharmacist or prescriber before combining medications.
Common Questions
Can I use montelukast for a sudden asthma attack?
Can I stop taking my steroid medicine if I take montelukast?
What should I do if I experience mood changes while taking montelukast?
Can I take montelukast if I am allergic to aspirin?
How old do you have to be to take montelukast?
Can I take montelukast if I have phenylketonuria (PKU)?
Does montelukast interact with other medicines?
How long does it take for montelukast to start working?
Can I take an extra dose of montelukast if I forget to take it before exercise?
What does 'leukotriene receptor antagonist' mean?
What are the common side effects of montelukast?
Does montelukast interact with other medications?
What drug class is montelukast?
Is there a generic version of montelukast?
Is montelukast safe during pregnancy?
Has montelukast been recalled?
Is montelukast currently in shortage?
Active Recalls
cGMP Deviations for the manufacturing Firm (Accord Healthcare) after their inspection.
Preferred Pharmaceuticals, Inc.
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Medication Guides
Understanding Drug Interactions
How CYP450 enzymes, inhibitors, and inducers affect your medications
Generic vs Brand Name Drugs
FDA requirements, cost savings, and when the difference matters
Narrow Therapeutic Index Drugs
Why some drugs demand precise dosing and monitoring
Common Drug Interactions
Dangerous medication combinations and how to protect yourself
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What the FDA Data Shows for montelukast
The FDA label for montelukast (sold under brand names such as Singulair) classifies it as a prescription-only medication in the Leukotriene Receptor Antagonist class. Montelukast is used to prevent asthma symptoms and treat long-term asthma. Official labeling lists 12 commonly reported side effects, including Upper respiratory infection, Fever, Headache.
Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 78,359 voluntary reports. The database also lists 8 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated minor severity. NADAC pricing from CMS shows a generic unit cost of $0.05 versus $8.40 for the brand - a 99% generic savings.
Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history (currently 1 recall record on file), and patent information further shape supply and switching decisions. This page summarizes public FDA data for educational purposes only and is not a substitute for professional medical advice, always consult a licensed healthcare provider before starting, stopping, or changing any medication.
Data Sources
Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC). Shortage status: FDA Drug Shortages Database.
FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. Always consult a healthcare professional before making medication decisions.
Last updated: October 1, 2023
Read our methodology - how this data is sourced, computed, and verified.
Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled and last refreshed May 2026. See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a correction.
All federal data sources used on this page
- FDA Orange Book - approved drug products with therapeutic equivalence. accessdata.fda.gov/cder/ob
- FDA DailyMed - NIH-hosted drug labeling for FDA-approved meds. dailymed.nlm.nih.gov
- FDA Adverse Event Reporting System (FAERS) - post-marketing safety surveillance. fda.gov/drugs/faers
- NLM RxNorm - standardized clinical drug nomenclature. nlm.nih.gov/research/umls/rxnorm
- CMS Medicare Part B Drug Average Sales Price Files - federal drug pricing data. cms.gov/medicare/part-b-drugs/asp
- FDA Drug Shortages Database - current and resolved drug shortage tracking. accessdata.fda.gov/drugshortages