Leukotriene Receptor AntagonistNot Controlled

Singulair®

Montelukast Sodium

Merck/Generic·FDA February 1998·
4mg granules (6mo–5yr)4mg chewable (2–5yr)5mg chewable (6–14yr)10mg tablet (15yr+)

Version 2025-04 · Last reviewed April 1, 2025 · Methodology

List Price

$250+ (brand historical)

With Insurance

$15–30

The Short Version

Plain-language summary

Singulair (Montelukast Sodium) blocks leukotrienes, inflammatory chemicals that tighten airways and trigger allergy symptoms. It's taken daily to prevent asthma attacks and reduce seasonal allergy symptoms, not to treat attacks already happening.

How it works: Montelukast blocks leukotriene receptors, the receptors that trigger bronchoconstriction, mucus production, and sneezing in response to allergens. Leukotrienes are released by mast cells during allergic reactions; blocking their receptor prevents these downstream effects.

What people most commonly report

Headache
18%
Neuropsychiatric effects (anxiety, nightmares, agitation)
10–15%
Aggression / behavioral changes (children)
10%
Abdominal pain
4%
Fatigue
3%

Common and usually mild; typically resolves. Ensure adequate hydration.

Check the evidence section for details on who funded the research.

What Else the Evidence Supports

Non-drug options with clinical backing

Allergen immunotherapy treats root cause; HEPA filtration and anti-inflammatory diet reduce inflammatory burden without any psychiatric side effects

Allergen immunotherapy (sublingual or injections)Emerging

Modifies underlying immune response; reduces both allergy and asthma symptoms long-term; only treatment that changes disease course.

HEPA air purificationEmerging

Reduces indoor allergen exposure by 50–90%; directly reduces allergic triggers.

Saline nasal rinse (Neti pot)Emerging

Clears allergens from nasal mucosa; reduces rhinitis symptoms significantly; zero side effects.

Quercetin (500mg twice daily)Emerging

Inhibits mast cell degranulation; reduces histamine release; anti-leukotriene properties similar to montelukast mechanism.

What This Really Costs

Long-term cost projection based on current pricing

Monthly

$23

without insurance

Annual

$276

without insurance

10 Years

$2.8K

without insurance

30 Years

$8.3K

without insurance

Lifestyle alternative: $0/month in prescriptions. Allergen immunotherapy (sublingual or injections) - Modifies underlying immune response; reduces both allergy and asthma symptoms long-term; only treatment that changes disease course.

The average American retiree spends $165,000 on healthcare after retirement (Fidelity, 2024). Informed choices today compound over decades.

Related Evidence

Explore related medications reviewed on EvidentMeds

Metabolic & Lifestyle Alternatives

Addressing Allergies & Asthma at the Root, Without Neuropsychiatric Risk

Allergen immunotherapy treats root cause; HEPA filtration and anti-inflammatory diet reduce inflammatory burden without any psychiatric side effects

Important context: Evidence quality varies across these approaches. Some are well-studied with randomized controlled trial data; others are based on observational or smaller studies. These interventions are not guaranteed to replace medication for all patients. Discuss with your doctor whether any of these are appropriate for your clinical situation.

Global Prescribing & Pricing

Many European countries moved Singulair to second-line or restricted use after the 2020 FDA black box warning, US prescribing continued largely unchanged

🇺🇸

United States

$15–30 (generic)/mo

Rate

Still widely prescribed despite 2020 black box; prescribing barely changed post-warning

Policy

FDA black box added March 2020; prescribers expected to counsel on neuropsychiatric risks but no mandatory restriction

Cover

Usually covered

🇬🇧

United Kingdom

~$5–12/mo

Rate

NICE downgraded to second-line; significant prescribing decline after 2020

Policy

MHRA issued same neuropsychiatric warning; NICE guidelines pushed toward ICS (inhaled corticosteroids) as first-line

Cover

Covered by NHS with review

🇩🇪

Germany

~$8–18/mo

Rate

Prescribing declined significantly post-2020 warning

Policy

BfArM issued strong warning; national prescribing guidelines shifted away from montelukast for mild disease

Cover

Covered by GKV

🇫🇷

France

~$6–14/mo

Rate

ANSM warned early; prescribing rate lower than US throughout

Policy

ANSM issued neuropsychiatric alert in 2019 before FDA; clinical reviewers re-evaluated indications

Cover

Covered by Sécurité Sociale

🇯🇵

Japan

~$10–22/mo

Rate

Lower use; behavioral first-line for pediatric asthma management

Policy

PMDA added neuropsychiatric warning; inhaled corticosteroids and trigger avoidance emphasized first

Cover

Covered by JHIS

The FDA knew about Singulair's neuropsychiatric signal as early as 2008. The black box warning wasn't added until 2020, 12 years later. During that gap, the drug was prescribed to tens of millions of children. France's ANSM warned its physicians a full year before the FDA acted. US prescribing rates barely changed after the 2020 black box was added.

Clinical Trials & Funding

Understanding who funds research helps contextualize results. Industry-funded trials are not automatically invalid - they undergo the same FDA review - but declared conflicts and sponsor effects are worth knowing. All linked trials can be verified on ClinicalTrials.gov.

Key Efficacy Results

Modest improvement in FEV1 (lung function) and allergy symptoms; neuropsychiatric events in 10–20% of pediatric patients based on post-marketing data

Referenced Studies

Each study shows its evidence level and Cochrane RoB-2 risk-of-bias rating - tap the bias badge for details.

Evidence & Transparency

Cochrane RoB-2 (Risk of Bias)

Badges reflect an editorial assessment using Cochrane's RoB-2 tool domains: randomization, intervention deviation, missing data, outcome measurement, and selective reporting. These are not certified Cochrane reviews. Learn more ↗

CMS Open Payments

Manufacturer payment disclosures are reported via the CMS Sunshine Act. Disclosure is legally required and does not imply bias or misconduct. Language uses "may," "suggests," or "appears", never definitive clinical claims. CMS Open Payments ↗

Live Clinical Trials

Live from ClinicalTrials.gov · refreshed every 4 hours

Currently enrolling, active, and recently completed studies involving Montelukast Sodium. Data is pulled directly from the U.S. National Library of Medicine.

Recent Research

Live from PubMed · peer-reviewed literature · refreshed every 4 hours

Most recently indexed clinical trials and systematic reviews mentioning Montelukast Sodium in PubMed.

Source Documentation

Structured citations for referenced clinical trials

Each referenced trial is listed with its registry ID, funding source, and bias assessment. Use the copy button to generate a formatted citation.

TrialRegistry IDCite
CAMP Trial (NIH/Merck)NCT00393835
Montelukast in Chronic AsthmaPMID:9665136
Montelukast Neuropsychiatric Review (2021)PMID:34019771

Bias ratings use Cochrane RoB-2 methodology. Editorial assessment - not a certified Cochrane review.

Our Methodology

Common Side Effects

While taking this medication, you may experience the following common side effects. We've included tips on how to manage them.

Headache

18%

Common and usually mild; typically resolves. Ensure adequate hydration.

Neuropsychiatric effects (anxiety, nightmares, agitation)

10–15%

FDA BLACK BOX 2020: Stop immediately if any behavioral changes, mood changes, or suicidal thoughts occur.

Aggression / behavioral changes (children)

10%

Document baseline behavior before starting. Inform school staff. Stop if aggression worsens.

Abdominal pain

4%

Take with food; usually self-limited.

Fatigue

3%

Usually mild; evening dosing may reduce daytime impact.

Serious Adverse Effects

  • BLACK BOX WARNING (2020): Serious neuropsychiatric events including suicidal thoughts and actions, FDA added this warning after 12 years of known signal
  • Depression, stop drug immediately and seek care if depressive symptoms emerge
  • Eosinophilic granulomatosis with polyangiitis (EGPA/Churg-Strauss), rare vasculitis; watch for rash, nerve pain, or worsening respiratory symptoms
  • Anaphylaxis, rare hypersensitivity reaction; get emergency care if severe allergic reaction occurs

Drug Interactions

Moderate Interactions (Caution)

Rifampin (rifampicin)Strong CYP3A4/2C8 inducer reduces montelukast levels by ~40%; reduces efficacy.
PhenobarbitalCYP induction reduces montelukast efficacy; may need dose adjustment.
GemfibrozilInhibits CYP2C8, increasing montelukast levels; monitor for CNS side effects.
Aspirin / NSAIDs (aspirin-sensitive asthma)Patients with aspirin-exacerbated respiratory disease may have breakthrough reactions; Singulair provides partial but incomplete protection.

Food Interactions

No significant food interactionsCan be taken with or without food; evening dosing recommended for asthma.

When to Contact Your Doctor

This medication requires ongoing medical supervision. The following situations warrant a prompt conversation with your prescribing physician - do not wait for your next scheduled appointment.

Contact soon if you notice

  • BLACK BOX WARNING (2020): Serious neuropsychiatric events including suicidal thoughts and actions, FDA added this warning after 12 years of known signal
  • Depression, stop drug immediately and seek care if depressive symptoms emerge
  • Eosinophilic granulomatosis with polyangiitis (EGPA/Churg-Strauss), rare vasculitis; watch for rash, nerve pain, or worsening respiratory symptoms
  • Anaphylaxis, rare hypersensitivity reaction; get emergency care if severe allergic reaction occurs
  • Suicidal thoughts or self-harm in children, discontinue immediately and seek emergency care

Also discuss if you want to

  • Review whether this medication is still appropriate for you
  • Consider dosage adjustments based on response
  • Explore lifestyle or non-drug alternatives
  • Understand stopping or tapering options
  • Plan monitoring labs and follow-up

In the US, call 911 or go to the nearest emergency room for severe symptoms. Poison Control: 1-800-222-1222.

Special Populations

Safety classifications for specific groups - discuss with your provider before use.

Category BPregnancy

Animal data reassuring; limited human data. Use only if clearly needed.

Use CautionBreastfeeding

Likely excreted in breast milk; monitor infant for sedation or behavioral changes.

Asthma Can Worsen During PerimenopauseMenopause / Hormonal

Asthma and allergic symptoms can worsen during the menopause transition due to hormonal effects on airway inflammation. Progesterone has bronchodilatory properties, and its decline during perimenopause can increase airway reactivity. If asthma or allergy symptoms are worsening in the late 30s or 40s, hormonal changes may be contributing.

BLACK BOX WARNING (2020)Children & Teens

FDA 2020: black box warning for serious neuropsychiatric events including suicidal thoughts and actions. FDA states drug should not be used for mild allergic rhinitis when other options exist. Discuss risks explicitly with parents.

No Dose AdjustmentOlder Adults

No specific concerns; standard dosing. Monitor for neuropsychiatric effects.

FDA Adverse Event Reports

Patient-filed reports from the FDA FAERS database · refreshed daily

Anecdotal data. Reports are not confirmed causation. Always consult your provider.

Community Reports

User-reported experiences - anonymous & anecdotal

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Premium subscribers can share their experience and confirm others' reports.

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Stopping This Medication Safely

Low Discontinuation RiskDocumented timeframe: Research indicates no pharmacological withdrawal risk

Montelukast does not cause physical dependence. Symptoms may return when stopped. Most importantly: neuropsychiatric symptoms (anxiety, mood changes, aggression, nightmares) often improve dramatically within days of stopping.

What Published Research Shows About Stopping This Medication

This summarizes what published research documents, it is not personal medical advice. Any changes to your medication require discussion with your prescribing physician.

  • ·Research shows no pharmacological taper is needed for montelukast
  • ·For patients stopping due to neuropsychiatric side effects, research supports immediate discontinuation
  • ·Switching to an alternative controller medication (inhaled corticosteroid) before or after stopping is documented in clinical guidelines
  • ·Research recommends monitoring respiratory symptoms for the first 2–4 weeks after stopping

Warning Symptoms, Contact Your Doctor If You Experience:

  • Suicidal thoughts or self-harm in children, discontinue immediately and seek emergency care
  • Severe worsening of asthma or allergic reaction requiring urgent treatment
  • Signs of Churg-Strauss (EGPA): rash, nerve pain, worsening symptoms with steroid taper

Never change or stop a medication without consulting your prescribing physician.

Questions for Your Doctor

$2.99, printable guide for your next appointment

Questions to Ask

  • 1.Has the 2020 FDA black box warning about suicidal thoughts been explained to me/my child?
  • 2.Is there a reason to use Singulair specifically over an inhaled corticosteroid, which does not carry neuropsychiatric risks?
  • 3.For my child: what behavioral changes should I watch for, and what should I do if I see them?
  • 4.Has allergen immunotherapy been discussed as a long-term solution?
  • 5.What are the HEPA filtration and trigger-avoidance recommendations for my home environment?

Lab Tests to Request

  • Spirometry / peak flow (asthma)
  • Allergy skin testing or IgE RAST panel
  • Vitamin D level
  • Complete allergy trigger assessment
  • Behavior/mood baseline documentation before starting (for children)

Medical Disclaimer

The information on this page is compiled from publicly available clinical trial data, FDA prescribing information, and peer-reviewed literature. It is provided for educational purposes only and does not constitute medical advice, diagnosis, or treatment recommendations. Individual responses to medications vary. Always consult a qualified healthcare provider before starting, stopping, or changing any medication.

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