What are the side effects of montelukast (Singulair) in pediatric patients?

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Last updated: March 19, 2025View editorial policy

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From the Guidelines

Montelukast can cause several side effects in children, including headache, abdominal pain, and upper respiratory infections, as well as more concerning neuropsychiatric side effects such as behavior changes, mood disturbances, sleep disturbances, and in rare cases, suicidal thoughts. According to the most recent evidence from 1, the medication works by blocking leukotriene receptors to reduce inflammation, but these receptors are also present in the brain, potentially affecting neurological function.

Key Side Effects

  • Headache
  • Abdominal pain
  • Upper respiratory infections
  • Neuropsychiatric side effects, including:
    • Behavior changes
    • Mood disturbances
    • Sleep disturbances
    • Rare cases of suicidal thoughts

Monitoring and Reporting

Parents should monitor their children closely for these symptoms, especially during the first weeks of treatment or after dose changes. The FDA has added a boxed warning about the serious mental health side effects, so it's essential to report any unusual changes in behavior or mood to a healthcare provider immediately.

Management of Side Effects

If concerning side effects develop, don't stop the medication abruptly but consult with the prescribing doctor who may recommend alternative treatments for the child's asthma or allergies. The evidence from 1 and 1 supports the use of montelukast in pediatric patients, but it's crucial to weigh the benefits against the potential risks and monitor patients closely for any adverse effects.

From the FDA Drug Label

Pediatric Patients 6 to 14 Years of Age with Asthma SINGULAIR has been evaluated for safety in 476 pediatric patients 6 to 14 years of age Cumulatively, 289 pediatric patients were treated with SINGULAIR for at least 6 months, and 241 for one year or longer in clinical trials. The safety profile of SINGULAIR in the 8-week, double-blind, pediatric efficacy trial was generally similar to the adult safety profile In pediatric patients 6 to 14 years of age receiving SINGULAIR, the following events occurred with a frequency ≥2% and more frequently than in pediatric patients who received placebo, regardless of causality assessment: pharyngitis, influenza, fever, sinusitis, nausea, diarrhea, dyspepsia, otitis, viral infection, and laryngitis The frequency of less common adverse events was comparable between SINGULAIR and placebo. With prolonged treatment, the adverse experience profile did not significantly change. In studies evaluating growth rate, the safety profile in these pediatric patients was consistent with the safety profile previously described for SINGULAIR In a 56-week, double-blind study evaluating growth rate in pediatric patients 6 to 8 years of age receiving SINGULAIR, the following events not previously observed with the use of SINGULAIR in this age group occurred with a frequency ≥2% and more frequently than in pediatric patients who received placebo, regardless of causality assessment: headache, rhinitis (infective), varicella, gastroenteritis, atopic dermatitis, acute bronchitis, tooth infection, skin infection, and myopia. Pediatric Patients 2 to 5 Years of Age with Asthma SINGULAIR has been evaluated for safety in 573 pediatric patients 2 to 5 years of age in single- and multiple-dose studies Cumulatively, 426 pediatric patients 2 to 5 years of age were treated with SINGULAIR for at least 3 months, 230 for 6 months or longer, and 63 patients for one year or longer in clinical trials. SINGULAIR 4 mg administered once daily at bedtime was generally well tolerated in clinical trials In pediatric patients 2 to 5 years of age receiving SINGULAIR, the following events occurred with a frequency ≥2% and more frequently than in pediatric patients who received placebo, regardless of causality assessment: fever, cough, abdominal pain, diarrhea, headache, rhinorrhea, sinusitis, otitis, influenza, rash, ear pain, gastroenteritis, eczema, urticaria, varicella, pneumonia, dermatitis, and conjunctivitis. Pediatric Patients 6 to 23 Months of Age with Asthma Safety and effectiveness in pediatric patients younger than 12 months of age with asthma have not been established. SINGULAIR has been evaluated for safety in 175 pediatric patients 6 to 23 months of age The safety profile of SINGULAIR in a 6-week, double-blind, placebo-controlled clinical study was generally similar to the safety profile in adults and pediatric patients 2 to 14 years of age. SINGULAIR administered once daily at bedtime was generally well tolerated In pediatric patients 6 to 23 months of age receiving SINGULAIR, the following events occurred with a frequency ≥2% and more frequently than in pediatric patients who received placebo, regardless of causality assessment: upper respiratory infection, wheezing; otitis media; pharyngitis, tonsillitis, cough; and rhinitis

The side effects of montelukast (Singulair) in pediatric patients are:

  • Pharyngitis
  • Influenza
  • Fever
  • Sinusitis
  • Nausea
  • Diarrhea
  • Dyspepsia
  • Otitis
  • Viral infection
  • Laryngitis
  • Headache
  • Rhinitis (infective)
  • Varicella
  • Gastroenteritis
  • Atopic dermatitis
  • Acute bronchitis
  • Tooth infection
  • Skin infection
  • Myopia
  • Cough
  • Abdominal pain
  • Rhinorrhea
  • Rash
  • Ear pain
  • Eczema
  • Urticaria
  • Pneumonia
  • Dermatitis
  • Conjunctivitis
  • Upper respiratory infection
  • Wheezing
  • Otitis media
  • Tonsillitis 2

From the Research

Side Effects of Montelukast in Pediatric Patients

The side effects of montelukast (Singulair) in pediatric patients include:

  • Sleep disturbance, affecting 15.1% of participants 3
  • Agitation, affecting 10.4% of participants 3
  • Pain, affecting 9.4% of participants 3
  • Hyperactivity, affecting 6.8% of participants 3
  • Neuropsychiatric events, such as anxiety, depression, sleep disturbance, and suicidality, although the data is insufficient 4
  • Churg-Strauss syndrome, a rare occurrence 4

Frequency of Adverse Events

The frequency of adverse events in montelukast-treated children of all ages was comparable to that in patients receiving placebo 5, 6.

Age-Related Prevalence of Adverse Drug Reactions

Adverse drug reactions were predominantly reported in children aged 4-9 years (52.8%), followed by adolescents (24.4%) and toddlers (22.8%) 3.

Management and Awareness

Pediatricians should be aware of the potential adverse drug reactions associated with montelukast, and parental counseling is necessary to address misconceptions about the drug 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Adverse Drug Reactions (ADRs) of Montelukast in Children.

Children (Basel, Switzerland), 2022

Research

Spotlight on montelukast in asthma in children 2 to 14 years of age.

American journal of respiratory medicine : drugs, devices, and other interventions, 2002

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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