Montelukast's Side Effects
For Parents
For Health Care Providers
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Links and Resources

Side effects from montelukast can happen at any time during treatment:

Parents have reported to Parents United for Pharmaceutical Safety and Accountability that their children began experiencing side effects days, weeks, months, and even years after treatment with montelukast began. Some parents reported they observed side effects only after a dosage increase. Parents have also reported that side effects worsened, and/or new side effects happened after a dosage increase. Some reported side effects only after stopping and restarting the medication. In addition, parents have reported that side effects took days, weeks, months or longer to completely resolve.

Montelukast has NOT been scientifically proven the most effective or safest treatment for asthma or allergies. Inhaled corticosteroids are the preferred treatment for asthma and intranasal corticosteroids are the preferred treatment for allergic rhinitis. Refer to the links on the bottom of this page for details.

Montelukast is not effective for everyone. Clinical research has determined that a person's genetic makeup determines how well it works.

10mg is the adult dosage and has not been approved for use in children.

The most up to date information on a medication can be found in the Patient Information and Prescribing Information on the website of the medication's manufacturer.

The content of the medication information leaflet you receive from your pharmacy is not approved by the FDA and may not be immediately updated when new side effects are added to a medication's Prescribing and Patient Information.

Healthcare providers may use the word "anecdotal" when referring to post-marketing adverse event reports. "Anecdotal" simply means that the reports are based on personal observation, case study reports, or random investigations rather than systematic scientific evaluation. It does not mean that the reports are inaccurate or untrue or even unlikely.

A healthcare provider may state that the risk of certain side effects/adverse reactions to montelukast is "very low". Currently, the risk for, and incidence of, side effects with this medication is UNKNOWN. So are the exact reasons why side effects happen and who will have them.


*It has come to our attention that some parents are involved in custody issues or are under the supervision of social services and may not be able to freely make decisions about their children's health. Montelukast is not medically recognized as a first line of treatment for either asthma or allergies in children. You can find supporting documentation here:

National Asthma Education and Prevention Program (NAEPP) Clinical Practice Guidelines Reference section 3, Component 4: Medications (This document states that Singulair is an alternative, but not preferred, therapy for the treatment of mild persistent asthma. For all age groups, inhaled corticosteroids are the most effective medication for long-term control.)

Diagnosis and management of rhinitis: an updated practice parameter
Page S22, [Summary Statements 74-80] Intranasal corticosteroids are the preferred treatment for allergic rhinitis and when given in recommended doses are not generally associated with clinically significant systemic side effects.


Disclaimer: Parents United for Pharmaceutical Safety and Accountability is a volunteer patient advocacy group. Consult a licensed healthcare professional before making any medical decisions. Do not stop administering an asthmatic child's medications without the supervision of the child's healthcare provider. The information on this site is intended for educational purposes and should not be construed as medical advice. It is accurate to the best of our knowledge. If you discover an inconsistency, please bring it to our attention.