API: Montelukast

What Is Montelukast and How Does It Work?

Montelukast sodium is a selective leukotriene receptor antagonist that inhibits the cysteinyl leukotriene CysLT1 receptor.1 The cysteinyl leukotrienes (LTC4, LTD4, LTE4) are released from different cells, such as mast cells and eosinophils, and bind CysLT receptors, in general. The CysLT1 receptor is found in airway smooth muscle cells and airway macrophages and on other pro-inflammatory cells, and are associated with asthma and allergic rhinitis. By inhibiting CysLT1, montelukast sodium reduces bronchoconstriction and thus causes less inflammation. The drug is used for the maintenance treatment of asthma and to relieve symptoms of seasonal allergies.2

Approved Indications

  • Asthma: Prophylaxis and chronic treatment of asthma in adults and pediatric patients 12 months of age and older.
  • Exercise-Induced Bronchoconstriction (EIB): Prevention of exercise-induced bronchoconstriction (EIB) in patients 6 years of age and older.
  • Allergic Rhinitis: 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.

Side Effects and Drug Interactions

Common side effects in patients taking montelukast include3:

  • Headache
  • Stomach pain or upset stomach,
  • Heartburn
  • Nausea
  • Diarrhea
  • Tooth pain
  • Fatigue
  • Fever, stuffy nose, sore throat, or cough
  • Mild rash

Patients who suffer from severity of these common side effects should contact their pharmacist or physician right away. Patients who experience an allergic reaction (hives, trouble breathing, swelling of the face, lips, tongue, or throat) or bruising, severe tingling, numbness or pain, muscle weakness, changes in mood or behavior, anxiety, depression or suicidal thoughts, tremors, unusual bleeding, purple or red pinpoint spots under the skin, severe sinus pain, swelling, or irritation, worsening asthma symptoms, or skin rash that is blistering and peeling should contact their physician immediately.

Patients who are allergic to montelukast should not take this drug. Patients who have acute asthma, who are taking corticosteroids, or have sensitivity to aspirin should inform their physician before taking this medication. This drug has not been well studied in pregnant and nursing patients.4

Latest News and Research

Montelukast is primarily used to treated asthma and seasonal allergies, often in conjunction with other asthma medications due to its highly specific mechanism of action (and thus lack of interaction with other agents). The drug currently has a niche market—the treatment of exercise-induced or aspirin-induced asthma. However, studies of other conditions montelukast may be useful in treating are ongoing and diverse in nature. For example, recent studies have shown that the drug has secondary anti-inflammatory properties that do not seem related to its primary mechanism of action as an agonist against cysteinyl leukotriene receptors.5 If these properties are borne out, montelukast be used in treating not only other types of asthmatic condition, such as intermittent asthma, but also conditions that involve interactions between airways epithetical cells and neutrophils, such as chronic obstructive pulmonary disease, cystic fibrosis, and viral bronchiolitis.

A second study looked at the effect of this drug on post-respiratory syncytial virus bronchiolitis in infants aged for 6 to 24 months old. The study showed that the drug reduced the degranulation of eosinophils and was associated with a decrease in recurrent wheezing episodes.6

Montelukast may also have potential in treating pediatric sleep apnea.7 The severity of pediatric obstructive sleep apnea is largely related to the size of the adenoids and tonsils; thus an adenotonsillectomy is currently the most common treatment in these patients. Since montelukast is so well tolerated, the drug may be a safe and effective treatment that saves these young patients from significant morbidity. In this 12-week study of children with non-severe obstructive sleep apnea, researchers found that montelukast delivered orally reduced the severity of the apnea as well as underlying the adenoidal hypertrophy. Such a treatment can have profound effects on pediatric cognitive, behavioral, and vascular development.

Buying Guide

Many compound pharmacists find that Dexamethasone Sodium Phosphate is an effective alternative to Montelukast. Please find more information about our Bulk APIs here.

Show 7 footnotes

  1. “Singulair,” 2009, http://www.accessdata.fda.gov/drugsatfda_docs/label/2009/020829s051_020830s052_021409s028lbl.pdf
  2. “Montelukast,” February 24, 2014, http://www.drugbank.ca/drugs/DB00471
  3. “Singulair,” April 6, 2015, http://www.rxlist.com/singulair-side-effects-drug-center.htm
  4. “Montelukast During Pregnancy, 2016, http://americanpregnancy.org/medication/montelukast-during-pregnancy/
  5. “Montelukast: More than a Cysteinyl Leukotriene Receptor Antagonist?” November 15, 2010, http://www.hindawi.com/journals/tswj/2010/625053/abs/
  6. “A Randomized Intervention of Montelukast for Post-Bronchiolitis: Effect on Eosinophil Degranulation,” May 2010, http://www.jpeds.com/article/S0022-3476(09)01224-4/abstract
  7. “Montelukast for Children With Obstructive Sleep Apnea: A Double-blind, Placebo-Controlled Study,” September 2012, http://pediatrics.aappublications.org/content/130/3/e575.short