| Click on "►" to expand:|
 BRAND NAMES
- International: Singulair
- Italy: Lukasm, Montegen, Singulair
- Pakinstan: Openair
- US: Singulair PI, patient information
 MECHANISM OF ACTION
Montelukast is an oral leukotriene receptor antagonist (LTRA)
Leukotrienes are a family of eicosanoid inflammatory mediators of asthma. They are generated from arachidonic acid as a result of the 5-lipoxygenase action in multiple inflammatory cells, particularly mast cells, basophils, eosinophils, neutrophils and macrophages.
Leukotrienes bind to cysteinyl leukotriene (CysLT) receptors. The CysLT type-1 (CysLT1) receptor is found in the human airway, its activation is responsible for smooth muscle contraction (bronchospasm), increase in bronchial reactivity (mucus secretion), in vascular permeability and in eosinophil recruitment in asthmatics.
Montelukast acts as an antagonist of the cysteinyl-leukotriene-receptor CysLT1, and then is able to attenuate the bronchoconstriction.
Another drug of the leukotriene receptor antagonist (LTRA) class is Zafirlukast (Accolate®). Montelukast is the preferred drug of its class due to its once daily dosing regimen, lack of pharmacokinetic interactions and unaltered food bioavailability.
- Prophylaxis and chronic treatment of asthma in patients 12 months of age and older. (Montelukast is not indicated for use in acute asthma attacks)
- Acute prevention of exercise-induced bronchoconstriction (EIB) in patients 6 years of age and older.
- Relief of symptoms of allergic rhinitis (AR): seasonal allergic rhinitis (SAR) in patients 2 years of age and older, and perennial allergic rhinitis (PAR) in patients 6 months of age and older.
15 years and older:
 DOSAGE FORMS AND STRENGTHS
- 10 mg Film Coated Tablets
- 5 mg and 4 mg Chewable Tablets
- 4 mg Oral Granules
- Hypersensitivity to any component of this product
 WARNINGS AND PRECAUTIONS
- Concomitant Corticosteroid Use: While the dose of inhaled corticosteroid may be reduced gradually under medical supervision, Montelukast should not be abruptly substituted for inhaled or oral corticosteroids.
- Neuropsychiatric events have been reported in adult, adolescent, and pediatric patients taking Montelukast. Post-marketing reports with Montelukast use include agitation, aggressive behavior or hostility, anxiousness, depression, disorientation, disturbance in attention, dream abnormalities,hallucinations, insomnia, irritability, memory impairment, restlessness, somnambulism, suicidal thinking and behavior (including suicide), and tremor.
No dose adjustment is needed when Montelukast is co-administered with theophylline, prednisone, prednisolone, oral contraceptives, terfenadine, digoxin, warfarin, gemfibrozil, itraconazole, thyroid hormones, sedative hypnotics, NSAIDs, benzodiazepines, decongestants, and Cytochrome P450 enzyme inducers.
 PREGNANCY AND LACTATION
- Pregnancy Category B (US). There are no adequate and well-controlled studies in pregnant women. Montelukast should be used during pregnancy only if clearly needed.
- Nursing Mothers: It is not known if montelukast is excreted in human milk. Because many drugs are excreted in human milk, caution should be exercised when Montelukast is given to a nursing mother.
 SIDE EFFECTS
Possible common adverse reactions : upper respiratory infection, headache, cough, epistaxis, increased ALT and somnolence.