Take orally once daily in the evening, with or without food. For asthma, take in the evening. For allergic rhinitis, the time of administration can be individualized. For both asthma and allergic rhinitis, take in the evening.

Montelukast selectively antagonizes the cysteinyl leukotriene 1 (CysLT1) receptor. Leukotrienes are potent inflammatory mediators released from various cells, including mast cells and eosinophils. They bind to CysLT1 receptors in the airways and on other pro-inflammatory cells, causing bronchoconstriction, mucus secretion, vascular permeability, and eosinophil recruitment. By blocking the CysLT1 receptor, montelukast inhibits these effects, leading to bronchodilation and reduced inflammation.

• •Hypersensitivity to montelukast or any component of the tablet

Store below 30°C in a dry place, away from light and moisture. Keep out of reach of children.

Symptoms of overdose usually include abdominal pain, somnolence, thirst, headache, vomiting, and psychomotor hyperactivity. Treatment is symptomatic and supportive.

Pregnancy Category B. Studies in animals have not shown harm, but there are no adequate and well-controlled studies in pregnant women. Use during pregnancy only if clearly needed. It is unknown if montelukast is excreted in human milk; caution should be exercised when administered to a nursing mother.