M-LUCAS 4 MG is a chewable tablet formulation containing montelukast sodium, a selective leukotriene receptor antagonist. It is primarily indicated for the prophylaxis and chronic treatment of asthma in pediatric patients aged 2 to 5 years. Additionally, it is used for the acute prevention of exercise-induced bronchoconstriction in children aged 6 years and older, and for the relief of symptoms associated with both seasonal and perennial allergic rhinitis in children aged 2 years and older. Montelukast works by inhibiting the cysteinyl leukotriene receptor (CysLT1), thereby reducing inflammation and constriction in the airways. The recommended dosage for children aged 2 to 5 years is one 4 mg chewable tablet taken once daily in the evening. It is important to note that M-LUCAS 4 MG is not intended for the relief of acute asthma attacks and should not be used as a substitute for fast-acting bronchodilators. Patients should continue to use their prescribed rescue inhalers for such situations. As with any medication, M-LUCAS 4 MG should be used under the guidance of a healthcare professional to ensure its safety and effectiveness