Leecast-M Tablet is a combination medication containing Levocetirizine 5 mg and Montelukast 10 mg, indicated for the management of allergic conditions such as allergic rhinitis and chronic urticaria. Levocetirizine, a third-generation non-sedative antihistamine, selectively inhibits peripheral H1 receptors, thereby reducing symptoms like sneezing, nasal congestion, itching, and rhinorrhea. Montelukast, a leukotriene receptor antagonist, blocks the cysteinyl leukotriene receptor, preventing bronchoconstriction, inflammation, and mucus production associated with allergic responses. The synergistic action of these agents provides comprehensive relief from both immediate and late-phase allergic reactions. Leecast-M is particularly beneficial in patients with concomitant asthma and allergic rhinitis, improving respiratory function and quality of life. The tablet is typically administered once daily, preferably in the evening, with or without food. Common adverse effects may include headache, fatigue, dry mouth, and gastrointestinal disturbances, which are generally mild and transient. Caution is advised in patients with hepatic impairment, and it should be used under medical supervision in pediatric and elderly populations. Leecast-M Tablet should not be used in individuals with known hypersensitivity to its components. This combination therapy offers an effective and convenient approach to managing allergic disorders.