Histalia-M Tablet contains Levocetirizine 5 mg and Montelukast 10 mg, combining an antihistamine and a leukotriene receptor antagonist to provide effective relief from allergic conditions. Levocetirizine, a third-generation non-sedating antihistamine, selectively inhibits peripheral H1 receptors, reducing symptoms such as sneezing, nasal congestion, rhinorrhea, and pruritus associated with allergic rhinitis and chronic urticaria. Montelukast, a selective leukotriene D4 receptor antagonist, prevents leukotriene-mediated bronchoconstriction, inflammation, and mucus production, making it beneficial in managing asthma and allergic rhinitis. The synergistic action of these agents targets multiple pathways in the allergic response, improving symptom control and enhancing patient quality of life. Histalia-M is indicated for the treatment of seasonal and perennial allergic rhinitis, chronic idiopathic urticaria, and as adjunctive therapy in asthma management. It is generally well tolerated, with common adverse effects including headache, fatigue, and gastrointestinal disturbances. Caution is advised in patients with hepatic or renal impairment, and it should be used under medical supervision. This combination therapy offers a convenient once-daily dosing regimen, promoting adherence and sustained symptom relief in patients with allergic disorders.