Histafex-M Tablet is a combination medication containing Montelukast 10 mg and Fexofenadine 120 mg, indicated for the management of allergic conditions such as allergic rhinitis, chronic urticaria, and asthma-related symptoms. Montelukast, a leukotriene receptor antagonist, works by blocking leukotriene D4 receptors in the airways, thereby reducing inflammation, bronchoconstriction, and mucus production. Fexofenadine, a second-generation antihistamine, selectively inhibits peripheral H1 receptors, alleviating symptoms like sneezing, nasal congestion, itching, and hives without causing significant sedation. The synergistic action of these agents provides comprehensive relief from both early and late-phase allergic responses. Histafex-M is typically administered orally once daily, with or without food, as prescribed by a healthcare professional. It is well-tolerated, though patients should be monitored for potential adverse effects such as headache, dizziness, gastrointestinal discomfort, or hypersensitivity reactions. Caution is advised in patients with hepatic or renal impairment, and it should be used under medical supervision during pregnancy and lactation. Histafex-M Tablet offers an effective therapeutic option for patients requiring combined leukotriene receptor antagonism and antihistaminic activity to control allergic symptoms and improve quality of life.