Lavrez-XL Tablet is a combination medication containing Montelukast 10 mg and Fexofenadine 120 mg, indicated for the management of allergic conditions such as seasonal allergic rhinitis and chronic urticaria. Montelukast, a leukotriene receptor antagonist, works by inhibiting the action of leukotrienes, which are inflammatory mediators involved in bronchoconstriction, mucus production, and airway edema. This mechanism helps reduce airway inflammation and alleviate symptoms associated with allergic rhinitis and asthma. Fexofenadine, a second-generation antihistamine, selectively blocks peripheral H1 histamine receptors, thereby preventing histamine-induced allergic symptoms such as sneezing, nasal congestion, itching, and hives without causing significant sedation. The synergistic effect of Montelukast and Fexofenadine in Lavrez-XL provides comprehensive relief from both early and late-phase allergic responses. It is generally well tolerated, with a low incidence of adverse effects; however, patients should be monitored for hypersensitivity reactions and potential drug interactions. Lavrez-XL is administered orally, typically once daily, and should be used under medical supervision to optimize therapeutic outcomes. This combination therapy offers an effective option for patients requiring dual-action treatment to control persistent allergic symptoms and improve quality of life.