Hvhist 3D Tablet SR is a combination pharmaceutical formulation containing Montelukast 10 mg, Fexofenadine 120 mg, and Acebrophylline 200 mg, designed for the management of respiratory conditions characterized by allergic inflammation, bronchoconstriction, and airway obstruction. Montelukast, a leukotriene receptor antagonist, effectively reduces bronchoconstriction and inflammation by blocking leukotriene D4 at the cysteinyl leukotriene receptor, thereby alleviating symptoms of asthma and allergic rhinitis. Fexofenadine, a second-generation antihistamine, selectively inhibits peripheral H1 receptors, providing rapid relief from allergic symptoms such as sneezing, nasal congestion, and urticaria without causing significant sedation. Acebrophylline acts as a bronchodilator and mucolytic agent, improving airway patency by relaxing bronchial smooth muscles and facilitating mucus clearance through its anti-inflammatory and antioxidant properties. The sustained-release (SR) formulation ensures prolonged therapeutic plasma levels, enhancing patient compliance by reducing dosing frequency. Hvhist 3D Tablet SR is indicated for patients with chronic obstructive pulmonary disease (COPD), bronchial asthma, and allergic rhinitis requiring multi-modal intervention to control symptoms and improve respiratory function. It should be used under medical supervision, considering contraindications, potential drug interactions, and patient-specific factors. Common adverse effects may include headache, gastrointestinal disturbances, and mild sedation.