Fluticasone Propionate and Salmeterol are combined to manage asthma and chronic obstructive pulmonary disease (COPD). Salmeterol is a long-acting bronchodilator that relaxes airway muscles and widens the airways, while Fluticasone Propionate is a corticosteroid that reduces inflammation by blocking inflammatory chemical messengers. Together, they help control symptoms, improve breathing, and reduce flare-ups.