Serevent Diskus (Salmeterol) is a medication prescribed to treatasthma,chronic obstructive pulmonary disease (COPD), or exercise-induced bronchospasm. Serevent Diskus contains the medication salmeterol, which is a long-acting beta-agonist (LABA). The medication comes in a dry powder inside capsules made for inhalation. The inhaler device has a mechanism to puncture each capsule to prepare the powder for inhalation. People with diseases of the airway have trouble breathing because the muscles in the lung may contract (tighten) more often or more tightly than needed. This contraction makes the airways smaller. Serevent Diskus works by binding to beta-2 receptors on the surface of lung muscle cells. By attaching to these receptors, Serevent Diskus relaxed the muscles, making it easier to breathe.