Which drug is classified as a long-acting beta agonist?

Salmeterol is classified as a long-acting beta agonist (LABA) due to its pharmacological properties that provide prolonged bronchial dilation. LABAs are characterized by their ability to activate beta-2 adrenergic receptors in the lungs, leading to muscle relaxation in the airways and improving breathing. Salmeterol has a longer duration of action compared to short-acting beta agonists, which makes it suitable for maintenance therapy in conditions like asthma and chronic obstructive pulmonary disease (COPD). Its effects can last for up to 12 hours, making it highly beneficial for controlling symptoms over an extended period.

In contrast, albuterol is a short-acting beta agonist (SABA) that is typically used for quick relief in acute situations rather than ongoing management. Ipratropium is an anticholinergic medication, working through a different mechanism by blocking acetylcholine receptors, and does not belong to the beta agonist class at all. Fluticasone is a corticosteroid, which is used to reduce inflammation rather than directly relax airway smooth muscle. Thus, salmeterol stands out as the correct choice for a long-acting beta agonist due to its mode of action and duration of effect.