Which of the following drugs is a long-acting beta agonist?

Salmeterol is classified as a long-acting beta agonist (LABA), which is a type of medication commonly used in the management of asthma and chronic obstructive pulmonary disease (COPD). LABAs are designed to provide prolonged bronchodilation, lasting up to 12 hours or more.

Salmeterol works by stimulating beta-2 adrenergic receptors in the bronchi, leading to relaxation of smooth muscle and resulting in improved airflow. This makes it particularly useful for patients who require maintenance therapy for respiratory conditions to prevent symptoms and reduce the frequency of exacerbations.

In contrast, the other substances listed have different mechanisms or classifications. Albuterol is a short-acting beta agonist (SABA), primarily used for quick relief of asthma symptoms. Fluticasone and mometasone are corticosteroids that work by reducing inflammation in the airways, providing a different approach to asthma management compared to the bronchodilation effect of LABAs.