Respiratory agents are medications used to treat conditions affecting the lungs and airways. They can help relieve symptoms of diseases like asthma, chronic obstructive pulmonary disease (COPD), and bronchitis. These agents work by opening airways, reducing inflammation, or thinning mucus, making it easier to breathe. Common types of respiratory agents include bronchodilators, which relax the muscles around the airways, and corticosteroids, which reduce inflammation. Other agents, like mucolytics, help break down mucus, while expectorants assist in clearing it from the lungs. Proper use of these medications can significantly improve respiratory function and overall quality of life.