Which of the following is a classification of respiratory drugs?

Antitussives are specifically designed to suppress coughing, making them a distinct classification of respiratory drugs. These medications target the cough reflex in the brain and can be crucial in treating conditions where coughing is excessive or harmful, such as in certain respiratory infections or irritations. They help to provide relief to patients who are experiencing discomfort from persistent coughing.

On the other hand, antibiotics are primarily used to treat bacterial infections, not specifically classified as respiratory drugs since their role extends beyond the respiratory system into treating various types of infections. Analgesics are pain relievers, and while they may provide comfort to patients with respiratory issues, they are not directly classified within respiratory medications. Antivirals are designed to combat viral infections, and although they may be used in respiratory conditions, such as influenza, they do not classify as respiratory drugs specifically. Thus, antitussives stand out as a direct classification within respiratory therapies.