What is the primary purpose of expectorants?

Expectorants are primarily used to facilitate the clearing of mucus from the respiratory tract. By loosening secretions in the bronchial tubes, they make it easier for individuals to expel mucus when coughing. This is beneficial in conditions where mucus production is excessive or thick, often seen in colds, bronchitis, or other respiratory illnesses. The action of expectorants helps to enhance the effectiveness of coughing as a natural mechanism to clear airways, improving overall respiratory function and comfort.

The other provided options describe functions that do not align with the intended action of expectorants. For example, suppressing the cough reflex is contrary to the action of expectorants since these agents aim to promote productive coughing rather than inhibiting it. Preventing mucus formation and clearing the nasal passages pertain to different medications or interventions, as expectorants specifically target mucus thickening and encourage its expulsion from the lungs rather than inhibiting its production or addressing nasal congestion directly.