What is the primary mechanism of action for inhaled corticosteroids?

Inhaled corticosteroids primarily act as anti-inflammatory agents that reduce airway responsiveness in conditions such as asthma and allergic rhinitis. They work by targeting the underlying inflammation in the airways, which is a key component of these conditions. By modulating the immune response, inhaled corticosteroids decrease swelling, mucus production, and airway hyperreactivity, leading to improved airflow and symptom relief.

This anti-inflammatory action occurs at multiple levels — including reducing the infiltration of inflammatory cells, downregulating the expression of adhesion molecules, and inhibiting the release of pro-inflammatory mediators. As a result, inhaled corticosteroids help prevent the exacerbation of asthma symptoms and improve overall lung function.

Other mechanisms of action listed in the choices, such as short-acting bronchodilation or muscle relaxation, are primarily associated with bronchodilators rather than corticosteroids. Inhaled corticosteroids do not inhibit leukotriene formation; rather, specific leukotriene modifiers serve that purpose. Thus, the focus on the anti-inflammatory effects aligns with the therapeutic goals in managing conditions like asthma and allergic rhinitis.