What therapeutic effect does a corticosteroid administered by metered-dose inhaler achieve in a patient with asthma?

A corticosteroid administered by a metered-dose inhaler primarily achieves its therapeutic effect in a patient with asthma by increasing the number of beta-adrenergic receptors. This action is important because corticosteroids help to reduce inflammation and hyper-responsiveness in the airways, leading to a decrease in asthma symptoms.

In particular, corticosteroids play a critical role in modulating the immune response and reducing airway inflammation, which subsequently can enhance the effectiveness of beta-agonist medications used for relieving acute asthma symptoms. The increase in beta-adrenergic receptors facilitates better responsiveness to these bronchodilators, thereby improving airflow and reducing respiratory distress.

The other options do not correctly represent the mechanism of action associated with corticosteroids in asthma management. While inflammation reduction is a key aspect of corticosteroid therapy, their direct role in receptor availability positively influences the overall therapeutic regimen for asthma patients.