Which one of the following best describes a metered-dose inhaler (MDI)?

A metered-dose inhaler (MDI) is designed specifically to deliver medication directly to the lungs in a fine aerosolized spray. This delivery method allows patients to receive precise doses of medication, such as bronchodilators or corticosteroids, which can rapidly affect airway inflammation and constriction. The inhalation technique is critical in ensuring that the medication reaches the target area effectively.

The other options do not accurately represent the function of an MDI. While it is true that different devices may deliver medications through various methods, the MDI’s primary purpose is to deliver inhaled medications rather than to serve as a means for allergy testing, provide oral medications in pill form, or be exclusively linked to exercise situations. Understanding the proper use of an MDI is essential for effective asthma management and treatment.