Prebronchodilators

Prebronchodilators are medications or treatments administered before the use of a bronchodilator. Their primary purpose is to enhance the effectiveness of the subsequent bronchodilator or to mitigate potential side effects. This approach is most commonly seen in the context of pulmonary function testing, specifically spirometry.

During spirometry, a bronchodilator is often given to assess the reversibility of airway obstruction. In certain diagnostic protocols, a prebronchodilator measurement of lung function is taken first. Then, a bronchodilator is administered, and a second measurement is taken after a specified waiting period. The comparison between these two sets of results helps determine if the airway obstruction is reversible, a key characteristic of asthma.

In some clinical situations, particularly when a patient is prone to experiencing bronchospasm in response to inhaled medications or stimuli, a prebronchodilator might be used. For instance, a small dose of a bronchodilator or even a different class of medication might be given prior to the main bronchodilator to "prime" the airways and reduce the likelihood of a significant adverse reaction. However, the term "prebronchodilator" is most frequently associated with the diagnostic procedure of spirometry. The specific type of prebronchodilator and its administration protocol are determined by the clinical indication and the goals of the treatment or test.