Abstract
Increased delivery of the inhaled drug to the lungs increases the therapeutic effect until the plateau of the dose-response curve is reached. This principle is the basis of adjusting doses of all inhaled drugs, including corticosteroids. However, as has been shown with the β2 agonist terbutaline, a defined clinical effect can be obtained by a certain nominal dose from one device or a by a reduced dose from a device that achieves a higher lung delivery.3 This study investigated the Turbohaler device, which delivered about twice as much of …