Aerosol Drug Therapy Practice Test

DPIs rely on the patient’s own inhalation energy to disperse and aerosolize the powder, so several factors determine how well they work. The inhaled flow the patient can generate matters because DPIs require a sufficient inspiratory force to break up the powder into fine particles that can reach the lungs. If the patient can’t inhale strongly enough, de-aggregation and emission of the dose drop, reducing effectiveness. The device’s intrinsic resistance and the resulting inspiratory flow rate matter because different DPIs are designed to work best at different flow rates. A high-resistance device needs a stronger inhalation to reach the same flow, while a low-resistance one may be easier to use but still depends on achieving an adequate flow to properly de-aggregate the powder. This interaction between device design and inhalation effort shapes how much drug is emitted and deposited. Humidity and moisture exposure matter because dry powders can clump or stick when damp. Moisture reduces powder flowability, alters particle behavior, and lowers the emitted dose, leading to inconsistent dosing and less drug reaching the lungs. Since all three factors influence dose delivery and deposition, all of them affect DPI use.