Type of aerosol device	Advantages	Disadvantages
Dry powder inhaler	Breath actuated Less patient coordination required Propellant not required Small and portable Short treatment time Dose counters in most newer designs	Requires moderate to high inspiratory flow Some units are single dose Can result in high pharyngeal deposition Not all medications available
Holding chamber, reverse-flow spacer, or spacer	Reduces need for patient coordination Reduces pharyngeal deposition	Not all medications available Many use CFC propellants in United States Inhalation can be more complex for some patients Can reduce dose available if not used properly More expensive than MDI alone Less portable than MDI alone Integral actuator devices may alter aerosol properties compared with native actuator
Pressurized MDI	Portable and compact Treatment time is short No drug preparation required No contamination of contents Dose-dose reproducibility high Some can be used with breath-actuated mouthpiece	Coordination of breathing and actuation needed Device actuation required High pharyngeal deposition Upper limit to unit dose content Remaining doses difficult to determine Potential for abuse
Small-volume jet nebulizer	Patient coordination not required Effective with tidal breathing High dose possible Dose modification possible No CFC release Can be used with supplemental oxygen Can deliver combination therapies if compatible	Not portable Pressurized gas source required Lengthy treatment time Device cleaning required Contamination possible Not all medications available in solution form Does not aerosolize suspensions well Device preparation required Performance variability Expensive when compressor added
Ultrasonic nebulizer	Patient coordination not required High dose possible Dose modification possible No CFC release Small dead volume Quiet Newer designs small and portable Faster delivery than jet nebulizer No drug loss during exhalation (breath-actuated devices)	Expensive Need for electrical power source (wall outlet or batteries) Contamination possible Not all medications available in solution form Device preparation required Does not nebulize suspensions well Possible drug degradation Potential for airway irritation with some drugs