An ultrasonic aerosol generator for delivering a liquid formulation in an aerosolized form at a high output rate of greater than 0.5 mL/minute, preferably greater than 1.0 mL/minute, and with diameters in a respirable size range, methods of using this device and kits including the device are described herein. The ultrasonic aerosol generator (10) contains at least (a) a liquid reservoir/aerosolization chamber (11), (b) a piezoelectric engine (12), (c) a relief aperture (13), and (d) an aerosol delivery element (20). Preferably the aerosolized particles that are delivered to the user through the aerosol delivery element have an average aerodynamic diameter of between 1 and 20 μm, more preferably between 1 and 10 μm, and most preferably between 1 and 5 μm. Optionally, the ultrasonic aerosol generator is designed to deliver more than one formulation simultaneously, preferably a low cost and/or stable formulation is administered simultaneously with a more expensive and/or labile formulation. In the preferred embodiment, the ultrasonic aerosol generator is a hand-held device designed for a single user.