The present invention relates to an inhaler which comprises a durable unit and a replaceable (cartridge) unit, and which comprises systems, subsystems and elements to provide an “open-inhale-close” user experience. A durable unit comprises a breath-actuated trigger mechanism, and optionally electronics for providing user feedback, and telehealth can capability. A replaceable unit comprises a mouthpiece, blister strip, aerosol path dose counter and a blister piercing and aerosolization engine assembly assembly. A lockout mechanism may be provided to prevent further use of the cartridge when the dose counter reaches a preselected limit, such as zero.
