Abstract: A dry powder inhaler has a slider for incrementally advancing a blister disk, to provide successive doses of a dry powder pharmaceutical. A blister disk is rotatably supported on a spindle on a deck plate of the inhaler. A powder port, an advancing slot, and a lifter slot extend through the deck plate. A slider is attached to the deck plate and movable between open and closed positions. As the slider is opened, a litter moves up on a ramp on the slider to shear open a blister, so that the blister contents can be mixed with air and inhaled. As the slider is moved back to the closed position, the lifter is withdrawn and an advancing finger turns the disk to bring the next blister into position for opening to provide the next dose to the patient.